A Pilot Trial of Acute N-Acetylcysteine Effects on Working Memory and Other Cognitive Functions in Schizophrenia

Schizophrenia Clinical Trial

— NAC  

Official title:

A Pilot Trial of Acute N-Acetylcysteine Effects on Working Memory and Other Cognitive Functions in Schizophrenia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01232790
• Other study ID #: 0904005039
• Secondary ID: M131976
• Status: Completed
• Phase: N/A
• First received: February 25, 2010
• Last updated: November 4, 2015
• Start date: February 2010
• Est. completion date: November 2011

Study information

• Verified date: November 2015
• Source: Yale University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to evaluate the effects of the amino acid supplement N-Acetylcysteine versus placebo on working memory and other cognitive functions in persons with a diagnosis of schizophrenia.

Description:

Working memory impairment in Schizophrenia is produced by deficiencies of feedback inhibition of glutamate release, due to low cysteine-glutamate antiporter activity. Because of this mechanism, we are interested in whether acute administration of N-Acetylcysteine will improve performance of patients with schizophrenia on a battery of cognitive tasks utilized to test working memory and other cognitive domains, versus placebo. This pilot study will utilize a randomized, double blind, placebo controlled, crossover design.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 28
• Est. completion date: November 2011
• Est. primary completion date: November 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• Subjects will be between 18-60

• Meet Diagnostic and Statistical Manual-IV (DSM) criteria for schizophrenia

• Be on a stable dose of antipsychotic medication for at least 1 month

• Be deemed clinically stable for 3 months by the regular clinical staff

Exclusion Criteria:

• Current substance or alcohol abuse

• Pregnancy

• Clozapine treatment

• Known sensitivity to sulphur containing compounds

• Previous diagnosis of mental retardation

• Nitroglycerin use

• Asthma diagnosis, verified and treated by a primary care doctor

• Use of any other medication that may interact with the study medication

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Schizophrenia

Intervention

Dietary Supplement:
• N-Acetylcysteine
N-acetylcysteine 1200mg bid for 3 days

Drug:
• Placebo
Placebo

Locations

Country	Name	City	State
United States	Connecticut Mental Health Center	New Haven	Connecticut

Sponsors (2)

Lead Sponsor	Collaborator
Yale University	National Alliance for Research on Schizophrenia and Depression

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Baseline	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Follow Up (5 days)	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Change from Baseline at Follow Up (5 days)	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Baseline 1st Leg of Crossover	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Follow Up 1st Leg of Crossover (5 Days)	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Baseline 2nd Leg of Crossover	No
Primary	BACS Composite RAW Score	The Brief Assessment of Cognition in Schizophrenia (BACS) is an instrument that assesses the aspects of cognition found to be most impaired and most strongly correlated with outcome in patients with schizophrenia.; The BACS composite raw score the total of the raw scores for the 6 subtests of the BACS (Verbal memory, token motor, digit sequencing, verbal fluency, symbol coding and executive functioning). The range, so we could be from 0-435. A high score total score is more favorable and indicates a higher level of cognition.; The BACS requires less than 35 min to complete in patients with schizophrenia, yields a high completion rate in these patients, and has high reliability. The BACS was found to be as sensitive to cognitive impairment in patients with schizophrenia as a standard battery of tests that required over 2 h to administer. It is the raw sum of the test items and higher scores are favorable.	Follow Up 2nd Leg of Crossover (5 Days)	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Baseline	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Follow Up (5 days)	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Change from Baseline at Follow Up (5 days)	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Baseline 1st Leg of Crossover	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Follow Up 1st Leg of Crossover (5 Days)	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Baseline 2nd Leg of Crossover	No
Secondary	Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.	Letter Number Sequencing (LNS) is a brief, standardized executive function task used to assess verbal working memory performance. The test involves a 24-item Experimental Condition, in which participants are read a series of letters and numbers and asked to recite both back in ascending order, with the numbers first and then the letters. Participants receive one point for each correct answer for a range of 0-24. Higher scores are better.	Follow Up 2nd Leg of Crossover (5 Days)	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Baseline	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Follow Up (5 days)	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Change from Baseline at Follow Up (Baseline - Follow Up)	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Baseline 1st Leg of Crossover	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Follow Up 1st Leg of Crossover (5 Days)	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Baseline 2nd Leg of Crossover	No
Secondary	Brief Visuospatial Memory Test (BVMT) RAW SCORE.	Brief Visuospatial Memory Test (BVMT) is a measure of visuospatial memory. This task includes three trials of six geometric figures printed in a 2 x 3 array on separate pages. The respondent views the stimulus page for 10 seconds and is asked to draw as many of the figures as possible in their correct location on a page in the response booklet. A Delayed Recall Trial is administered after a 25-minute delay. Scoring is based on accuracy of the figure as well as its location on the page. A range of 0-12 per trial is possible(0-36 total). Higher scores are better.	Follow Up 2nd Leg of Crossover (5 Days)	No
Secondary	Brief Psychiatric Rating Scale (BPRS)Total Score	Brief Psychiatric Rating Scale (BPRS) utilized before and after treatment. BPRS total score is a total of the 18 item scores with a range of 18-126. It is used to measure schizophrenia symptoms and to assess change in them over time. There are 18 symptom sub scores. Each symptom is rated 1-7 (not present to extremely severe) and then all items are summed for the total score. Higher scores indicate more severe symptoms.; The BPRS is the gold-standard overall measure of schizophrenia symptoms which will be utilized to demonstrate that the intervention does not cause worsening of the illness symptoms apart from the usual fluctuations of the natural course.	Pre Screening	Yes
Secondary	Brief Psychiatric Rating Scale (BPRS)Total Score	Brief Psychiatric Rating Scale (BPRS) utilized before and after treatment. BPRS total score is a total of the 18 item scores with a range of 18-126. It is used to measure schizophrenia symptoms and to assess change in them over time. There are 18 symptom sub scores. Each symptom is rated 1-7 (not present to extremely severe) and then all items are summed for the total score. Higher scores indicate more severe symptoms.; The BPRS is the gold-standard overall measure of schizophrenia symptoms which will be utilized to demonstrate that the intervention does not cause worsening of the illness symptoms apart from the usual fluctuations of the natural course.	End of Trial	Yes
Secondary	Brief Psychiatric Rating Scale (BPRS)Total Score	Brief Psychiatric Rating Scale (BPRS) utilized before and after treatment. BPRS total score is a total of the 18 item scores with a range of 18-126. It is used to measure schizophrenia symptoms and to assess change in them over time. There are 18 symptom sub scores. Each symptom is rated 1-7 (not present to extremely severe) and then all items are summed for the total score. Higher scores indicate more severe symptoms.; The BPRS is the gold-standard overall measure of schizophrenia symptoms which will be utilized to demonstrate that the intervention does not cause worsening of the illness symptoms apart from the usual fluctuations of the natural course.	Change from PreScreening at End of Trial	Yes