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

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)

Population: Per protocol

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)

Population: Subjects analyzed are those with complete data at follow up and does not include those that had dropped from the study.

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)

Population: Subjects analyzed are only those with complete data at baseline and 5 day follow up in the study.

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

Population: Subjects analyzed are those with complete data at baseline prior to dropout from the study.

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

Population: Subjects analyzed are those with complete data at baseline prior to dropout from the study.

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)

Population: Subjects analyzed are those with complete data at follow up and does not include those dropped out from the study.

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

Population: Subjects analyzed are those with complete data at baseline prior to dropout from the study.

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

Population: Analyses only used matched cases and does not include participants with incomplete data.

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

Population: Per protocol

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

Population: Per protocol

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

Population: All participants were analyzed that had baseline data collected (including any that did not complete the time frame).

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)

Population: Per protocol

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

Population: Subjects analyzed are those with complete data at 2nd baseline in the crossover and could include those that had dropped from the study if data was collected prior to drop out.

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)

Population: Per protocol

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)

Population: Subjects analyzed are those with complete data at all timepoints and does not include those that had dropped from the study.

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

Population: Per protocol

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)

Population: Subjects analyzed are those with complete data at follow up in the crossover and does not include those that had dropped from the study.

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

Population: Subjects analyzed are those with complete data at 2nd baseline in the crossover and could include those that had dropped from the study if data was collected prior to drop out.

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

Population: Subjects analyzed are those with complete data at baseline prior to dropout from the study.

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)

Population: Subjects analyzed are those with complete data at follow up and does not include those that had dropped from the study.

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)

Population: Subjects analyzed are those with complete data at follow up and does not include those that had dropped from the study.

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

Population: All participants were analyzed that had baseline data collected (including any that did not complete the time frame).

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)

Population: Subjects analyzed are those with complete data at follow up and does not include those that had dropped from the study.

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)

Population: Subjects analyzed are those with complete data at 2nd follow up in the crossover and does not include those that had dropped from the study.