To evaluate diurnal preference and sleep patterns in relation to alcohol consumption.

The Alcohol Use Disorders Identification Test (AUDIT), the Sleep Disorders Questionnaire, the Pittsburgh Sleep Quality Index, the Pittsburgh Insomnia Rating Scale, the Multidimensional Fatigue Inventory, the Epworth Sleepiness Scale, the Beck Depression Inventory II and the Composite Scale of Morningness (all in Romanian translation) were used. Subjects, aged over 18, were recruited from the Psychiatric facilities of the Baia Mare County Hospital, Romania, as well as from patients’ families or acquaintances and from students attending the Faculty of Psychology in Cluj-Napoca. We excluded people suffering from certain conditions that impair sleep (e.g. sleep apnoea).

Three hundred and six people (age: 41.2±15.7) were included in this study. Based on AUDIT scores, we created three groups (low, medium and high alcohol use). We found that alcohol consumption influenced sleep and sleep quality: the higher the alcohol consumption was, the more disrupted the sleep and the more severe the sleep loss consequences (fatigue, daytime sleepiness, depression) were. About a half of the high alcohol consumers (48.5%) experienced insomnia, lasting more than a month and impairing their functionality (compared to 18% of the low consumers and 25% of the medium consumers; X=19.5, P=0.001). Individuals with evening or morning preference and moderate or high alcohol use tended to score higher in the AUDIT compared to those of intermediate preference.

These results indicate that alcohol consumption is linked with sleep disturbances and that diurnal preference may also influence alcohol intake.