Trial Outcomes & Findings for Tryptophan MRI in People With Schizophrenia and Healthy Controls (NCT NCT02067975)

NCT ID: NCT02067975

Last Updated: 2024-07-30

Results Overview

The following assessment was used to assess the outcome measure: the Hopkins Verbal Learning Test-Revised (HVLT-R). HVLT total scores range from 0 to 36. In order to conduct group comparisons, the HVLT raw total scores are converted to a t-score (range: -10 to 80). The mean t-scores for each condition are below (see outcome measure data table). Higher scores represent better performance. Participants performed the same task before pre- and post-treatment with Tryptophan and again with placebo (2 weeks between conditions). Change in scores pre- and post-treatment were compared between the Tryptophan and placebo conditions.

Recruitment status

COMPLETED

Study phase

PHASE2/PHASE3

Target enrollment

93 participants

Primary outcome timeframe

The order in which participants received either the tryptophan or placebo was randomized. The HVLT was administered 90 minutes prior to treatment and 4 hours post treatment. There were at least two weeks between the challenge days.

Results posted on

2024-07-30

Participant Flow

Participant milestones

Participant milestones
Measure	Schizophrenia Related Disorders: Tryptophan First, Then Placebo All participants received 6gs of placebo on the 2nd visit, and then received 6gs of tryptophan at the 3rd visit no less than two weeks apart at time zero of 7-hour visits 2 and 3. The order in which participants received either placebo or tryptophan was be randomized. The participant and the study staff did not know the order; only the pharmacist distributing the meds knew. These participants were diagnosed with Schizophrenia, Schizoaffective, or Schizophreniform.	Healthy Control: Tryptophan First, Then Placebo All participants received 6gs of placebo on the 2nd visit, and then received 6gs of tryptophan at the 3rd visit no less than two weeks apart at time zero of 7-hour visits 2 and 3. The order in which participants received either placebo or tryptophan was be randomized. The participant and the study staff did not know the order; only the pharmacist distributing the meds knew. These participants had no psychiatric conditions.	Schizophrenia Related Disorders: Placebo First, Then Tryptophan All participants received 6gs of placebo on the 2nd visit, and then received 6gs of tryptophan at the 3rd visit no less than two weeks apart at time zero of 7-hour visits 2 and 3. The order in which participants received either placebo or tryptophan was be randomized. The participant and the study staff did not know the order; only the pharmacist distributing the meds knew. These participants were diagnosed with Schizophrenia, Schizoaffective, or Schizophreniform.	Healthy Control: Placebo First, Then Tryptophan All participants received 6gs of placebo on the 2nd visit, and then received 6gs of tryptophan at the 3rd visit no less than two weeks apart at time zero of 7-hour visits 2 and 3. The order in which participants received either placebo or tryptophan was be randomized. The participant and the study staff did not know the order; only the pharmacist distributing the meds knew. These participants had no psychiatric conditions.	Schizophrenia Related Disorders: Screening Only/Not Randomized All participants had not yet completed the screening phase or been randomized. These participants were diagnosed with Schizophrenia, Schizoaffective, or Schizophreniform.	Healthy Control: Screening Only/Not Randomized All participants had not yet completed the screening phase or been randomized. These participants had no psychiatric conditions.
Overall Study STARTED	20	18	21	18	8	8
Overall Study COMPLETED	16	16	19	14	0	0
Overall Study NOT COMPLETED	4	2	2	4	8	8

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Tryptophan MRI in People With Schizophrenia and Healthy Controls

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Healthy Controls n=44 Participants All participants will receive both 6gm of tryptophan at least two weeks apart at time zero of 7 hour visits 2 and 3, and will also receive Placebo will be a liquid drink without tryptophan. 6mg at least two weeks apart at time zero of the 7 hour visits 2 and 3. The order in which participants receive either placebo or tryptophan will be randomized (ie. placebo first study visit day tryptophan on second study day, or tryptophan on first study day and placebo on second study day). Note that some of the participants included only participated in the screening and did not participate in the challenge phase of the study.	Schizophrenia Related Disorders n=49 Participants All participants will receive both 6gm of tryptophan at least two weeks apart at time zero of 7 hour visits 2 and 3, and will also receive Placebo will be a liquid drink without tryptophan. 6mg at least two weeks apart at time zero of the 7 hour visits 2 and 3. The order in which participants receive either placebo or tryptophan will be randomized (ie. placebo first study visit day tryptophan on second study day, or tryptophan on first study day and placebo on second study day). Note that some of the participants included only participated in the screening and did not participate in the challenge phase of the study.	Total n=93 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
Age, Categorical Between 18 and 65 years	44 Participants n=5 Participants	49 Participants n=7 Participants	93 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Continuous	34.75 years STANDARD_DEVIATION 11.70 • n=5 Participants	35.97959184 years STANDARD_DEVIATION 9.847778506 • n=7 Participants	35.39784946 years STANDARD_DEVIATION 10.72293335 • n=5 Participants
Sex: Female, Male Female	24 Participants n=5 Participants	16 Participants n=7 Participants	40 Participants n=5 Participants
Sex: Female, Male Male	20 Participants n=5 Participants	33 Participants n=7 Participants	53 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants	2 Participants n=7 Participants	4 Participants n=5 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
Race (NIH/OMB) Black or African American	18 Participants n=5 Participants	26 Participants n=7 Participants	44 Participants n=5 Participants
Race (NIH/OMB) White	19 Participants n=5 Participants	21 Participants n=7 Participants	40 Participants n=5 Participants
Race (NIH/OMB) More than one race	5 Participants n=5 Participants	0 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	44 participants n=5 Participants	49 participants n=7 Participants	93 participants n=5 Participants

PRIMARY outcome

Timeframe: The order in which participants received either the tryptophan or placebo was randomized. The HVLT was administered 90 minutes prior to treatment and 4 hours post treatment. There were at least two weeks between the challenge days.