Statement of the problem and the purpose of the article. The article presents the results of studying the social, personal and clinical characteristics of juvenile suspects, accused, and convicted persons suffering from alcohol and drug addiction. The characteristic features are analyzed of adolescents in conflict with the law, suffering from alcohol and drug addiction. An average psychological portrait of juvenile suspects, accused, and convicted persons suffering from substance addiction is presented. The necessity to study the problem of the formation of alcohol and drug addiction in penitentiary institutions, factors contributing to the formation of addictive behavior in order to identify adolescents at risk is substantiated. The materials are of interest to prison psychologists, psychologists of educational institutions, and representatives of the system of prevention of child neglect and juvenile delinquency. Materials and methods of research. The methodological and theoretical basis of the undertaken research includes systemic (B.F. Lomov), complex (B.G. Ananyev), activity-based (S.L. Rubinstein) and personality-oriented (K.A. Abulkhanova-Slavskaya, A.G. Asmolov, A.A. Bodalev, A.V. Petrovsky, K. Rogers, A. Maslow) approaches; the concept of formation of child’s personality and self-consciousness (V.S. Mukhina, V.V. Stolin, etc.); the concept on the influence of activity and communication on the ontogenesis of children (L.S. Vygotsky, A.Ya. Varga, A.N. Leontiev, M.I. Lisina, A.S. Spivakovskaya, D.B. Elkonin, etc.). The study used a questionnaire survey to identify socio-demographic (intra-family relationships, social role, education, behavior before conviction), criminological (information from the Minors Affairs Department, type of crimes), medical characteristics and to identify the causes of alcohol and drug addiction in minors. There was also a study of the personality characteristics of juvenile suspects, accused, and convicted according to the following methods: Kettell’s method of multifactorial research of personality (form C), the abbreviated Mini-Cartoon test (SMIL), the Shmishek questionnaire (children’s version). Research results. The prerequisites are determined for early initiation into the use of alcoholic and narcotic substances, as well as criminalization of adolescents in conflict with the law in the territorial bodies of the Siberian Federal District. An average psychological portrait of juvenile suspects, accused, and convicted persons suffering from alcohol and drug addiction is presented. The necessity of studying the problem of the formation of alcohol and drug addiction in penitentiary institutions, factors contributing to the formation of addictive behavior in order to identify adolescents at risk is substantiated. Conclusion. Juvenile suspects, accused, and convicted persons suffering from alcohol and drug addiction have similar features in many ways, which allows us to present their average psychological portrait. Teenagers have a craving for communication, being part of significant groups, but communication is superficial, there may be a lack of a sense of distance in relationships with others. Below average level of verbal intelligence, narrow outlook. They tend to combine accentuations of hyperthymic, emotive types, with signs of cyclothymia. The reaction of emancipation is expressed, the orientation of attitudes towards self-affirmation, the desire for pleasure and the dominance of one’s own interests and desires. Inadequate self-esteem, high level of pretensions. Outbursts of anger and irritation are characteristic, especially when they meet strong opposition and fail. They are not taking their responsibilities seriously enough. Teenagers are characterized by instability of character, mood variability, which is difficult to predict. Juvenile suspects, accused, and convicted persons suffering from drug addiction also have signs of excitable, demonstrative, exalted types (Shmishek), which complements their psychological portrait with such qualities as impulsivity, impetuosity, short temper, quarrelsome in a team, a tendency to rudeness, fantasy, deceit, pretense, indifference to the future, increased impressionability, lability, but at the same time the ability to repress is expressed; the need for recognition, attention, sympathy; egocentrism.