RESUMO
BACKGROUND: The relation between impulsivity and sleep indices is not well determined in patients receiving methadone maintenance treatment (MMT). AIMS: to evaluate high impulsivity prevalence, its risk factors and relation with sleep indices. METHODS: a random MMT sample (n = 61) plus MMT current cocaine users (n = 20) were assessed for impulsivity (Barratt impulsivity scale [BIS-11] and Balloon Analogue Risk task [BART]), sleep quality (Pittsburg Sleep Quality Index [PSQI]), sleepiness (The Epworth sleepiness scale [ESS]), and substance in urine. RESULTS: 81 patients, aged 56.6 ± 10, 54.3% tested positive to any substance, 53.1% with poor sleep (PSQI>5) and 43.2% with daytime sleepiness (ESS >7) were studied. Impulsivity (BIS-11 ≥ 72) prevalence was 27.9% (of the representative sample), and 30.9% of all participants. These patients characterized with any substance and shorter duration in MMT with no sleep indices or other differences including BART balloon task performance (that was higher only in any substance than non-substance user group). However, impulsive score linearly correlated with daytime sleepiness (R = 0.2, p = 0.05). Impulsivity proportion was lowest among those with no cocaine followed by cocaine use and the highest in those who used cocaine and opiates (20.8%, 33.3% and 60% respectively, p = 0.02), as daily sleep (38.3%, 42.1% and 60%, p = 0.3) although not statistically significant. CONCLUSION: Daytime sleepiness correlated with impulsivity, but cocaine usage is the robust factor. Further follow-up is warranted to determine whether substance discontinuing will lead to a reduction in impulsivity, and improved vigilance. Sleep quality did not relate to daytime sleepiness and impulsivity and need further research.
