A preliminary investigation on the efficacy of N-acetyl cysteine for mania or hypomania.

OBJECTIVE: Oxidative imbalance has emerged as a treatment target in bipolar disorder. As very limited data are available on the clinical use of antioxidants for mania, we report here results from a post hoc and exploratory subgroup analysis of a randomized, placebo-controlled trial of N-acetyl cysteine (NAC). METHODS: This was a placebo-controlled, randomized, clinical trial assessing the effect of NAC over 24 weeks in mania or hypomania. Symptomatic and functional outcomes were collected over the study period. RESULTS: Fifteen participants were available for this report; two participants in each group failed to complete all assessments. Within-group analyses pointed to an improvement in the NAC group on manic symptoms and worsening in the placebo group on depressive symptoms at endpoint. CONCLUSIONS: Although the sample size was small, these results indicated within-group efficacy for this glutathione precursor as compared to placebo. Future trials specifically designed to demonstrate the efficacy of NAC in mania are needed.

Effects of N-acetyl cysteine on cognitive function in bipolar disorder.

AIMS: Bipolar disorder is characterized by progressive changes in cognition with declines in executive functioning, memory and sustained attention. Current pharmacotherapies for bipolar disorder target mood symptoms but have not addressed these cognitive changes resulting in euthymic individuals who still experience cognitive deficits. N-acetyl cysteine (NAC) has been shown to have effects on antioxidant status, glutamate transmission, inflammation and neurogenesis. Adjunctive treatment with NAC improves the symptoms experienced by those with bipolar disorder, particularly depression, and it was hypothesized that cognition may also be improved following NAC treatment. METHODS: As part of a larger randomized, double-blind, placebo-controlled trial, participants in the current report were tested at baseline and 6 months to assess changes in cognitive function following either 2000 mg of NAC daily or placebo. RESULTS: This study failed to find changes in cognitive function following treatment with NAC compared to placebo. CONCLUSIONS: While an important pilot study, this study had a small sample size and included a limited battery of cognitive tests. Further investigations on the effects of NAC on cognitive performance in bipolar disorder are required.

N-acetylcysteine for major depressive episodes in bipolar disorder.

OBJECTIVE: In this report, we aimed to evaluate the effect of add-on N-acetylcysteine (NAC) on depressive symptoms and functional outcomes in bipolar disorder. To that end, we conducted a secondary analysis of all patients meeting full criteria for a depressive episode in a placebo controlled trial of adjunctive NAC for bipolar disorder. METHOD: Twenty-four week randomised clinical trial comparing adjunctive NAC and placebo in individuals with bipolar disorder experiencing major depressive episodes. Symptomatic and functional outcome data were collected over the study period. RESULTS: Seventeen participants were available for this report. Very large effect sizes in favor of NAC were found for depressive symptoms and functional outcomes at endpoint. Eight of the ten participants on NAC had a treatment response at endpoint; the same was true for only one of the seven participants allocated to placebo. DISCUSSION: These results indicate that adjunctive NAC may be useful for major depressive episodes in bipolar disorder. Further studies designed to confirm this hypothesis are necessary.

N-acetylcysteine for major depressive episodes in bipolar disorder / N-acetilcisteína para o tratamento de episódios de depressão maior no transtorno bipolar

OBJECTIVE: In this report, we aimed to evaluate the effect of add-on N-acetylcysteine (NAC) on depressive symptoms and functional outcomes in bipolar disorder. To that end, we conducted a secondary analysis of all patients meeting full criteria for a depressive episode in a placebo controlled trial of adjunctive NAC for bipolar disorder. METHOD: Twenty-four week randomised clinical trial comparing adjunctive NAC and placebo in individuals with bipolar disorder experiencing major depressive episodes. Symptomatic and functional outcome data were collected over the study period. RESULTS: Seventeen participants were available for this report. Very large effect sizes in favor of NAC were found for depressive symptoms and functional outcomes at endpoint. Eight of the ten participants on NAC had a treatment response at endpoint; the same was true for only one of the seven participants allocated to placebo. DISCUSSION: These results indicate that adjunctive NAC may be useful for major depressive episodes in bipolar disorder. Further studies designed to confirm this hypothesis are necessary.

OBJETIVO: Neste relato, avaliamos o efeito da N-acetilcisteína (NAC) adjuvante em sintomas depressivos e desfechos funcionais no transtorno bipolar. Para isso, conduzimos uma análise secundária de todos os pacientes com critérios diagnósticos para um episódio depressivo em um ensaio clínico randomizado comparando NAC adjuvante com placebo no transtorno bipolar. MÉTODO: Ensaio clínico randomizado comparando NAC adjuvante com placebo para episódios depressivos no transtorno bipolar durante 24 semanas. Desfechos funcionais e sintomáticos foram coletados no período. RESULTADOS: Dezessete participantes estavam disponíveis para esta análise. Tamanhos de efeito grandes foram encontrados para sintomas depressivos e desfechos funcionais. Oito dos dez participantes no grupo da NAC tiveram resposta clínica ao fim do tratamento. O mesmo ocorreu em apenas um dos sete que receberam placebo. DISCUSSÃO: Esses resultados indicam que a NAC adjuvante pode ser útil para episódios de depressão maior no transtorno bipolar. Estudos desenhados para confirmar esta hipótese são necessários.

Qualitative methods in early-phase drug trials: broadening the scope of data and methods from an RCT of N-acetylcysteine in schizophrenia.

OBJECTIVE: The pharmacokinetic profile of a drug often gives little indication of its potential therapeutic application, with many therapeutic uses of drugs being discovered serendipitously while being studied for different indications. As hypothesis-driven, quantitative research methodology is exclusively used in early-phase trials, unexpected but important phenomena may escape detection. In this context, this study aimed to examine the potential for integrating qualitative research methods with quantitative methods in early-phase drug trials. To our knowledge, this mixed methodology has not previously been applied to blinded psychopharmacologic trials. METHOD: We undertook qualitative data analysis of clinical observations on the dataset of a randomized, double-blind, placebo-controlled trial of N-acetylcysteine (NAC) in patients with DSM-IV-TR-diagnosed schizophrenia (N = 140). Textual data on all participants, deliberately collected for this purpose, were coded using NVivo 2, and emergent themes were analyzed in a blinded manner in the NAC and placebo groups. The trial was conducted from November 2002 to July 2005. RESULTS: The principal findings of the published trial could be replicated using a qualitative methodology. In addition, significant differences between NAC- and placebo-treated participants emerged for positive and affective symptoms, which had not been captured by the rating scales utilized in the quantitative trial. Qualitative data in this study subsequently led to a positive trial of NAC in bipolar disorder. CONCLUSIONS: The use of qualitative methods may yield broader data and has the potential to complement traditional quantitative methods and detect unexpected efficacy and safety signals, thereby maximizing the findings of early-phase clinical trial research. TRIAL REGISTRATION: www.anzctr.org.au Identifier: ACTRN12605000363684.

Effects of N-acetylcysteine on substance use in bipolar disorder: A randomised placebo-controlled clinical trial.

OBJECTIVE: To evaluate the effect of N-acetylcysteine (NAC) on substance use in a double-blind, placebo-controlled trial of NAC in bipolar disorder. It is hypothesised that NAC will be superior to placebo for reducing scores on the Clinical Global Impressions scale for Substance Use (CGI-SU). METHODS: Participants were randomised to a 6-months of treatment with 2 g/day NAC (n = 38) or placebo (n = 37). Substance use was assessed at baseline using a Habits instrument. Change in substance use was assessed at regular study visits using the CGI-SU. RESULTS: Among the 75 participants 78.7% drank alcohol (any frequency), 45.3% smoked tobacco and 92% consumed caffeine. Other substances were used by fewer than six participants. Caffeine use was significantly lower for NAC-treated participants compared to placebo at week 2 of treatment but not at other study visits. CONCLUSIONS: NAC appeared to have little effect on the participants who were using substances. A larger study on a substance-using population will be necessary to determine if NAC may be a useful treatment for substance use.

Effects of N-acetylcysteine on substance use in bipolar disorder: a randomised placebo-controlled clinical trial.

OBJECTIVE: To evaluate the effect of N-acetylcysteine (NAC) on substance use in a double-blind, placebo-controlled trial of NAC in bipolar disorder. It is hypothesised that NAC will be superior to placebo for reducing scores on the Clinical Global Impressions scale for Substance Use (CGI-SU). METHODS: Participants were randomised to 6-months of treatment with 2 g/day NAC (n = 38) or placebo (n = 37). Substance use was assessed at baseline using the Habits instrument. Change in substance use was assessed at regular study visits using the CGI-SU. RESULTS: Amongst the 75 participants 78.7% drank alcohol (any frequency), 45.3% smoked tobacco and 92% consumer caffeine. Other substances were used by fewer than six participants. Caffeine use was significantly lower for NAC-treated participants compared with placebo at week 2 of treatment but not at other study visits. CONCLUSION: NAC appeared to have little effect on substance use in this population. A larger study on a substance using population will be necessary to determine if NAC may be a useful treatment for substance use.

N-acetyl cysteine for depressive symptoms in bipolar disorder--a double-blind randomized placebo-controlled trial.

BACKGROUND: Treatment-resistant subthreshold depression is a major problem in bipolar disorder. Both depression and bipolar disorder are complicated by glutathione depletion. We hypothesized that treatment with N-acetyl cysteine (NAC), a safe, orally bioavailable precursor of glutathione, may improve the depressive component of bipolar disorder. METHODS: A randomized, double-blind, multicenter, placebo-controlled study of individuals (n = 75) with bipolar disorder in the maintenance phase treated with NAC (1 g twice daily) adjunctive to usual medication over 24 weeks, with a 4-week washout. The two primary outcomes were the Montgomery Asberg Depression Rating Scale (MADRS) and time to a mood episode. Secondary outcomes included the Bipolar Depression Rating Scale and 11 other ratings of clinical status, quality of life, and functioning. RESULTS: NAC treatment caused a significant improvement on the MADRS (least squares mean difference [95% confidence interval]: -8.05 [-13.16, -2.95], p = .002) and most secondary scales at end point. Benefit was evident by 8 weeks on the Global Assessment of Functioning Scale and Social and Occupational Functioning Assessment Scale and at 20 weeks on the MADRS. Improvements were lost after washout. There was no effect of NAC on time to a mood episode (log-rank test: p = .968) and no significant between-group differences in adverse events. Effect sizes at end point were medium to high for improvements in MADRS and 9 of the 12 secondary readouts. CONCLUSIONS: NAC appears a safe and effective augmentation strategy for depressive symptoms in bipolar disorder.

N-acetyl cysteine as a glutathione precursor for schizophrenia--a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Brain glutathione levels are decreased in schizophrenia, a disorder that often is chronic and refractory to treatment. N-acetyl cysteine (NAC) increases brain glutathione in rodents. This study was conducted to evaluate the safety and effectiveness of oral NAC (1 g orally twice daily [b.i.d.]) as an add-on to maintenance medication for the treatment of chronic schizophrenia over a 24-week period. METHODS: A randomized, multicenter, double-blind, placebo-controlled study. The primary readout was change from baseline on the Positive and Negative Symptoms Scale (PANSS) and its components. Secondary readouts included the Clinical Global Impression (CGI) Severity and Improvement scales, as well as general functioning and extrapyramidal rating scales. Changes following a 4-week treatment discontinuation were evaluated. One hundred forty people with chronic schizophrenia on maintenance antipsychotic medication were randomized; 84 completed treatment. RESULTS: Intent-to-treat analysis revealed that subjects treated with NAC improved more than placebo-treated subjects over the study period in PANSS total [-5.97 (-10.44, -1.51), p = .009], PANSS negative [mean difference -1.83 (95% confidence interval: -3.33, -.32), p = .018], and PANSS general [-2.79 (-5.38, -.20), p = .035], CGI-Severity (CGI-S) [-.26 (-.44, -.08), p = .004], and CGI-Improvement (CGI-I) [-.22 (-.41, -.03), p = .025] scores. No significant change on the PANSS positive subscale was seen. N-acetyl cysteine treatment also was associated with an improvement in akathisia (p = .022). Effect sizes at end point were consistent with moderate benefits. CONCLUSIONS: These data suggest that adjunctive NAC has potential as a safe and moderately effective augmentation strategy for chronic schizophrenia.

Evaluation of a short scale to assess female sexual functioning.

This article provides information on the external and concurrent validity, test-retest reliability, and sensitivity to change of a short form of the Personal Experiences Questionnaire, which was adapted from the McCoy Female Sexuality Questionnaire. We drew participants from convenience samples of women attending three different clinic settings: family planning clinics, psychiatrists, and sex therapists. We chose the psychiatry and sex therapy clinics as samples likely to show poor sexual functioning in order to assist with external validity assessment and to establish a cut-off score indicating sexual dysfunction. Satisfactory external criterion validity, concurrent validity, reliability on re-test, and validation of the composite score were demonstrated. A cut-off score of 7 or below distinguishes with 79% specificity and sensitivity those with sexual dysfunction.