Background: This paper examines the prevalence of psychotropic substance (tobacco, alcohol, narcotic drugs) use among inmates of Lithuanian prisons and the association between drug use and psychosocial factors.
Material/Methods: The questionnaire used was based on the ESPAD questionnaire, modifi ed to fi t the specifi c respondent group. At the time of the study there were 9634 inmates in Lithuanian penal institutions; 1304 of them participated in the study, 67 (5.2%) were women, 115 (8.8%) boy minors, and 1122 (86%) men. Statistical analysis was carried out using EpilInfo 6.04.
Results: It was revealed that 48.7% of the prisoners had used drugs at least once in their lives, 13.8% of prisoners currently used narcotic drugs, and 39.8% had fi rst used illicit (narcotic) drugs in prison.
85.3% currently smoked tobacco and 92.1% had drunk alcohol at least once in their lives.
Conclusions: Psychotropic substances are often used due to their psychological impact. Imprisoned people constitute a high-risk group of drug users and distributors of narcotic drugs. Consequently, the problem of psychotropic substance addiction in penal institutions awakens more concern than the same problem in the general society. Intravenous narcotic drugs stimulating dangerous behavior are prevalent in Lithuanian prisons.

Keywords: Adolescent, Lithuania - epidemiology, Prevalence, Prisons, Psychotropic Drugs - pharmacology, Smoking, Substance-Related Disorders - epidemiology