Does abstinence resolve poor sleep quality in former methamphetamine dependents?

Background and objective: Among substances that have a significant effect on sleep are stimulants, including amphetamines. As there are few studies assessing sleep quality in methamphetamine withdrawal this study aims to evaluate changes in sleep quality of methamphetamine dependent patients during early remission period by controlling depression and anxiety as confounding variables. Methods: This study was conducted in Mashhad, Iran. Ninety amphetamine dependent patients, who were admitted in residential centers during 2012-2014 and met our inclusion criteria, were chosen by purposive nonprobability sampling method. Sleep quality was assessed by Pittsburg sleep questionnaire, in the first, second, and after the fourth week of abstinence. Additionally all participants were assessed by Beck Depression Inventory-2 and Beck Anxiety Inventory for controlling depressive and anxiety symptoms. Results: The prevalence of improper quality of sleep was very high (97.8%) within the first week of withdrawal, but it reduced considerably four weeks after abstinence (52.2%), which was statistically significant (P=0.00). The variations of depression and anxiety levels within four weeks after quitting methamphetamine, have low impact on variation of patients' sleep quality (adjusted R2 < 0.5). Furthermore, the effectiveness of these two intervening variables on patients' quality of sleep was dwindled over time after abstinence. Conclusions: This study showed that the patients' quality of sleep improved significantly four weeks after abstinence and its variation was independent from variations in anxiety and depressive symptoms.