A preliminary evaluation of the effectiveness of dialectical behaviour therapy in a forensic psychiatric setting.

Dialectical behaviour therapy (DBT) is a therapy model incorporating elements of Eastern philosophies and cognitive behavioural principles. Originally designed for people struggling with chronic suicidality and borderline personality disorder (BPD), it has been adapted to treat complex, multi-diagnostic presentations, such as those in forensic mental health settings. To date, there has been little evaluation when the primary diagnosis is of psychosis. To explore the effectiveness of DBT, with patients, with multiple comorbidities, including psychosis, in a forensic psychiatric inpatient setting. A descriptive outcome study with a cohort of offender-patients in one specialist forensic mental health unit. Before and after treatment change scores were compared on anger, aggression, hopefulness, coping abilities, emotional intelligence, insight and subjective symptom severity scales, as well as staff-rated risk, and length of stay. Nine men and five women residents in one Canadian secure hospital completed a standard DBT programme, and self-ratings, over about 1 year. Scale scores indicated significantly increased insight and acknowledgment of problems. Apparently increased anger and vengeance scores were clinically associated. Independent staff ratings indicated reductions in risk and most patients achieved early release. This study provides support for extension of the use of DBT to offender-patients with psychosis among the complex mix in their presentation. It suggests that a randomised controlled trial with cost-benefit analysis is warranted, as well as further work, to promote understanding of mechanisms of effectiveness.