Personality disorders in addiction outpatients: prevalence and effects on psychosocial functioning.

Aim: To evaluate the prevalence of personality disorders (PDs) in the outpatients attending an addiction service, with particular attention to the effects of PDs on social and occupational functioning and on the intensity of treatment required.

Design: A cross-sectional epidemiological study with the assessment of 320 outpatients, through SCID-II (Structured Clinical Interview for DSM-IV Axis II PDs), SOGS (South Oaks Gambling Screen), and questionnaire extracted from EuropASI.

Results: The percentage prevalence of PDs was 62.2% (confidence interval at 95% (95% CI): 57-68). PDs were positively associated with placement in an addiction treatment community (odds ratio (OR) = 2.98, CI = 1.77-5.03), having received lifetime treatment at the mental health center (MHC) (OR = 3.67, CI = 1.67-8.07) or having attempted suicide (OR = 2.30, CI = 1.05-5.02). Furthermore, PDs were related to a reduced probability of keeping a job (OR = 0.54, CI = 0.31-0.95) or starting a family (OR = 0.51, CI = 0.30-0.87).

Conclusion: Axis II comorbidity occurs in 62% of addiction outpatients and has substantial effects on social and occupational functioning as well as on treatment programs.