The identification of unipolar mania subtype based on anxiety comorbidity

Characterizing the clinical profile of mania without major depressive episodes: a systematic review and meta-analysis of factors associated with unipolar mania

BACKGROUND

The diagnostic concept of unipolar mania (UM), i.e. the lifetime occurrence of mania without major depressive episodes, remains a topic of debate despite the evidence accumulated in the last few years. We carried out a systematic review and meta-analysis of observational studies testing factors associated with UM as compared to bipolar disorder with a manic-depressive course (md-BD).

METHODS

Studies indexed up to July 2022 in main electronic databases were searched. Random-effects meta-analyses of the association between UM and relevant correlates yielded odds ratio (OR) or standardized mean difference (SMD), with 95% confidence intervals (CIs).

RESULTS

Based on data from 21 studies, factors positively or negatively associated with UM, as compared to md-BD, were: male gender (OR 1.47; 95% CI 1.11-1.94); age at onset (SMD -0.25; 95% CI -0.46 to -0.04); number of hospitalizations (SMD 0.53; 95% CI 0.21-0.84); family history of depression (OR 0.55; 95% CI 0.36-0.85); suicide attempts (OR 0.25; 95% CI 0.19-0.34); comorbid anxiety disorders (OR 0.35; 95% CI 0.26-0.49); psychotic features (OR 2.16; 95% CI 1.55-3.00); hyperthymic temperament (OR 1.99; 95% CI 1.17-3.40). The quality of evidence for the association with previous suicide attempts was high, moderate for anxiety disorders and psychotic features, and low or very low for other correlates.

CONCLUSIONS

Despite the heterogeneous quality of evidence, this work supports the hypothesis that UM might represent a distinctive diagnostic construct, with peculiar clinical correlates. Additional research is needed to better differentiate UM in the context of affective disorders, favouring personalized care approaches.

Characterization of clinical features and comorbidities between bipolar affective disorder with and without depressive episodes

BACKGROUNDS

A proportion of patients with bipolar disorder (BD) manifests with only unipolar mania (UM). This study examined relevant clinical features and psychosocial characteristics in UM compared with depressive-manic (D-M) subgroups. Moreover, comorbidity patterns of physical conditions and psychiatric disorders were evaluated between the UM and D-M groups.

METHODS

This clinical retrospective study (N = 1015) analyzed cases with an average of 10 years of illness duration and a nationwide population-based cohort (N = 8343) followed up for 10 years in the Taiwanese population. UM was defined as patients who did not experience depressive episodes and were not prescribed adequate antidepressant treatment during the disease course of BD. Logistic regression models adjusted for relevant covariates were used to evaluate the characteristics and lifetime comorbidities in the two groups.

RESULTS

The proportion of UM ranged from 12.91% to 14.87% in the two datasets. Compared with the D-M group, the UM group had more psychotic symptoms, fewer suicidal behaviors, a higher proportion of morningness chronotype, better sleep quality, higher extraversion, lower neuroticism, and less harm avoidance personality traits. Substantially different lifetime comorbidity patterns were observed between the two groups.

CONCLUSIONS

Patients with UM exhibited distinct clinical and psychosocial features compared with patients with the D-M subtype. In particular, a higher risk of comorbid cardiovascular diseases and anxiety disorders is apparent in patients with D-M. Further studies are warranted to investigate the underlying mechanisms for diverse presentations in subgroups of BDs.

The nosological status of unipolar mania and hypomania within UK Biobank according to objective and subjective measures of diurnal rest and activity

BACKGROUND

There is uncertainty whether unipolar mania is a discrete sub-type of bipolar disorder. Disrupted rest/activity rhythms are a key feature of bipolar disorder (BD) but have not been well characterised in unipolar mania/hypomania (UM). We compared subjective and objective rest/activity patterns, demographic and mental health outcomes across BD, UM and control groups.

METHODS

UK residents aged 37-73 years were recruited into UK Biobank from 2006 to 2010. BD, UM and control groups were identified via a mental health questionnaire. Demographic, mental health and subjective sleep outcomes were self-reported. Accelerometery data were available for a subset of participants, and objective measures of sleep and activity were derived.

RESULTS

A greater proportion of males met UM criteria, and more females were in the BD group. Both BD and UM groups had poor mental health outcomes vs. controls. Objectively measured activity differed between all three groups: UM had highest levels of activity and BD lowest. The UM group had shorter sleep duration compared to controls. Subjective rest/activity measures showed that both mood disorder groups (compared to controls) had later chronotype preference, more disturbed sleep and increased difficulty getting up in the morning. However, the UM group were more likely to report an early chronotype compared to BD and control groups.

CONCLUSIONS

BD and UM share features in common, but key differences support the proposition that UM may be a distinct and more clinically homogenous disorder. UM was characterised by a higher proportion of males, early chronotype, increased activity and shorter sleep duration.

Association of Polymorphism within the Putative miRNA Target Site in the 3'UTR Region of the DRD2 Gene with Neuroticism in Patients with Substance Use Disorder

The study aims at looking into associations between the polymorphism rs6276 that occurs in the putative miRNA target site in the 3'UTR region of the DRD2 gene in patients with substance use disorder (SUD) comorbid with a maniacal syndrome (SUD MANIA). In our study, we did not state any essential difference in DRD2 rs6276 genotype frequencies in the studied samples of SUD MANIA, SUD, and control subjects. A significant result was found for the SUD MANIA group vs. SUD vs. controls on the Neuroticism Scale of NEO FFI test, and DRD2 rs6276 (p = 0.0320) accounted for 1.7% of the variance. The G/G homozygous variants were linked with lower results on the neuroticism scale in the SUD MANIA group because G/G alleles may serve a protective role in the expression of neuroticism in patients with SUD MANIA. So far, there have been no data in the literature on the relationship between the miRSNP rs6276 region in the DRD2 gene and neuroticism (personal traits) in patients with a diagnosis of substance use disorder comorbid with the affective, maniacal type disturbances related to SUD. This is the first report on this topic.

Is unipolar mania a distinct entity: findings from the bipolar disorder course and outcome study from India (BiD-CoIN study)

AIM

This study aimed to evaluate the prevalence of unipolar mania (UM) in a group of patients of bipolar disorder (BD). Additionally, effort was made to evaluate the demographic, clinical and treatment related factors, which distinguish subjects of UM from BD.

METHODOLOGY

Seven hundred and seventy-three patients with BD, of at least 10 years duration, recruited from 14 General Hospital Units of tertiary care centers from India were evaluated for UM.

RESULTS

The prevalence of UM, varied from 5.4% to 20.3%, depending on the definition used. With the most stringent definition of ≥4 episodes of mania and at least 5 years of follow-up, the prevalence of UM was 5.4%. Compared to patients of BD, who have episodes other than mania too, those with UM had lower proportion of patients with lifetime history of suicide attempts, spent less time in the episodes in their lifetime and had lower severity of residual depressive and manic symptoms. Further, compared to those with episodes other than mania too, those with UM had higher number of manic episodes per year of illness, had higher proportion of patients who had more than five episodes in the lifetime and had higher proportion of those with at least one episode with psychotic symptoms in the lifetime.

CONCLUSION

The present study suggests that a small proportion of patients with BD have UM course and this runs a different clinical course compared to that seen in patients with traditionally recognized as BD.

Unipolar mania: Identification and characterisation of cases in France and the United Kingdom

BACKGROUND

Unipolar mania is a putative subtype of bipolar disorder (BD) in which individuals experience recurrent manic but not major depressive episodes. Few studies of unipolar mania have been conducted in developed countries and none in the UK. This study aimed to identify and characterise people with unipolar mania in the UK and France.

METHODS

People with unipolar mania were ascertained using a South London UK electronic case register and a French BD case series. Each unipolar mania group was compared to a matched group of people with BD who have experienced depressive episodes.

RESULTS

17 people with unipolar mania were identified in South London and 13 in France. The frequency of unipolar mania as a percentage of the BD clinical population was 1.2% for the South London cohort and 3.3% for the French cohort. In both cohorts, people with unipolar mania experienced more manic episodes than people with BD, and in the French cohort were more likely to experience a psychotic illness onset and more psychiatric admissions. Treatment and self-harm characteristics of people with unipolar mania were similar to people with BD.

LIMITATIONS

The relatively small number of people with unipolar mania identified by this study limits its power to detect differences in clinical variables.

CONCLUSIONS

People with unipolar mania can be identified in France and the UK, and they may experience a higher frequency of manic episodes but have similar treatment and self-harm characteristics as people with BD.

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.

Prevalence and Associated Features of Anxiety Disorder Comorbidity in Bipolar Disorder: A Meta-Analysis and Meta-Regression Study

Objective: Bipolar disorder is highly comorbid with anxiety disorders, however current and lifetime comorbidity patterns of each anxiety disorder and their associated features are not well studied. Here, we aimed to conduct a meta-analysis and meta-regression study of current evidence. Method: We searched PubMed to access relevant articles published until September 2015, using the keywords "Bipolar disorder" or "Affective Psychosis" or "manic depressive" separately with "generalized anxiety," "panic disorder," "social phobia," "obsessive compulsive," and "anxiety." Variables for associated features and prevalence of anxiety disorders were carefully extracted. Results: Lifetime any anxiety disorder comorbidity in BD was 40.5%; panic disorder (PD) 18.1%, generalized anxiety disorder (GAD) 13.3%, social anxiety disorder (SAD) 13.5% and obsessive compulsive disorder (OCD) 9.7%. Current any anxiety disorder comorbidity in BD is 38.2%; GAD is 15.2%, PD 13.3%, SAD 11.7%, and OCD 9.9%. When studies reporting data about comorbidities in BDI or BDII were analyzed separately, lifetime any anxiety disorder comorbidity in BDI and BDII were 38% and 34%, PD was 15% and 15%, GAD was 14% and 16.6%, SAD was 8% and 13%, OCD was 8% and 10%, respectively. Current any DSM anxiety disorder comorbidity in BDI or BDII were 31% and 37%, PD was 9% and 13%, GAD was 8% and 12%, SAD was 7% and 11%, and OCD was 8% and 7%, respectively. The percentage of manic patients and age of onset of BD tended to have a significant impact on anxiety disorders. Percentage of BD I patients significantly decreased the prevalence of panic disorder and social anxiety disorder. A higher rate of substance use disorder was associated with greater BD-SAD comorbidity. History of psychotic features significantly affected current PD and GAD. Conclusions: Anxiety disorder comorbidity is high in BD with somewhat lower rates in BDI vs BDII. Age of onset, substance use disorders, and percentage of patients in a manic episode or with psychotic features influences anxiety disorder comorbidity.

Recurrent unipolar mania: A comparative, cross-sectional study

INTRODUCTION

A significant number of patients experience recurrent episodes of mania without depressive episodes. Evidence from the available literature suggests that these patients differ from typical "bipolar" or "manic-depressive" patients, but results have been inconsistent. The current study aims to add to this literature by comparing the demographic, clinical and risk factor profiles of patients with recurrent mania with and without depression.

METHODS

66 patients with a diagnosis of bipolar I disorder were divided into "unipolar mania" (recurrent mania alone, MA) and "bipolar" (both mania and depression, MD) sub-groups. Comorbid diagnoses were assessed using the Mini International Neuropsychiatric Interview (MINI), and genetic and environmental risk factors were explored using the Diagnostic Interview for Genetic Studies (DIGS), Childhood Trauma Questionnaire (CTQ), and an additional questionnaire designed for the purpose of the study. Differences between the MA and MD groups in terms of demographic variables, clinical profile, comorbidities and antecedent risk factors were explored.

RESULTS

Patients with both mania and depression had higher frequencies of lifetime suicide attempts, antidepressant treatment, and catatonic symptoms. There was some evidence of an association between overcrowding in childhood and the presence of depressive episodes. No other differences in demographic, clinical or risk factor variables could be found between the two groups.

DISCUSSION

Our results are consistent with the view that unipolar mania is not a distinctive disorder, or even a distinctive subtype of bipolar disorder. However, this conclusion is provisional as it is based only on clinical and demographic data.

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.

Epidemiology and course of unipolar mania: results from the national epidemiologic survey on alcohol and related conditions (NESARC)

BACKGROUND

Unipolar mania (UM), in which only manic episodes occur during the course of illness, may be an important clinical manifestation of bipolar disorder that is under-recognized and understudied. The aim of this study is, for the first time, to examine the prevalence of UM and its clinical characteristics in the community.

METHODS

Among a total of 1,411 subjects with bipolar I disorder, we evaluated the prevalence of UM using three different criteria proposed in previous studies. We compared the clinical characteristics of subjects with UM to those with a more classic bipolar presentation with mania and lifetime major depressive episode (MDE). We additionally explored the proportion of subjects with UM who later experience at least one MDE during a 3-year follow-up period and determined risk factors for converting from UM to classic bipolar disorder.

RESULTS

The prevalence rate of UM among those with bipolar disorder ranged from 5.0 to 7.2% depending on the criteria. UM was more common in male and nonwhite subjects. About half of individuals with UM experienced subthreshold depression. Individuals with UM had lower rates of comorbid anxiety disorders or attention deficit hyperactivity disorder (ADHD). During the follow-up, about 18% of subjects with UM experienced MDEs. Male, nonwhite, comorbid generalized anxiety disorder and ADHD predicted an increased transition from UM to classic bipolar disorder. Subthreshold depression was not associated with the risk of the transition.

CONCLUSIONS

UM is an infrequent but clinically distinct subtype of bipolar I disorder. Further research delineating the characteristics of UM is warranted.

Unipolar mania: recent updates and review of the literature

Introduction. Unipolar mania (UM) has received less than the expected attention, when compared to its contemporary mood disorders, unipolar depression (UD) and bipolar disorder (BD). Method. The literature search included PUBMED and PSYCINFO databases. Cross-searches of key references were made to identify other articles of importance. Results. There seems to be a bipolar subgroup with a stable, unipolar recurrent manic course. Although UM does not have significant differences from bipolar mania in terms of sociodemographic variables, there are certain significant differences in clinical features. UM is reported to have more grandiosity, psychotic symptoms, and premorbid hyperthymic temperament, but less rapid cycling, suicidality, seasonality, and comorbid anxiety disorders. It seems to have a better course of illness with better social and professional adjustment. However, its response to lithium prophylaxis is found to be poor as compared to classical BD and valproate could be a better choice in this case. Conclusion. The available literature suggests that UM has certain differences from classical BD. The evidence, however, is insufficient to categorize it as separate diagnostic entity. However, considering UM as a course specifier of BD would be a reasonable step.

Unipolar mania: a distinct entity?

BACKGROUND

Whether or not unipolar mania is a separate nosological entity remains a subject of dispute. This review discusses that question in light of recent data.

METHODS

Unipolar mania studies in the PUBMED database and relevant publications and cross-references were searched.

RESULTS

There seems to be a bipolar subgroup with a stable, unipolar recurrent manic course, and that 15-20% of bipolar patients may be unipolar manic. Unipolar mania may be more common in females. It seems to have a slightly earlier age of illness onset, more grandiosity, psychotic symptoms, hyperthymic temperament, but less rapid-cycling, suicidality and comorbid anxiety disorders. It seems to have a better course of illness with better social and professional adjustment. However, its response to lithium prophylaxis seems to be worse, although its response to valproate is the same when compared to that of classical bipolar.

LIMITATIONS

The few studies on the subject are mainly retrospective, and the primary methodological criticism is the uncertainty of the diagnostic criteria for unipolar mania.

CONCLUSIONS

The results indicate that unipolar mania displays some different clinical characteristics from those of classical bipolar disorder. However, whether or not it is a separate nosological entity has not been determined due to the insufficiency of relevant data. Further studies with standardized diagnostic criteria are needed. Considering unipolar mania as a course specifier of bipolar disorder could be an important step in this respect.