Bipolar mood disorders among Polish psychiatric outpatients treated for major depression

Significant proportion of patients treated for depression may have various types of bipolar mood disorders. The aim of the study was to assess the frequency of bipolar disorders among outpatients having at least one major depressive episode, treated by 96 psychiatrists, representing all regions of Poland.

The study included 880 patients (237 male, 643 female), identified to following diagnostic categories: bipolar I, bipolar II, bipolar spectrum disorder and major depressive disorder.

Bipolar mood disorders were found in 61.2% of patients studied, bipolar I more frequent in men and bipolar II in women, and bipolar spectrum in 12% of patients. Patients with age ranges 19-49 and 50-65 years did not differ as to the percentage of diagnostic categories. Patients with bipolar mood disorders compared to major depressive disorder had significantly more frequent family history of bipolar disorder, premorbid hyper- or cyclothymic personality, early onset of depression, symptoms of hypersomnia and hyperphagia, psychotic depression, post-partum depression, and treatment-resistant depression. Bipolar spectrum patients had most clinical features similar to classic types of bipolar disorders.

Neither structured interview for family history, nor formal criteria for a number of clinical manifestations were used. The population treated by psychiatrists may not be representative and present a subgroup with more severe mood disorders.

Bipolar mood disorders may be very prevalent among depressive outpatients treated by psychiatrists in Poland, which is confirmed by the results of recent studies. Bipolar patients (including bipolar spectrum) significantly differ from major depressive disorder as to numerous clinical features related mostly to depressive episode.