Trial Outcomes & Findings for The Effects of tDCS on the Neuronal Mechanisms of Cognitive Control in Schizophrenia (NCT NCT03077347)
NCT ID: NCT03077347
Last Updated: 2024-06-13
Results Overview
Blood oxygen level-dependent response of the dorsolateral prefrontal cortex during a cognitive control task (Dot-Probe Expectancy Task)
Recruitment status
TERMINATED
Study phase
NA
Target enrollment
6 participants
Primary outcome timeframe
Assessment will begin immediately following stimulation and last for up to an hour.
Results posted on
2024-06-13
Participant Flow
Participant milestones
| Measure |
Sham First, Then Experimental Stimulation
Sham: Very brief 2 mA constant stimulation (\~1 minute). Experimental: 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex.
Transcranial Direct Current Stimulation: In tDCS, saline-soaked electrodes are temporary affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (\~20 minutes) to stimulate the targeted brain area (e.g. the DLPFC). To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
In this arm, sham was given first, followed by a washout period of 24-48 hours, followed by the experimental TDCS stimulation.
|
Experimental Stimulation First, Then Sham
Experimental: 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Sham: Very brief 2 mA constant stimulation (\~1 minute).
Transcranial Direct Current Stimulation: In tDCS, saline-soaked electrodes are temporary affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (\~20 minutes) to stimulate the targeted brain area (e.g. the DLPFC). To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
In this arm, the experimental TDCS stimulation was given first, followed by a washout period of 24-48 hours, followed by sham.
|
|---|---|---|
|
Sham Stimulation (1-20 Minutes)
STARTED
|
3
|
3
|
|
Sham Stimulation (1-20 Minutes)
COMPLETED
|
3
|
3
|
|
Sham Stimulation (1-20 Minutes)
NOT COMPLETED
|
0
|
0
|
|
Washout (24-48 Hours)
STARTED
|
3
|
3
|
|
Washout (24-48 Hours)
COMPLETED
|
3
|
3
|
|
Washout (24-48 Hours)
NOT COMPLETED
|
0
|
0
|
|
Experimental Stimulation (1-20 Minutes)
STARTED
|
3
|
3
|
|
Experimental Stimulation (1-20 Minutes)
COMPLETED
|
3
|
3
|
|
Experimental Stimulation (1-20 Minutes)
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
The Effects of tDCS on the Neuronal Mechanisms of Cognitive Control in Schizophrenia
Baseline characteristics by cohort
| Measure |
Sham Followed by Experimental Stimulation
n=3 Participants
This study will use a crossover design. In this arm, the sham stimulation is followed by a 24-48 hour washout period, followed by experimental stimulation.
Experimental Intervention: 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Sham: 1 minute fo 2 mA direct current stimulation over the dorsolateral prefrontal cortex
Transcranial Direct Current Stimulation: In tDCS, saline-soaked electrodes are temporary affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (\~20 minutes) to stimulate the targeted brain area (e.g. the DLPFC). To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation. The study will use a crossover design.
To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
I
|
Experimental Stimulation Followed by Sham
n=3 Participants
This study will use a crossover design. In this arm, the experimental stimulation is followed by a 24-48 hour washout period, followed by sham stimulation.
Experimental Intervention: 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Sham: 1 minute fo 2 mA direct current stimulation over the dorsolateral prefrontal cortex
Transcranial Direct Current Stimulation: In tDCS, saline-soaked electrodes are temporary affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (\~20 minutes) to stimulate the targeted brain area (e.g. the DLPFC). To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation. The study will use a crossover design.
To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
|
Total
n=6 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
3 Participants
n=93 Participants
|
3 Participants
n=4 Participants
|
6 Participants
n=27 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Age, Continuous
|
21 years
STANDARD_DEVIATION 3 • n=93 Participants
|
21 years
STANDARD_DEVIATION 3 • n=4 Participants
|
21 years
STANDARD_DEVIATION 3 • n=27 Participants
|
|
Sex: Female, Male
Female
|
2 Participants
n=93 Participants
|
1 Participants
n=4 Participants
|
3 Participants
n=27 Participants
|
|
Sex: Female, Male
Male
|
1 Participants
n=93 Participants
|
2 Participants
n=4 Participants
|
3 Participants
n=27 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Race (NIH/OMB)
Asian
|
2 Participants
n=93 Participants
|
1 Participants
n=4 Participants
|
3 Participants
n=27 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Race (NIH/OMB)
Black or African American
|
1 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
1 Participants
n=27 Participants
|
|
Race (NIH/OMB)
White
|
0 Participants
n=93 Participants
|
2 Participants
n=4 Participants
|
2 Participants
n=27 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
|
Region of Enrollment
United States
|
3 participants
n=93 Participants
|
3 participants
n=4 Participants
|
6 participants
n=27 Participants
|
PRIMARY outcome
Timeframe: Assessment will begin immediately following stimulation and last for up to an hour.Blood oxygen level-dependent response of the dorsolateral prefrontal cortex during a cognitive control task (Dot-Probe Expectancy Task)
Outcome measures
| Measure |
Sham Stimulation
n=6 Participants
To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
|
Experimental Stimulation
n=6 Participants
20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex
|
|---|---|---|
|
Dorsolateral Prefrontal Cortex Response
|
1.46 beta weights of DLPFC fMRI activations
Standard Deviation .76
|
1.49 beta weights of DLPFC fMRI activations
Standard Deviation 2.08
|
PRIMARY outcome
Timeframe: Assessment will begin immediately following stimulation and last for up to an hour.Cognitive control-related performance (d-prime context) associated with the task (Dot-Probe Expectancy Task). The d-prime context index was calculated by computing a d-prime index from hits on AX trials and false alarms on BX trials as Z(H) - Z(F), with H representing hits on AX trials, F representing false alarms on BX trials, and Z representing the z-transform of a value. Positive d-prime values indicate more cognitive control, and negative values indicate less cognitive control.
Outcome measures
| Measure |
Sham Stimulation
n=6 Participants
To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (\~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.
|
Experimental Stimulation
n=6 Participants
20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex
|
|---|---|---|
|
Behavioral Response
|
3.35 d-prime context
Standard Deviation .25
|
3.12 d-prime context
Standard Deviation .91
|
Adverse Events
Sham Stimulation
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Experimental Stimulation
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
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place