Factor structure of manic symptoms

Psychopathology of Mixed States

Mixed states are frequent clinical pictures in psychiatric practice but are not well described in nosologic systems. Debate exists as to defining mixed states. We review factor and cluster analytical studies and prominent clinical/conceptual models of mixed states. While mania involves standard manic symptoms and depression involves standard depressive symptoms, core additional features of the mixed state are, primarily, psychomotor activation and, secondarily, dysphoria. Those features are more pronounced in mixed mania than in mixed depression but are present in both.

The structure of mania: An overview of factorial analysis studies

Background.

Operational definitions of mania are based on expert consensus rather than empirical data. The aim of this study is to identify the key domains of mania, as well as the relevance of the different signs and symptoms of this clinical construct.

Methods.

A review of latent factor models studies in manic patients was performed. Before extraction, a harmonization of signs and symptoms of mania and depression was performed in order to reduce the variability between individual studies.

Results.

We identified 12 studies fulfilling the inclusion criteria and comprising 3039 subjects. Hyperactivity was the clinical item that most likely appeared in the first factor, usually covariating with other core features of mania, such as increased speech, thought disorder, and elevated mood. Depressive–anxious features and irritability–aggressive behavior constituted two other salient dimensions of mania. Altered sleep was frequently an isolated factor, while psychosis appeared related to grandiosity, lack of insight and poor judgment.

Conclusions.

Our results confirm the multidimensional nature of mania. Hyperactivity, increased speech, and thought disorder appear as core features of the clinical construct. The mood experience could be heterogeneous, depending on the co-occurrence of euphoric (elevated mood) and dysphoric (irritability and depressive mood) emotions of varying intensity. Results are also discussed regarding their relationship with other constitutive elements of bipolar disorder, such as mixed and depressive states.

Confirmatory test of two factors and four subtypes of bipolar disorder based on lifetime psychiatric co-morbidity

BACKGROUND

The first aim was to use confirmatory factor analysis (CFA) to test a hypothesis that two factors (internalizing and externalizing) account for lifetime co-morbid DSM-IV diagnoses among adults with bipolar I (BPI) disorder. The second aim was to use confirmatory latent class analysis (CLCA) to test the hypothesis that four clinical subtypes are detectible: pure BPI; BPI plus internalizing disorders only; BPI plus externalizing disorders only; and BPI plus internalizing and externalizing disorders.

METHOD

A cohort of 699 multiplex BPI families was studied, ascertained and assessed (1998-2003) by the National Institute of Mental Health Genetics Initiative Bipolar Consortium: 1156 with BPI disorder (504 adult probands; 594 first-degree relatives; and 58 more distant relatives) and 563 first-degree relatives without BPI. Best-estimate consensus DSM-IV diagnoses were based on structured interviews, family history and medical records. MPLUS software was used for CFA and CLCA.

RESULTS

The two-factor CFA model fit the data very well, and could not be improved by adding or removing paths. The four-class CLCA model fit better than exploratory LCA models or post-hoc-modified CLCA models. The two factors and four classes were associated with distinctive clinical course and severity variables, adjusted for proband gender. Co-morbidity, especially more than one internalizing and/or externalizing disorder, was associated with a more severe and complicated course of illness. The four classes demonstrated significant familial aggregation, adjusted for gender and age of relatives.

CONCLUSIONS

The BPI two-factor and four-cluster hypotheses demonstrated substantial confirmatory support. These models may be useful for subtyping BPI disorders, predicting course of illness and refining the phenotype in genetic studies.

The symptom structure of bipolar acute episodes: in search for the mixing link

OBJECTIVE

The nature of mixed mood episodes is still a matter of controversy amongst experts. Currently, the approach to this syndrome is mainly categorical and very restrictive. The factor-structure of bipolar mood episodes has not been studied yet. We performed a dimensional analysis of the structure of bipolar episodes aimed at identifying a factor deconstructing mixed episodes; furthermore, we analyzed correlations of factors emerging from the factorial analysis of the Brief Psychiatric Rating Scale (BPRS) with Temperament Evaluation of Memphis-Pisa-Paris-San Diego (TEMPS-A) and predominant polarity.

METHOD

187 consecutive bipolar I inpatients hospitalized for DSM-IV-TR acute mood episodes (depressive, manic or mixed) underwent a standardized assessment, including the 24-item Brief Psychiatric Rating Scale (BPRS 4.0), the 21-item Hamilton Depression Rating Scale (HDRS-21), the Young Mania Rating Scale (YMRS) and the TEMPS-A. Principal factor analysis was performed on BPRS-24 items.

RESULTS

This analysis revealed five factors corresponding to "psychosis", "euphoric mania", "mixity", "dysphoria" and "inhibited depression", capturing 71.89% of the rotated variance. The mixity factor was characterized by higher rates of suicidal ideation, more mixed episodes, higher frequencies of antidepressant (AD) use, depressive predominant polarity and anxious temperament.

DISCUSSION

The factor-structure of the BPRS in inpatients with bipolar I disorder with an acute episode of any type is pentafactorial; one factor identified is the mixity factor, which is independent from other factors and characterized by anxiety and motor hyperactivity and by the absence of motor retardation. Our results should prompt reconsideration of proposals for DSM-5 diagnostic criteria for the mixed features specifier. Limitations of the study include the relative small sample, the absence of drug-naïve patients and the use of rating scales no specific for mixed states.

Aggression and impulsivity as predictors of stress generation in bipolar spectrum disorders

BACKGROUND

Some evidence suggests that individuals with bipolar spectrum disorders (BSD) generate stressful life events, contributing to a more severe course of disorder. A recent update to the Behavioral Approach System (BAS) dysregulation theory of BSD highlights the need to investigate anger as approach motivation. Although research has shown that individuals with BSD generate stress, it is unclear whether personality traits characteristic of BSD, such as aggression and impulsivity, are related to this stress generation.

METHODS

The current longitudinal study employed multilevel modeling to examine stress generation in a sample of 104 individuals with BSD and 96 healthy controls. We examined rates of BAS-deactivating, BAS-activating, and Anger-evoking life events over a period of up to 4.5 years as a function of levels of aggression and impulsivity.

RESULTS

Individuals with BSD reported significantly higher numbers of dependent Anger-evoking events and BAS-deactivating events, but not dependent BAS-activating events, than controls. Trait levels of hostility and impulsivity predicted all types of events, although bipolar diagnosis remained a significant predictor of BAS-deactivating and Anger-evoking events.

LIMITATIONS

The life events measures were not designed to assess Anger-evoking events; further research should replicate these findings and develop more finely tuned assessments of stressful anger events. In addition, the sample was not a clinical sample.

CONCLUSIONS

This study adds to the literature on stress generation in BSD; trait level personality differences predict stress generation, beyond bipolar diagnosis. This also further establishes the importance of including anger-evoking events in the BAS model of BSDs and stress generation.

Psychometric evaluation of the DSM-IV criterion B mania symptoms in an Australian national sample

BACKGROUND

Although numerous studies have examined the latent structure of major depression, less attention has focused on mania. This paper presents the first investigation outside the USA to evaluate the psychometric properties of the DSM-IV criterion B mania symptoms using item response theory (IRT).

METHOD

Data were drawn from the Australian 2007 National Survey of Mental Health and Well-Being (NSMHWB, n = 8841). The psychometric performance of the mania symptoms was evaluated using a two-parameter logistic model. Because substance use disorders (SUDs) frequently co-occur with mania and can influence manic symptom expression, differential item functioning (DIF) between mania respondents with/without a SUD diagnosis was also assessed.

RESULTS

Factor analysis supported a unidimensional trait underlying mania. The grandiosity symptom displayed the highest discrimination whereas discrimination was lowest for decreased need for sleep. Relatively speaking, grandiosity tapped the severe end and increased goal-oriented activities tapped the mild end of the mania severity continuum. The symptoms generally performed equivalently between those with/without a SUD diagnosis, with one exception; the activities with painful consequences symptom was endorsed at lower levels of severity, and hence more frequently, by those with a SUD diagnosis versus those without a SUD diagnosis.

CONCLUSIONS

Accurate conceptualization of latent structure has crucial theoretical, statistical and clinical implications. The symptoms generally performed well in distinguishing between respondents with differing levels of liability, but others did not, suggesting modification is warranted to ensure optimal use in epidemiological samples. Given the dearth of psychometric evaluation studies of mania, further research replicating these results is necessary.

AKR1C4 gene variant associated with low euthymic serum progesterone and a history of mood irritability in males with bipolar disorder

BACKGROUND

Irritable mood during mood elevation is common in bipolar disorder. The progesterone metabolite allopregnanolone (ALLO) has been implicated in other disorders presenting with irritability. This study aimed to test whether a history of manic/hypomanic irritability is associated with low serum progesterone levels; and whether single nucleotide polymorphisms (SNPs) in gene coding for steroidogenetic enzymes (HSD3B2, SRD5A1 and AKR1C4 were coupled to previous manic irritability and/or with serum progesterone concentrations.

METHODS

Morning serum progesterone concentrations during euthymic phase of bipolar illness types 1 and 2 were assessed in 71 males and 107 females. Previous manic/hypomanic irritability was assessed using the Affective Disorders Evaluation. Selected SNPs were analyzed: i) aldoketoreductase-type-4 (AKR1C4 - rs17306779, rs3829125, rs10904440, rs12762017, and rs11253048), ii) 3-β-hydroxysteroid-dehydrogenase (HSD3B2 - rs4659174, rs2854964, and rs3765948), iii) steroid-5-α-reductase (SRD5A1 - rs8192139, rs181807, rs3822430, and rs3736316).

RESULTS

In males, progesterone concentrations were lower in those who had shown manic/hypomanic irritability compared with nonirritable (F=7.05, p=0.0099). SNPs rs17306779, rs3829125, and rs10904440 were associated with manic/hypomanic irritability. A cystine to serine change at position 145 in AKR1C4 (rs3829125) was associated with lower serum progesterone (F=6.34, p=0.014). There were no associations in females.

LIMITATIONS

Relatively small sample sizes.

CONCLUSION

Low progesterone levels and a cystine to serine change at position 145 in AKR1C4 gene are associated with manic/hypomanic irritability in males. Given that the enzyme AKR1C4 has both dehydrogenating and reductive activities in the steroidogenetic pathway, a missense variation in the gene may predispose to manic/hypomanic irritability by altering the relationship between progesterone and ALLO concentrations in the brain.

Signs and symptoms of acute mania: a factor analysis

BACKGROUND

The major diagnostic classifications consider mania as a uni-dimensional illness. Factor analytic studies of acute mania are fewer compared to schizophrenia and depression. Evidence from factor analysis suggests more categories or subtypes than what is included in the classification systems. Studies have found that these factors can predict differences in treatment response and prognosis.

METHODS

The sample included 131 patients consecutively admitted to an acute psychiatry unit over a period of one year. It included 76 (58%) males. The mean age was 44.05 years (SD = 15.6). Patients met International Classification of Diseases-10 (ICD-10) clinical diagnostic criteria for a manic episode. Patients with a diagnosis of mixed bipolar affective disorder were excluded. Participants were evaluated using the Young Mania Rating Scale (YMRS). Exploratory factor analysis (principal component analysis) was carried out and factors with an eigenvalue > 1 were retained. The significance level for interpretation of factor loadings was 0.40. The unrotated component matrix identified five factors. Oblique rotation was then carried out to identify three factors which were clinically meaningful.

RESULTS

Unrotated principal component analysis extracted five factors. These five factors explained 65.36% of the total variance. Oblique rotation extracted 3 factors. Factor 1 corresponding to 'irritable mania' had significant loadings of irritability, increased motor activity/energy and disruptive aggressive behaviour. Factor 2 corresponding to 'elated mania' had significant loadings of elevated mood, language abnormalities/thought disorder, increased sexual interest and poor insight. Factor 3 corresponding to 'psychotic mania' had significant loadings of abnormalities in thought content, appearance, poor sleep and speech abnormalities.

CONCLUSIONS

Our findings identified three clinically meaningful factors corresponding to 'elated mania', 'irritable mania' and 'psychotic mania'. These findings support the multidimensional nature of manic symptoms. Further evidence is needed to support the existence of corresponding clinical subtypes.

Cognitive manic symptoms associated with the P2RX7 gene in bipolar disorder

OBJECTIVE

  Several genetic loci have been suggested to be associated with bipolar disorder but results have been inconsistent. Studying associations between bipolar symptoms and candidate genes may better expose this relationship. Here we investigate the association between bipolar key symptoms and the P2RX7 gene.

METHODS

  Key symptoms of mania were rated in two sets of medicated bipolar disorder patients (n=171 and n=475) at two specialized outpatient clinics for affective disorders and three regular psychiatric outpatient units in Sweden. The relationships between all manic symptoms according to DSM-IV were entered in a principal component analysis. We used a case-case model to reduce the genetic heterogeneity and tested associations between four factors related to manic symptoms and their association to four single nucleotide polymorphisms in the P2RX7 gene.

RESULTS

  The combination of the cognitive symptoms, distractibility, talkativeness, and thought disorder was significantly associated with rs1718119 in the P2RX7 gene in Set 1 [odds ratio (OR) = 1.78; p=0.011]. The association was re-tested in the second set (OR = 1.42; p=0.009). In the total sample, the association was even stronger (OR = 1.49; p<0.001). None of the other factors was associated with the P2RX7 gene. Within the first factor, the distractibility symptom accounted for a significant portion of the association to rs1718119 (p=0.016).

CONCLUSION

  There is an association between specific symptoms of bipolar disorder and the P2RX7 gene. This finding may open up new approaches to elucidating the neurobiology behind bipolar symptoms.

Mood swing and mood stabilizer: how specific are these terms?

BACKGROUND

In the DSM-IIIR in 1987, the category title for depressive and bipolar disorders was changed from affective disorders to mood disorders. Within a short period of time thereafter, mood swing and mood stabilizer became very commonly used terms in psychiatry with bipolar implications.

METHODS

Terms and definitions in recent texts, articles, and dictionaries pertaining to mood fluctuations have been reviewed.

RESULTS

The term mood was seldom part of psychiatric terminology until the late 1970s. Mood swing and mood stabilizer as used in the psychiatric literature are primarily nonspecific and often misleading concepts--particularly as a basis for treatment decisions. Affective fluctuations and shifts to irritability and/or anger in persons with personality and depressive disorders are being viewed by many in the mental health field as cyclically biphasic--between depressed to elated--which is clearly at variance with research findings.

CONCLUSIONS

More data-based research on mood variations is needed to authoritatively remedy this situation.