Objective: Aggression is a particular problem commonly observed in personality disorders, especially in antisocial personality disorder (APD). It is well known that APD is closely related to substance use disorder (SUD). Individuals with higher aggression levels have also been suggested to have higher rates of SUD. The aim of this study is to investigate aggression levels and substance use characteristics of APD subjects with and without violent criminal behavior.

Method: A total of 124 male subjects with APD consecutively admitted to the Forensic Psychiatry Department of GATA Haydarpasa Training Hospital were involved in the study. All subjects were evaluated with an assessment battery using a semistructured interview for socio-demographic, APD, and substance use characteristics, APD section of SCID-II, SCID-I, and Aggression Questionnaire. The sample was divided into 2 groups in terms of having a history of violent criminal behavior and compared correspondingly.

Results: Of the APD subjects, 90.3 % reported a lifetime history of substance abuse and 75.8 % had a current co-diagnosis of SUD. APD subjects with violent criminal behavior were more likely to be diagnosed with SUD as compared to those with out violent crimes. Moreover, APD subjects with SUD had higher aggression levels than those without SUD.

Conclusion: Our results indicate that substance use may mediate the association between APD and aggression. Therefore, the treatment of substance abuse in APD subjects is an important target particularly for prevention of violent criminal behaviors.