Non-lethal self-injury represents a behaviour disorder which has insufficiently been analyzed systematically. Along with self-inflicting superficial wounds, ingesting substances, especially drugs, it is the most frequent method of realizing these autolitic acts.

The aim of the research was to establish the socio-demographic characters of this category vulnerable to substances abuse and to establish the differences with males from the general population who realized the same kind of self-injury and the behaviour differences along the therapeutic act.

The study was carried on a group of 48 inmates (all males) who realized non-lethal autolitic acts through substances abuse (01.01–12.31.2009). The group was compared with another group of men from the general population who realized the same kind of self-harm using the same methods, during the same period of time (N = 179). The data has been analyzed using SPSS 17.0, frequency analysis, descriptive and cross-sectional analysis, average comparison tests, non-parametric tests.

The inmates’ average age was 10 years lower. They have realized the self-injury especially on Fridays and in the afternoons, the others on Saturdays and in the mornings. The inmates had less psychiatric antecedents, they haven’t associated the act with alcohol, and they have accepted the treatment and the hospitalization more often, due to their penitentiary conditions.

There are significant differences between the inmates with substances abuse compared to the group from the general population. The motivation is different for the two groups, the medical intervention and counselling that follows are more systematically done in penitentiary.