The role of personality disorder in 'difficult to reach' patients with depression: findings from the ODIN study.

Individuals with personality disorders (especially paranoid personality disorder) tend to be reluctant to engage in treatment. This paper aimed to elucidate the role of personality disorder in predicting engagement with psychological treatment for depression. The Outcomes of Depression International Network (ODIN) involves six urban and three rural study sites throughout Europe at which cases of depression were identified through a two-stage community survey. One patient in seven who was offered psychological treatment for depression had a comorbid diagnosis of personality disorder (most commonly paranoid personality disorder). Forty-five percent of patients who were offered psychological treatment for depression did not complete treatment. The odds of completion were higher for patients with a comorbid diagnosis of personality disorder, especially paranoid, anxious or dependent personality disorder. The relatively low number of cases with some specific personality disorders (e.g. schizoid personality disorder) limited the study's power to reach conclusions about these specific disorders. This study focused on a community-based sample which may lead to apparently lower rates of engagement when compared to studies based on treatment-seeking populations. Episodes of depression in the context of personality disorder may represent a valuable opportunity to engage with patients who might otherwise resist engagement.