The influence of comorbid personality disorder on patients in heroin-assisted treatment: Pilot data on clinical outcome

Background: The diagnosis of a comorbid personality disorder (PD) is very common in patients with drug dependence. However, it is unclear whether differences between opioid-dependent patients with and without co-occurring PD influence diamorphine-assisted substance abuse treatments. Methods: Twenty-six patients with a diagnosis of opioid dependence (according to DSM-IV) in a stable heroin-assisted treatment (HAT) were included in this pilot study. The SCID II was used to assess the personality disorder diagnosis. At baseline, history of substance abuse (ASI), depressive symptoms (BDI) and childhood trauma (CTQ) were measured. At a 12-month follow-up, the clinical course was assessed with the Opiate Treatment Index (OTI), and substance abuse as well as depressive symptoms were newly assessed. Results: Fifty percent (n = 13) of the patients were diagnosed with at least one personality disorder. Patients with co-occurring PD experienced more depressive symptoms at baseline (p <0.05), were more traumatized (p <0.01) but had a shorter treatment history of heroin-assisted treatment (p <0.05) and less cannabis abuse (p<0.05) than those without a PD. At the 12-month follow-up, patients with comorbid PD showed worse overall psychological adjustment (p <0.01). Conclusion: Patients with co-occurring PD had more severe psychopathological symptoms. These findings indicate that even within a heroinassisted treatment group, patients with opioid dependence suffering from an additional PD may represent a sicker clinical subgroup, which could benefit from disorder-specific treatment.