Bipolar disorder is a chronic mental illness which causes severe problems for sufferers. Treatment is usually with medications which have side effects. Psychotherapies are very helpful, but are not available in most public health services, because it is perceived that they are expensive and impractical. In partnership with Canterbury District Health Board, we will trial a specific therapy for bipolar disorder, in routine clinical practice. Social Rhythms Therapy will be introduced into the practice of half of the clinical teams treating bipolar disorder. The outcomes for patients in these teams will be compared with those of patients treated by teams who do not practice the therapy. Before starting the full trial we need to show that the clinicians involved can be adequately trained and can practice the psychotherapy well. The results have the potential to change usual treatment for bipolar disorder in New Zealand and Internationally.