Sleep, psychiatric and socioeconomic factors associated with substance use in a large population sample: A cross-sectional study.

Multiple elements modulate drug use, including sleep, which is increasingly being considered as an important contributor to substance use and abuse. The present study aimed to evaluate the association between sleep, psychiatric and socioeconomic/demographic factors and substance use in a large-scale representative sample from the city of São Paulo, Brazil. Data from the 2007 São Paulo Epidemiological Sleep Study (EPISONO) database were used. In the EPISONO study, volunteers underwent a polysomnographic exam and completed a series of questionnaires to assess objective and subjective sleep quality and associated comorbidities. Drug use was assessed using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). Linear (univariate and multivariate) and logistic regressions were performed to identify factors associated with the use of the 4 most commonly used substances in the sample (tobacco, alcohol, cannabis and cocaine/crack). Structural equation models were used to establish theoretical networks to explain the relationship between sleep, psychiatric and socioeconomic factors and use of these substances. The logistic regression results showed that psychiatric symptoms, lower income, and poorer subjective sleep were the main factors associated with tobacco consumption; gender and occupational status with alcohol intake; age and occupation with cannabis use; and education with cocaine/crack use. The structural equation models partially supported these findings and identified significant effects of psychiatric symptoms on tobacco consumption, both directly and mediated by sleep. Our results reinforce previous findings concerning factors associated with generally misused substances and suggest that sleep should be considered as an important element in future substance use disorder studies.