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

Primary Purpose

Schizophrenia

Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
N-Acetylcysteine
Placebo
Sponsored by
Yale University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Schizophrenia focused on measuring Schizophrenia, working memory, N-Acetylcysteine

Eligibility Criteria

18 Years - 60 Years (Adult)All SexesDoes not accept healthy volunteers

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

Sites / Locations

  • Connecticut Mental Health Center

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Placebo Comparator

Arm Label

Group A: Intervention/Placebo

Group B: Placebo/Intervention

Arm Description

Group A first receives the commercially available sustained release form of N-acetylcysteine, then the matching placebo capsules both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).

Group B first receives the placebo and then receives a commercially available sustained release form of N-Acetylcysteine. In each arm, the capsules are both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).

Outcomes

Primary Outcome Measures

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.
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.
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.
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.
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.
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.
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.

Secondary Outcome Measures

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.

Full Information

First Posted
February 25, 2010
Last Updated
November 4, 2015
Sponsor
Yale University
Collaborators
National Alliance for Research on Schizophrenia and Depression
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1. Study Identification

Unique Protocol Identification Number
NCT01232790
Brief Title
A Pilot Trial of Acute N-Acetylcysteine Effects on Working Memory and Other Cognitive Functions in Schizophrenia
Acronym
NAC
Official Title
A Pilot Trial of Acute N-Acetylcysteine Effects on Working Memory and Other Cognitive Functions in Schizophrenia
Study Type
Interventional

2. Study Status

Record Verification Date
November 2015
Overall Recruitment Status
Completed
Study Start Date
February 2010 (undefined)
Primary Completion Date
November 2011 (Actual)
Study Completion Date
November 2011 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Yale University
Collaborators
National Alliance for Research on Schizophrenia and Depression

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief 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.
Detailed 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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Schizophrenia
Keywords
Schizophrenia, working memory, N-Acetylcysteine

7. Study Design

Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
28 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Group A: Intervention/Placebo
Arm Type
Experimental
Arm Description
Group A first receives the commercially available sustained release form of N-acetylcysteine, then the matching placebo capsules both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).
Arm Title
Group B: Placebo/Intervention
Arm Type
Placebo Comparator
Arm Description
Group B first receives the placebo and then receives a commercially available sustained release form of N-Acetylcysteine. In each arm, the capsules are both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).
Intervention Type
Dietary Supplement
Intervention Name(s)
N-Acetylcysteine
Intervention Description
N-acetylcysteine 1200mg bid for 3 days
Intervention Type
Drug
Intervention Name(s)
Placebo
Intervention Description
Placebo
Primary Outcome Measure Information:
Title
BACS Composite RAW Score
Description
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.
Time Frame
Baseline
Title
BACS Composite RAW Score
Description
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.
Time Frame
Follow Up (5 days)
Title
BACS Composite RAW Score
Description
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.
Time Frame
Change from Baseline at Follow Up (5 days)
Title
BACS Composite RAW Score
Description
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.
Time Frame
Baseline 1st Leg of Crossover
Title
BACS Composite RAW Score
Description
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.
Time Frame
Follow Up 1st Leg of Crossover (5 Days)
Title
BACS Composite RAW Score
Description
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.
Time Frame
Baseline 2nd Leg of Crossover
Title
BACS Composite RAW Score
Description
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.
Time Frame
Follow Up 2nd Leg of Crossover (5 Days)
Secondary Outcome Measure Information:
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Baseline
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Follow Up (5 days)
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Change from Baseline at Follow Up (5 days)
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Baseline 1st Leg of Crossover
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Follow Up 1st Leg of Crossover (5 Days)
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Baseline 2nd Leg of Crossover
Title
Letter/Number Sequencing Task Tests for Attention, Concentration & Mental Control (LNS) RAW SCORE.
Description
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.
Time Frame
Follow Up 2nd Leg of Crossover (5 Days)
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Baseline
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Follow Up (5 days)
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Change from Baseline at Follow Up (Baseline - Follow Up)
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Baseline 1st Leg of Crossover
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Follow Up 1st Leg of Crossover (5 Days)
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Baseline 2nd Leg of Crossover
Title
Brief Visuospatial Memory Test (BVMT) RAW SCORE.
Description
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.
Time Frame
Follow Up 2nd Leg of Crossover (5 Days)
Title
Brief Psychiatric Rating Scale (BPRS)Total Score
Description
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.
Time Frame
Pre Screening
Title
Brief Psychiatric Rating Scale (BPRS)Total Score
Description
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.
Time Frame
End of Trial
Title
Brief Psychiatric Rating Scale (BPRS)Total Score
Description
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.
Time Frame
Change from PreScreening at End of Trial

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
60 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
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
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Cenk Tek, MD
Organizational Affiliation
Yale University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Connecticut Mental Health Center
City
New Haven
State/Province
Connecticut
ZIP/Postal Code
06519
Country
United States

12. IPD Sharing Statement

Learn more about this trial

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

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