Trial Outcomes & Findings for AAT + tDCS to Reduce Cue-induced Craving and Smoking Behavior (NCT NCT05426460)

Last Updated: 2025-07-10

Results Overview

Difference between cue-induced craving rating from pre-treatment (Baseline) to post-treatment (re-test) on the questionnaire on smoking urges 4-items scored 0-100. Lower values indicate more reduction in cue-induced craving.

Recruitment status

COMPLETED

Study phase

Target enrollment

41 participants

Primary outcome timeframe

Baseline to approximately 1 week

Results posted on

2025-07-10

Participant Flow

From 04/29/2022 - 5/21/2024, 179 participants were screened via telephone call. 79 passed inital phone screening and attended an in-person session in the research laboratory in a medical hospital setting where a full inclusion criteria assessment was conducted.

Of the 79 participants who attended an inital in-person session for further screening, 23 chose not to participate in the study and 15 were deemed ineligble to continue. Forty-one participants signed informed consent and were randomized. However, 3 participants were excluded from the study after randomization leaving 38 participants contributing data and completing the study.

Participant milestones

Participant milestones
Measure	AAT + tDCS Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Overall Study STARTED	12	10	11	8
Overall Study COMPLETED	11	9	10	8
Overall Study NOT COMPLETED	1	1	1	0

Reasons for withdrawal

Reasons for withdrawal
Measure	AAT + tDCS Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Overall Study Protocol Violation	1	1	1	0

Baseline Characteristics

AAT + tDCS to Reduce Cue-induced Craving and Smoking Behavior

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	AAT + tDCS n=11 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	Total n=38 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Age, Categorical Between 18 and 65 years	11 Participants n=5 Participants	9 Participants n=7 Participants	10 Participants n=5 Participants	8 Participants n=4 Participants	38 Participants n=21 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Age, Continuous	44.1 years STANDARD_DEVIATION 6.3 • n=5 Participants	42.6 years STANDARD_DEVIATION 8.7 • n=7 Participants	45.8 years STANDARD_DEVIATION 7.2 • n=5 Participants	45.8 years STANDARD_DEVIATION 7.9 • n=4 Participants	44.5 years STANDARD_DEVIATION 7.3 • n=21 Participants
Sex: Female, Male Female	6 Participants n=5 Participants	4 Participants n=7 Participants	5 Participants n=5 Participants	4 Participants n=4 Participants	19 Participants n=21 Participants
Sex: Female, Male Male	5 Participants n=5 Participants	5 Participants n=7 Participants	5 Participants n=5 Participants	4 Participants n=4 Participants	19 Participants n=21 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	1 Participants n=21 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	11 Participants n=5 Participants	9 Participants n=7 Participants	10 Participants n=5 Participants	7 Participants n=4 Participants	37 Participants n=21 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	2 Participants n=21 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Race (NIH/OMB) Black or African American	3 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants	2 Participants n=4 Participants	7 Participants n=21 Participants
Race (NIH/OMB) White	7 Participants n=5 Participants	9 Participants n=7 Participants	7 Participants n=5 Participants	4 Participants n=4 Participants	27 Participants n=21 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	2 Participants n=4 Participants	2 Participants n=21 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Region of Enrollment United States	11 participants n=5 Participants	9 participants n=7 Participants	10 participants n=5 Participants	8 participants n=4 Participants	38 participants n=21 Participants

PRIMARY outcome

Timeframe: Baseline to approximately 1 week

Population: 3 participants (2 from AAT + tDCS and 1 from AAT + sham tDCS) were excluded from analyses due to data collection error in which their ratings were not recorded.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=9 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=8 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in 4-item Questionnaire on Smoking Urges Craving Score During Cue Reactivity to Personal Cues	-36.5 score on a scale Standard Deviation 20.0	-36.3 score on a scale Standard Deviation 26.1	-36.6 score on a scale Standard Deviation 34.2	-22.2 score on a scale Standard Deviation 22.8

PRIMARY outcome

Timeframe: Baseline to approximately 1 week

Difference in mean number of cigarette smoker per day from pre-treatment (Baseline) to post-treatment (re-test). Lower number indicates greater reduction in cigarettes smoked.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=11 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=10 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=9 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Number Cigarettes Smoked Daily	-3.6 cigarettes per day Standard Deviation 3.1	-2.6 cigarettes per day Standard Deviation 4.7	-2.1 cigarettes per day Standard Deviation 5.9	-0.4 cigarettes per day Standard Deviation 6.5

PRIMARY outcome

Timeframe: Baseline to approximately 2 weeks

Difference in mean number of cigarettes smoked per day from pre-treatment (Baseline) to 1 week post treatment (follow-up). Lower number indicates greater reduction in cigarettes smoked.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=11 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Number Cigarettes Smoked Daily	-3.9 cigarettes per day Standard Deviation 2.4	-3.3 cigarettes per day Standard Deviation 5.7	-1.7 cigarettes per day Standard Deviation 5.4	-3.0 cigarettes per day Standard Deviation 6.9

PRIMARY outcome

Timeframe: Baseline to approximately 6-weeks

Population: 3 participants (1 from AAT + tDCS, 1 from AA + sham tDCS, and 1 from AC + tDCS) were lost to follow-up.

Difference in mean number of cigarette smoker per day from pre-treatment (Baseline) to 1 month post treatment (follow-up). Lower number indicates greater reduction in cigarettes smoked.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=10 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=8 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=9 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Number Cigarettes Smoked Daily	-3.8 cigarettes per day Standard Deviation 3.9	-5.5 cigarettes per day Standard Deviation 3.8	-4.3 cigarettes per day Standard Deviation 5.9	-4.6 cigarettes per day Standard Deviation 5.0

PRIMARY outcome

Timeframe: Baseline to approximately 1-week

Population: Data is missing from 2 participants (1 from AAT + tDCS and 1 from AC + sham tDCS)

Difference between Confidence to Quit score from pre-treatment (Baseline) to post-treatment (re-test) scored 0-100. More positive score reflects an increase in confidence to quit smoking.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=10 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=7 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for 5-item Confidence to Quit Questionnaire	1.0 score on a scale Standard Deviation 18.0	8.9 score on a scale Standard Deviation 20.0	3.0 score on a scale Standard Deviation 18.6	27.1 score on a scale Standard Deviation 24.3

PRIMARY outcome

Timeframe: Baseline to approximately 2-weeks

Difference between Confidence to Quit rating from pre-treatment (Baseline) to 1 week post-treatment (follow-up)

Outcome measures

Outcome measures
Measure	AAT + tDCS n=11 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for 5-item Confidence to Quit Questionnaire	-4.4 score on a scale Standard Deviation 28.4	6.9 score on a scale Standard Deviation 20.4	6.6 score on a scale Standard Deviation 17.8	20.0 score on a scale Standard Deviation 23.1

PRIMARY outcome

Timeframe: Baseline to approximately 6-weeks

Population: 3 participants were lost to follow up (1 each in groups AAT + tDCS, AAT + sham tDCS, and AC+tDCS)

Difference between Confidence to Quit rating from pre-treatment (Baseline) to 1 month post-treatment (follow-up)

Outcome measures

Outcome measures
Measure	AAT + tDCS n=10 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=8 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=9 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for 5-item Confidence to Quit Questionnaire	2.8 score on a scale Standard Deviation 24.5	13.3 score on a scale Standard Deviation 20.0	12.2 score on a scale Standard Deviation 22.4	22.8 score on a scale Standard Deviation 24.8

PRIMARY outcome

Timeframe: Baseline to approximately 1-week

Population: 2 participants are not included in the analyses due to missing data (1 from AAT + tDCS, 1 from AC + sham tDCS)

Difference between Intent to Quit score from pre-treatment (Baseline) to post-treatment (re-test). Scale is rated 1-10 from 1= "I have no thoughts about or interest in quitting smoking" to 10= "I have quit and will never go back" A positive change score indicates an increased intention to quit.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=10 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=7 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for Intent to Quit Questionnaire	1.2 score on a scale Standard Deviation 1.0	0.4 score on a scale Standard Deviation 0.9	-0.2 score on a scale Standard Deviation 0.8	0.7 score on a scale Standard Deviation 1.6

PRIMARY outcome

Timeframe: Baseline to approximately 2-weeks

Difference between Intent to Quit score from pre-treatment (Baseline) to 1 week post-treatment (follow-up). Scale is rated 1-10 from 1= "I have no thoughts about or interest in quitting smoking" to 10= "I have quit and will never go back" A positive change score indicates an increased intention to quit.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=11 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=9 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=10 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for Intent to Quit Questionnaire	1.3 score on a scale Standard Deviation 1.2	0.9 score on a scale Standard Deviation 0.6	-0.3 score on a scale Standard Deviation 0.9	1.1 score on a scale Standard Deviation 1.5

PRIMARY outcome

Timeframe: Baseline to approximately 6-weeks

Population: Data from 3 participants (1 from AAT + tDCS, 1 From AAT + sham tDCS, and 1 from AC + tDCS) were lost to follow-up

Difference between Intent to Quit score from pre-treatment (Baseline) to 1 month post-treatment (follow-up). Scale is rated 1-10 from 1= "I have no thoughts about or interest in quitting smoking" to 10= "I have quit and will never go back" A positive change score indicates an increased intention to quit.

Outcome measures

Outcome measures
Measure	AAT + tDCS n=10 Participants Approach Avoidance Task + Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions.	AAT + Sham tDCS n=8 Participants Approach Avoidance Task with Sham Transcranial Direct Current Stimulation. Approach/Avoidance Task: The Approach/avoidance task (AAT) training is done using a joystick. The AAT tasks involves having participants push away pictures of smoking stimuli that appear on the screen by pushing the joystick forward, and pulling in pictures of nonsmoking stimuli that appear on the screen by pulling the joystick towards themselves. Pushing smoking-related pictures away causes the picture to shrink in size, whereas pulling a picture closer causes the picture to increase in size. This task consists of 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.	AC + tDCS n=9 Participants Active Control Task with Transcranial Direct Current Stimulation targeting the dorsolateral prefrontal cortex Transcranial Direct Current Stimulation: Transcranial Direct Current Stimulation active (2.0 mA) (tDCS) will be used to temporarily increase cortical excitability of the dorsolateral prefrontal cortex (dlPFC) in healthy daily smokers. Participants assigned to active tDCS conditions will receive active (2.0 mA) tDCS, with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. tDCS will be administered the first 20 minutes of each of the five 30 minute AAT training sessions. AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes.	AC + Sham tDCS n=8 Participants Active Control Task with sham Transcranial Direct Current Stimulation AC: During Active Control (AC) participants press a button on the left of right of the joystick to indicate the position the picture on a screen. Position of pictures will be balanced across the 4 blocks of 24 pictures, taking 30 minutes. Sham tDCS: Sham transcranial Direct Current Stimulation (0.1 mA) (sham tDCS) will be used as a control for active tDCS with anode electrode placement over the right dlPFC and cathode electrode placement over the left bicep. Sham tDCS will be administered during the first 20 minutes of each of the four blocks of 24 pictures, taking 30 minutes, across the 5 training sessions.
Mean Change From Baseline in Rating Score for Intent to Quit Questionnaire	1.4 score on a scale Standard Deviation 1.3	1.3 score on a scale Standard Deviation 1.4	0.6 score on a scale Standard Deviation 1.7	1.3 score on a scale Standard Deviation 1.8

Adverse Events

AAT + tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

AAT + Sham tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

AC + tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

AC + Sham tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Cynthia Conklin

University of Pittsburgh

Phone: 4125869840

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place