The UK National Institute of Clinical Excellence published revised guidance on the assessment and management of Bipolar Affective Disorder (or just `Bipolar Disorder`) in September last year. This is a condition which involves both episodes of depression and episodes of mania. Bipolar depression requires different treatment strategies than unipolar depression. The guidance also lays out recommendations around relapse prevention.
I think it is well worth a read as it marks a departure from traditional practice in the treatment of Bipolar Depression in particular, bringing the guidance up to date with the most recent evidence.