Depressive mixed state frequency: age/gender effects.

Depressive mixed state (DMX), a major depressive episode (MDE) combined with few manic/hypomanic symptoms, is understudied. Age and gender are important variables in mood disorders. The aim of the present study was to determine whether age and gender had any effect on the frequency of DMX. Consecutive unipolar (n = 144) and bipolar II (n = 218) drug-free MDE out-patients were interviewed with the Structured Clinical Interview for DSM-IV when presenting for MDE treatment. The presence of hypomanic symptoms during the index MDE was assessed systematically. Depressive mixed state was defined as a MDE with three or more concurrent hypomanic symptoms (DMX3), following previous reports. Associations were tested by logistic regression. The results showed that the DMX3 frequency was 43.9% and that it affected more females than males. Frequency decreased with age. The lower frequency with age was related to the lower frequency of bipolar II disorder with age. Bipolar disorder family history of DMX3 patients did not change with age. In conclusion, the frequency of DMX3 was high and related to age. The high frequency of DMX3 supports the clinical usefulness of the definition, as well as observations that antidepressants may worsen its hypomanic symptoms, whereas antipsychotics and mood stabilisers may treat them. A bipolar vulnerability seems to be required for the appearance of DMX3 also in later life.