2083 – Prevalence of unipolar mania and evaluation of the characteristics in unipolar and bipolar mania in kerman (Iran)

Differences between unipolar mania and bipolar-I disorder: Evidence from nine epidemiological studies

OBJECTIVES

Although clinical evidence suggests important differences between unipolar mania and bipolar-I disorder (BP-I), epidemiological data are limited. Combining data from nine population-based studies, we compared subjects with mania (M) or mania with mild depression (Md) to those with BP-I with both manic and depressive episodes with respect to demographic and clinical characteristics in order to highlight differences.

METHODS

Participants were compared for gender, age, age at onset of mania, psychiatric comorbidity, temperament, and family history of mental disorders. Generalized linear mixed models with adjustment for sex and age as well as for each study source were applied. Analyses were performed for the pooled adult and adolescent samples, separately.

RESULTS

Within the included cohorts, 109 adults and 195 adolescents were diagnosed with M/Md and 323 adults and 182 adolescents with BP-I. In both adult and adolescent samples, there was a male preponderance in M/Md, whereas lifetime generalized anxiety and/panic disorders and suicide attempts were less common in M/Md than in BP-I. Furthermore, adults with mania revealed bulimia/binge eating and drug use disorders less frequently than those with BP-I.

CONCLUSIONS

The significant differences found in gender and comorbidity between mania and BP-I suggest that unipolar mania, despite its low prevalence, should be established as a separate diagnosis both for clinical and research purposes. In clinical settings, the rarer occurrence of suicide attempts, anxiety, and drug use disorders among individuals with unipolar mania may facilitate successful treatment of the disorder and lead to a more favorable course than that of BP-I disorder.

Will mania survive DSM-5 and ICD-11?

As a natural phenomenon, mania without major depression will of course survive DSM-5 and ICD-11, but following its integration as a diagnosis into bipolar-I disorder (BP-I) in those manuals, BP-I will be more heterogeneous and, paradoxically, will include a unipolar disorder. Furthermore, unipolar mania will no longer be adequately identified and coded as an independent disorder in public health statistics. Mania without major depression, with prevalence rates of 1.7-1.8 %, is even more common than schizophrenia. This brief review of our current, still insufficient, knowledge suggests strongly that pure unipolar mania, as well as mania with minor depressive disorders, should remain important elements of the three-dimensional mood spectrum. Research should focus on dimensional and not on simplified categorical models, which entail a considerable loss of information.

Unipolar mania: a necessary diagnostic concept

In the classification of mood disorders, major depressive disorder is separate from bipolar disorders whereas mania is not. Studies on pure mania are therefore rare. Our paper reviews the evidence for distinguishing pure mania (M) and mania with mild depression (Md) from bipolar disorder. Two large epidemiological studies found a prevalence of 1.7-1.8% of M/Md in adolescents and adults. Several clinical follow-up studies demonstrated good stability of the diagnosis after a previous history of three manic episodes. Compared to bipolar disorder, manic disorder is characterised by a weaker family history for depression, an earlier onset, fewer recurrences and better remission, and is less comorbid with anxiety disorders. In addition, mania is strongly associated with a hyperthymic temperament, manifests more psychotic symptoms and is more often treated with antipsychotics. Twin and family studies find mania to be more heritable than depression and show no significant transmission from depression to mania or from mania to depression. Cardiovascular mortality is elevated among patients with mood disorders generally and is highest among those with mania. In non-Western countries, mania and the manic episodes in bipolar disorder are reported to occur more frequently than in Western countries.