 In choosing pharmacological treatment for a high risk group, there is the possibility of causing harm with antidepressants if the true diagnosis is bipolar disorder, and of not treating the depression adequately if using mood stabilizers in what is truly a unipolar illness. This dilemma applies to a large subgroup of those presenting with depression. A recent study in a primary care setting suggested that as many as 21 of patients currently treated with antidepressants for a presumed depressive disorder may in fact have a bipolar diathesis, thus representing a large group that may be improperly treated9. 