Abstract
The paper presents the study on identification and systematic description of typical behavioral patterns of drug usage. The dataset is based on the qualitative interviews with 70 drug users and the survey within 80 experts of federal drug control service in St. Petersburg obtained in the course of 2015. A behavioural pattern is considered as a sequence of typical states occurring during the deviation career of a drug user described by certain psych o-physiological characteristics. It is argued that the transitions between these states are not always linearly determined, but rather depend upon desires and motivations of the drug user, which in turn depend on a variety of personal, environmental, and social factors. Based on the empirical data we define basic states and probabilities of transitions between them. Then we build an information model of basic algorithms of narcotization process which can be used for forecasting drug addiction.