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

Abstract

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. K E Y W O R D S bipolar-I disorder, comorbidity, epidemiology, family history, gender, mania How to cite this article: Angst J, Rössler W, Ajdacic-Gross V, et al. Differences between unipolar mania and bipolar-I disorder: Evidence from nine epidemiological studies. Bipolar Disord. 2019;21:437-448. https://doi.

The 2020 Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders

“…The schematic shows the various ‘diagnostic categories’ (shown within a colour spectrum band) and also shows the two syndromes, mania and depression. Of note, both mania and depression can be present uniquely giving rise to unipolar mania and unipolar depressive disorder but can also occur together (shown overlapping) to create bipolar disorder (Angst et al, 2019). Critically, the schematic suggests that there is no meaningful distinction between the depressive symptoms in major depressive disorder and those seen as part of bipolar disorder, namely ‘bipolar depression’ and to date, this appears to be a valid interpretation.…”

The 2020 Royal Australian and New Zealand College of psychiatrists clinical practice guidelines for mood disorders: Bipolar disorder summary

“…13 But recently, there has been greater interest in dimensional approaches to classification, and, informed by empirical studies and clinical experience, alternative schema and cut-offs for putative bipolar syndromes have been proposed. [14][15][16]…”

Pharmacotherapeutic interventions for bipolar disorder type II: addressing multiple symptoms and approaches with a particular emphasis on strategies in lower and middle-income countries

“…According to DSM-5, BP-I represents a classic manic depressive disorder although neither a depressive episode nor psychosis needs to be present for diagnosis [72]. However, there is ongoing controversy whether unipolar mania should be a seperate diagnosis from BD-I [73]. BP-II (Bipolar II) is characterized by less severe manic symptoms, classified as hypomania, however combined with depressive episodes [69,70,74].…”