Personality disorders in a clinical sample of Cannabis dependent young adults

INTRODUCTION: Cannabis addiction with comorbid personality disorders (PDs) is associated with a heavier individual burden of disease. Most previous studies focussed on singular disorders like borderline or antisocial PD, there is little data available on the full range of PD. Even less is known about the prevalence of PD with cannabis addiction in inpatient settings. The aim of this study is to investigate the frequency of PD and their relevance in treatment of young adult Cannabis-dependent inpatients. METHODS: 99 adolescents and young adults diagnosed with Cannabis dependence according to DSM I, were investigated during their detoxification treatment in an addiction treatment ward. Personality disorders were assessed using the SCID II questionnaire. RESULTS: The intensity of personality disorder traits was high in this inpatient sample. The probands showed a higher burden of disease from PDs other than the antisocial and Borderline PDs previously reported. Almost 90% of the subjects received the diagnosis of an antisocial PD, more than half had a paranoid and more than a third suffers from a Borderline PD. More than 35% of the sample had more than three PDs. There were no consistent relationships between PDs and concurrent consumption of other drugs, severity of drug addiction or delinquency. CONCLUSION: There is evidence of PDs in almost all inpatient Cannabis-dependent adolescents and young adults. Diagnosis and treatment of these subjects has to provide not only addiction-specific approaches but also strategies to improve dysfunctional behaviour caused by personality disorder characteristics.