Non-completion of personality disorder treatments: a systematic review of correlates, consequences, and interventions.

Non-completion of treatment is a major concern in the provision of therapies for people diagnosed with personality disorder, with adverse consequences for services, therapists, and other patients. Of even greater concern is that non-completion of treatment may limit the effectiveness of therapy for individuals. Our main aim in this study was to conduct a systematic review of the literature on psychosocial treatments for personality disorder to identify factors associated with treatment non-completion. Two subsidiary aims were to identify studies that reported the relative outcomes of treatment completion and non-completion, and to identify studies that evaluated psychosocial interventions specifically aimed at improving retention in treatment. This information is potentially useful in informing selection criteria and directing efforts towards improving treatment engagement. Twenty-five empirical studies of factors predicting treatment non-completion were identified. The median non-completion rate was 37%. A range of patient characteristics, need factors, and environment factors were identified as associated with non-completion. However, the studies could not be considered homogeneous group for meta-analysis. Four studies investigated the effects of treatment non-completion, showing an association with adverse outcomes. Only two studies of interventions specifically aimed at reducing non-completion were identified. Implications for clinical practice and research are discussed.