Insomnia and tobacco use are frequent and important problems in alcohol-dependent patients. However, the relationship between sleep problems and cigarette smoking was not thoroughly investigated in this population.

The purpose of the study was to investigate the relationship between tobacco smoking and severity of insomnia in alcohol-dependent patients in treatment. We also aimed at assessing other predictors of insomnia in this population.

The study group comprised 384 alcohol-dependent patients. Standardized tools were used to assess: tobacco dependence (Fagerström Test for Nicotine Dependence [FTND]), sleep problems (Athens Insomnia Scale [AIS]), severity of alcohol dependence (Michigan Alcohol Screening Test [MAST]) and drinking quantities before entering treatment (Timeline Follow Back [TFLB]). Other comorbid psychiatric symptoms were assessed using Brief Symptom Inventory (BSI) and Barratt's Impulsiveness Scale (BIS-11).

The study group included 79.1% of current smokers, 62% of participants reported insomnia (AIS). The mean FTND score was 6.05 ± 2.18. The multivariate regression analysis revealed that the severity of tobacco dependence was significantly associated with the severity of insomnia (FTND, beta = 0.140, P = 0.013). Other factors associated with insomnia that remained significant in multivariate model were severity of psychopathological symptoms (BSI, beta = 0.422, P < 0.0005) and intensity of drinking (TLFB, beta = 0.123, P = 0.034).

Tobacco use may predict severity of insomnia in alcohol-dependent patients. This finding may have important clinical implications and influence strategies applied in treatment of alcohol use disorders.

The authors have not supplied their declaration of competing interest.