Drug use is one of the challenges the humanity faces, its direct or indirect effects revealing a fearful phenomenon, worthy of being an important subject in international cooperation programs. The existence of this context is the reason we have set our minds on doing such a research with the purpose of contributing to knowing the psychological causes of the addiction phenomenon starting with the hypothesis of an existing pattern of personality (which is found in a certain context) that facilitates the „fall“ of an individual into the drug trap. The general objective consists in the evidentiation (shaping) of a certain personality structure as a result of the summation of traits that determine and favorises the drug use. Instruments used: Within the study we have used as research methods the following psychological tests: 16 PF, STAIX 1, The hostility test. The research was carried out on teenagers within the age limits 18-24 years. Actually there were 2 different batches (a control batch and an experimental one) with a total of 60 people. Conclusions. Following the analysis and interpretation of the results we can conclude that the two hypothesis were confirmed. The study confirms that all drug users have an emphasis of the personality traits mainly emotional instability with rapid shifting from a disposition to another. The results show that in drug addicted teenagers there are some patterns of reaction to the stimulation of social environment. These patterns are based on emotional instability, fragility of the personality structures and impulsivity, being in close correlation with an insufficient knowledge and self-restrain of the emotional reactivity.