Bipolar affective disorder is a serious mental illness with significant mortality and morbidity [1]. Some estimates of prevalence in Western populations are as high as 6.4% [2]. The depressive aspect of bipolar disorder is often overlooked, possibly due to its less dramatic nature, despite its significant impact on the lives of those who suffer from it [3]. Bipolar depression is associated with a twenty fold increased risk of suicide [4], and typically lasts three to five times as long as a manic or hypomanic episode [5, 6].