Objectives:
Sleep disorders in the form of insomnia or excessive daytime sleepiness have their health and social consequences. The aim of the study was to evaluate the frequency of sleep disorders, quality of life and the pattern of psychoactive substance use among the students of Polish universities using CAVI method.

Methods:
The Athens Insomnia Scale, the Epworth Sleepiness Scale, and the Manchester Short Assessment of Quality of Life were used. The study was conducted using anonymous and voluntary questionnaires distributed via the Internet.

Results:
Most of the respondents (N = 5,342) were women (74%). A high percentage (>51%) of sleep disorders was found in women. Daytime sleepiness occurred in 28% of respondents, which correlated with sleep disorders. The use of psychoactive drugs is very common (94%) among Polish students of both sexes and (apart from alcohol) significantly affects the quality of life (p = 0.000). In the assessment of the psychoactive substance use pattern, the students of medical universities only slightly differ from students of other majors. The quality of life of people affected by sleep disorders is much lower than of the healthy student population.

Conclusions:
The great scale of the sleep disorder phenomenon and the use of psychoactive substances among Polish students require further exploration with particular emphasis on preventive and therapeutic activities.