The Clinical Features of Bipolar Depression

Letter to the Editor

Sir: In the article by Mitchell et al. on bipolar depression, in which they compared the major depressive episodes (MDEs) of bipolar I disorder and major depressive disorder (MDD) inpatients and outpatients matched for gender and age, bipolar I patients had significantly more psychomotor-retarded melancholic and atypical features. One atypical feature, hypersomnia, was present in 43.6% of bipolar I versus 18.0% of MDD patients, and bipolar I patients had significantly more psychomotor retardation (71.8% vs. 41.0%). The authors made reference to an article of mine, suggesting that my comparison of MDE in bipolar II versus MDD patients should have been controlled for age.