Comparative familial aggregation of bipolar disorder in patients with bipolar I and bipolar II disorders

OBJECTIVE

We sought to quantify the prevalence and differential prevalence of a bipolar disorder among family members of patients with a bipolar I or II disorder.

METHODS

The sample comprised 1165 bipolar and 1041 unipolar patients, with the former then sub-typed as having either a bipolar I or II condition. Family history data was obtained via an online self-report tool.

RESULTS

Prevalence of a family member having a bipolar disorder (of either sub-type) was distinctive (36.8%). Patients with a bipolar I disorder reported a slightly higher family history (41.2%) compared to patients with a bipolar II disorder (36.3%), and with both significantly higher than the rate of bipolar disorder in family members of unipolar depressed patients (18.5%).

CONCLUSIONS

Findings support the view that bipolar disorder is heritable. The comparable rates in the two bipolar sub-types support the positioning of bipolar II disorder as a valid condition with strong genetic underpinnings.

The prevalence and outcomes of exposure to potentially traumatic stressful life events compared across patients with bipolar disorder and unipolar depression

This study examined the profile of stressful life experiences in patients with unipolar depression (UP) compared to bipolar disorder (BP), including their subsequent psychological impact and affirmation of post-traumatic stress symptoms. We studied 747 tertiary patients diagnosed with either a UP (n = 413) or BP condition (n = 334) according to a structured research interview and psychiatrist assessment. An online assessment collected additional study variables. Results showed that despite being younger in age, the BP group were more likely to have experienced 8 of the stressful life events, including childhood and adulthood abuse. However, both groups judged the consequential 'impact' of those events similarly. The BP group was significantly more likely than the UP group (45% vs. 36%) to affirm exposure to an extremely stressful event across their lifetime, resulting in 26.3% of the BP and 14.5% of the UP group affirming DSM-IV criteria for lifetime PTSD. The onset of DSM-IV-defined post-traumatic symptoms tended to occur in adulthood for both groups, with trauma often following the onset of the mood disorder. Thus, BP patients displayed greater vulnerability toward traumatic experiences and anxiety disorders, but reported a similar psychological impact in response to each stressor, compared with the UP group.

Targeting and transforming major depression

OBJECTIVE

To detail limitations to the construct of 'major depression', argue for repositioning it as a proxy for 'clinical depression' and then operationalize it and its principal constituent depressive subtypes, while preserving the DSM criteria-based format.

METHOD

We summarize limitations to major depression being viewed as a diagnostic entity. Data from 391 clinically depressed patients were analysed to identify high-prevalence non-specific depressive symptoms to define 'clinical depression' as well as the features showing specificity to a melancholic depressive subtype.

RESULTS

We identified a set of high-prevalence and generalized symptoms for defining clinical depression and with many being current criteria for major depression. We also developed a refined set of melancholic features and with their underlying distributions generating two classes that correlated strongly with clinical diagnoses of a melancholic or non-melancholic depression, thus validating its capacity to so differentiate. We append criteria sets for diagnosing clinical depression and its principal diagnostic subtypes (psychotic, melancholic and non-melancholic).

CONCLUSION

This heuristic study reframes and modifies major depression's criteria set to define a domain of clinical depression with additional criteria and then allowing the delineation of three diagnostic subtypes. If this paradigm shift is accepted and further refined, greater precision in diagnosis, treatment and research would be anticipated.

Are the bipolar disorders best modelled categorically or dimensionally?

OBJECTIVE

Considerable debate exists as to whether the bipolar disorders are best classified according to a categorical or dimensional model. This study explored whether there is evidence for a single or multiple subpopulations and the degree to which differing diagnostic criteria correspond to bipolar subpopulations.

METHOD

A mixture analysis was performed on 1081 clinically diagnosed (and a reduced sample of 497 DSM-IV diagnosed) bipolar I and II disorder patients, using scores on hypomanic severity (as measured by the Mood Swings Questionnaire). Mixture analyses were conducted using two differing diagnostic criteria and two DSM markers to ascertain the most differentiating and their associated clinical features.

RESULTS

The two subpopulation solution was most supported although the entropy statistic indicated limited separation and there was no distinctive point of rarity. Quantification by the odds ratio statistic indicated that the clinical diagnosis (respecting DSM-IV criteria, but ignoring 'high' duration) was somewhat superior to DSM-IV diagnosis in allocating patients to the putative mixture analysis groups. The most differentiating correlate was the presence or absence of psychotic features.

CONCLUSION

Findings favour the categorical distinction of bipolar I and II disorders and argue for the centrality of the presence or absence of psychotic features to subgroup differentiation.

Determinants of Treatment-Resistant Depression: The Salience of Benzodiazepines

Treatment-resistant depression (TRD) lacks consensus regarding its definition, despite being common in clinical practice. This study was designed to identify factors contributing to TRD in patients diagnosed with a major depressive disorder. Patients were grouped into "low," "medium," and "high" treatment-resistant (TR) groups based on the number of medications that had been prescribed for their depression. We identified a number of factors linked to TRD. The high TR group was generally older, had a longer depressive episode duration, a higher number of comorbid medical and anxiety disorders, a lower education, and were less likely to be in full-time employment. They also reported less trait irritability and were more likely to view medication as being a contributor to their current depression. Some differences between non-melancholic and melancholic subsets were evident and point to the benefits in research on TRD analyzing the two diagnostic groups separately. The most striking finding was benzodiazepine use, which was significantly more common in the high TR group and within both the melancholic and non-melancholic subsets. Some potential explanations for this finding are offered.

Anxious, irritable and hostile depression re-appraised

BACKGROUND

While classification of the depression disorders currently favors a dimensional model, this study considered the empirical support for a spectrum model linking personality with phenotypic depressive features, specifically examining patients with 'irritable', 'hostile' and 'anxious' depression.

METHODS

Pearson correlations were performed for Temperament and Personality (T&P) scales and state depressive patterns (irritable, hostile and anxious) for patients clinically diagnosed with unipolar melancholic and non-melancholic depressive conditions.

RESULTS

Irritable depression was most strongly associated with T&P irritability and anxious depression with T&P anxious-worrying - although these associations lacked specificity and were also correlated with other T&P scales. Hostile depression was most strongly correlated with T&P irritability suggesting that hostile and irritable depression are synonymous patterns. There were no clear indications for more distinct associations for the non-melancholic, compared to the melancholic, subset.

LIMITATIONS

Study findings are limited in that measures of state depressive patterns were relatively minimalistic and assignment to melancholic and non-melancholic conditions was measured by clinician judgment and may be subjective in nature.

CONCLUSIONS

Findings offer little support in the positioning of anxious and irritable/hostile depression as meaningfully differing patterns, nor for the spectrum model being more specific to the non-melancholic depressive conditions. There would appear to be little utility in preserving these depressive patterns as diagnostic constructs.

Clinical characteristics and temperament influences on 'happy' euphoric and 'snappy' irritable bipolar hypo/manic mood states

BACKGROUND

While mood elevation and euphoria are the most commonly described phenotypic descriptors of hypo/mania, irritability and anger may dominate. This study was designed to pursue possible determinants of such differing states.

METHODS

Patients with bipolar I or II disorder were assigned to an 'irritable/snappy' or 'euphoric/happy' sub-set on the basis of their dominant hypo/manic symptoms. Group differences were examined across clinical, personality, lifestyle and illness impact measures.

RESULTS

The two sub-sets did not differ on age of depression onset, family history of mood disorders, or depression severity and impairment. The snappy sub-set reported higher levels of irritability in depressed phases and were more likely to have a comorbid anxiety disorder. Their hypo/manic episodes were shorter and they were more likely to be hospitalized at such times. On a temperament measure they scored as more irritable and self-focussed and as less cooperative and effective - indicative of higher levels of disordered personality functioning.

LIMITATIONS

Some comparison analyses were undertaken on a reduced sample size, giving rise to power issues. Our bipolar I and II diagnoses deviated to some extent from DSM-5 criteria in not imposing duration criteria for hypo/manic episodes.

CONCLUSIONS

Findings support a spectrum model for the bipolar disorders linking temperament to bipolar symptomatic state and which may have treatment implications.

An evaluation of the DSM-5 rules defining mania and hypomania with identical symptom criteria

BACKGROUND

DSM-IV and DSM-5 provide identical symptom criteria and cut-off scores in defining mania and hypomania, a model seemingly counter-intuitive for classificatory differentiation. We designed a study to examine the impact of such DSM criteria and propose alternative models.

METHODS

Prevalence and severity of hypo/manic symptoms as measured by the Mood Swings Questionnaire (MSQ) were compared in age and gender-matched bipolar I and II patients. Use of the MSQ allowed both DSM and additional items to be evaluated in terms of their capacity to differentiate the two bipolar conditions.

RESULTS

In comparison to bipolar II participants, the bipolar I participants reported higher prevalence scores on six MSQ symptoms, severity scores on twelve MSQ symptoms and total MSQ scores. While bipolar I and II participants reported similar prevalence rates of DSM-5 symptoms, bipolar I participants returned higher prevalence rates on five (non-DSM) MSQ items.

LIMITATIONS

Bipolar sub-type was not formally assessed by a structured diagnostic interview. The degree to which assigned MSQ items corresponded with DSM items might not necessarily have high equivalence. The study would have been enriched by evaluating a number of other symptom constructs.

CONCLUSIONS

Findings suggest several optional approaches to differentiating mania and hypomania. The model we favor is one with a core set of features integral to mania and hypomania that is complemented by certain differentiating features. Psychotic features and over-valued ideas might provide the domain for such differentiation.

The duration of undiagnosed bipolar disorder: effect on outcomes and treatment response

INTRODUCTION

There are commonly long delays between the onset of bipolar disorder (BP), seeking of treatment and acquiring a bipolar disorder diagnosis. Whether a longer duration of undiagnosed bipolar disorder (DUBP) leads to an inferior treatment response is unclear in the literature.

METHOD

We conducted two studies with independent samples of BP patients who had received a first-time diagnosis of BP - first investigating whether DUBP was related to clinical and social outcomes at the time of assessment (n=173) and, second, whether response to mood stabiliser medication was affected by DUBP when assessed three months following assessment and intervention (n=64).

RESULTS

Participants׳ mean DUBP was 18-20 years (from the onset of mood episodes). After controlling for age, a longer DUBP was associated with employment difficulties, whereas a shorter DUBP was associated with a history of engaging in self-harm behaviours, as well as a reduced likelihood of experiencing social costs as consequence of the mood disorder. The majority of study variables were statistically unrelated to DUBP. In a multivariate analysis, age was the only predictor variable to make a significant contribution to the DUBP (33%). Across the 3-month intervention period, participants improved significantly on all but one outcome measure. The participants׳ likelihood to improve, become worse or experience minimal/no change over the study period was not significantly related to the DUBP.

LIMITATIONS

Self-reporting poses a risk to measurement precision. Being a naturalistic observation, no specific dose of medication was prescribed. The small sample of BP I patients provided insufficient statistical power to undertake meaningful separate analyses of the BP I and BP II participants.

CONCLUSION

Early detection and intervention remains important for helping to reduce morbidity and risks associated with untreated BP. However, the variation in DUBP was mostly a function of age and did not substantially affect clinical status at assessment, or lead to an inferior response to mood stabilising medication.

Screening for bipolar disorder: does gender distort scores and case-finding estimates?

BACKGROUND

Gender differences in rates of bipolar disorder have been described, with most studies reporting males as over-represented in those diagnosed with a bipolar I disorder and females over-represented in those diagnosed with a bipolar II disorder. This could reflect true differences in prevalence or measurement error emerging from screening or case-finding measures. We examine the possible contribution of the latter by examining one screening measure-the Mood Swings Questionnaire (MSQ).

METHODS

We analyse MSQ data from a large sample of age- and gender-matched bipolar I and bipolar II patients (and their composite group). Gender differences were examined in terms of prevalence and severity of MSQ symptoms, MSQ sub-scales scores and total MSQ scores, employing univariate and differential item functioning (DIF) analyses.

RESULTS

Both male and female bipolar I patients reported higher total MSQ and higher mysticism MSQ sub-scale scores than their male and female bipolar II counterparts. There were no gender differences when bipolar I, bipolar II and composite bipolar groups were separately examined on both total and sub-scale MSQ scores, suggesting that gender does not impact on MSQ scoring. When item analyses of bipolar I and II groups were undertaken separately, a number of differences emerged, but as few were consistent across bipolar sub-types such differences could reflect chance and failure to control for multiple comparisons. The over-representation of some items in females and some in males may have contributed to the comparable total and sub-scale scores.

LIMITATIONS

Large sample size and only one measure (i.e. MSQ) examined.

CONCLUSION

As total and sub-scale MSQ scores were uninfluenced by gender we can conclude that this screening test is not confounded by gender and, if representative of other such screening measures, would indicate that any differential prevalence of the bipolar disorders identified in community studies possibly reflects gender differences in their occurrence rather than artefactual consequences of screening measures having a gender bias.

The Mood Assessment Program is now on the Australian map

OBJECTIVE

To report on the wide uptake and utility of the freely available Mood Assessment Program (MAP) since its introduction as a tool to assist diagnosis and management of mood disorders.

METHOD

By mid-2012, some 16,000 patients had completed the MAP. We analyse data derived from such a sample.

RESULTS

The majority of patients utilizing this service were referred by general practitioners, psychologists and psychiatrists from within New South Wales (NSW). The great majority across age bands found the MAP easy to complete and judged that it covers issues relating to their mood disorder very well or completely.

CONCLUSION

The MAP is available for use Australia-wide with ready referral access for patients of mental health practitioners in general practice, psychiatry, psychology and social work. The online availability of the service makes it ideal for use in areas where access to health services is limited.

Bipolar depression: prototypically melancholic in its clinical features

BACKGROUND

Numerous studies have considered whether bipolar depression is phenomenologically similar or different to unipolar depression. While there have been some relatively consistent individual features identified, no clear clinical phenotype has been defined for bipolar depression.

METHODS

A self-report and clinician-rated measure of the Sydney Melancholia Prototype Index ('SMPI') was used to assess prototypic features of melancholic and non-melancholic depression in a sample of 901 patients clinically diagnosed with bipolar disorder or unipolar depression. The majority also completed a self-report (SDS) severity of depression measure, and provided current and historical data on depression, anxiety, global functioning and stressor severity.

RESULTS

Comparative analyses favoured the SMPI-CR above the SMPI-SR measure in terms of discriminatory strengths. The previously determined SMPI-CR difference score cut-off of 4 or more for differentiating melancholic from non-melancholic depression was replicated in this larger sample. SMPI item and prototypic pattern analyses indicated that bipolar depression corresponded closely to unipolar melancholic depression in terms of clinical pattern features but not in regard to a number of socio-demographic, illness course and correlate variables. 'Atypical features' were common across bipolar and unipolar disorders, but somewhat more prevalent in bipolar disorder.

LIMITATIONS

There was no distinction made for the bipolar group between subtypes I and II, with the study simply comparing bipolar with unipolar disorders. The apparent superiority of the clinician-rated in comparison to the SMPI-SR measure may reflect a clinician judgement bias.

CONCLUSIONS

The SMPI-CR measure indicated that bipolar depression corresponds closely to melancholic depression in terms of its clinical phenotype.

Discriminating melancholic and non-melancholic depression by prototypic clinical features

BACKGROUND

Melancholia is positioned as either a more severe expression of clinical depression or as a separate entity. Support for the latter view emerges from differential causal factors and treatment responsiveness but has not been convincingly demonstrated in terms of differential clinical features. We pursue its prototypic clinical pattern to determine if this advances its delineation.

METHODS

We developed a 24-item measure (now termed the Sydney Melancholia Prototype Index or SMPI) comprising 12 melancholic and 12 non-melancholic prototypic features (both symptoms and illness correlates). In this evaluative study, 278 patients referred for tertiary level assessment at a specialized mood disorders clinic completed the self-report SMPI as well as a depression severity measure and a comprehensive assessment schedule before clinical interview, while assessing clinicians completed a clinician version of the SMPI items following their interview. The independent variable (diagnostic gold standard) was the clinician's judgment of a melancholic versus non-melancholic depressive episode. Discriminative performance was evaluated by Receiver Operating Characteristics (ROC) analysis of four strategies for operationalising the SMPI self-report and SMPI clinician measures, and with the former strategies compared to ROC analysis of the depression severity measure. The external validity of the optimally discriminating scores on each measure was tested against a range of clinical variables.

RESULT

Comparison of the two self-report measures established that the SMPI provided greater discrimination than the depression severity measure, while comparison of the self-report and clinician-rated SMPI measures established the latter as more discriminating of clinically diagnosed melancholic or non-melancholic depression. ROC analyses favoured self-report SMPI distinction of melancholic from non-melancholic depression being most optimally calculated by a 'difference' score of at least four or more melancholic than non-melancholic items being affirmed (sensitivity of 0.69, specificity of 0.77). For the clinician-rated SMPI measure, ROC analyses confirmed the same optimal difference score of four or more as highly discriminating of melancholic and non-melancholic depression (sensitivity of 0.84, specificity of 0.92). As the difference score had positive predictive values of 0.90 and 0.70 (for the respective clinician-rated and self-report SMPI forms) and respective negative predictive values of 0.88 and 0.70, we conclude that the clinician-rated version had superior discrimination than the self-report version. External validating data quantified the self-rated and clinician-rated Index-assigned non-melancholic patients having a higher prevalence of anxiety disorders, a higher number of current and lifetime stressors, as well as elevated scores on several personality styles that are viewed as predisposing to and shaping such non-melancholic disorders.

LIMITATIONS

Assigned melancholic and non-melancholic diagnoses were determined by clinician judgement, risking a circularity bias across diagnostic assignment and clinical weighting of melancholic and non-melancholic features. The robustness of the Index requires testing in primary and secondary levels of care settings.

CONCLUSIONS

The clinician-rated SMPI differentiated melancholic and non-melancholic depressed subjects at a higher level of confidence than the self-report SMPI, and with a highly acceptable level of discrimination. The measure is recommended for further testing of its intrinsic and applied properties.

The categorisation of dysthymic disorder: can its constituents be meaningfully apportioned?

BACKGROUND

Since its introduction in DSM-III, the validity of dysthymia has been debated. Our objective is to further examine the concept of dysthymia in an outpatient sample, and explore whether its constituents can be meaningfully apportioned.

METHODS

318 patients attending the Black Dog Institute Depression Clinic were assessed by the Mini-International Neuropsychiatric Interview, and completed several self-report measures, in addition to a clinical assessment by an Institute psychiatrist. The characteristics of patients with major depressive disorder (MDD), dysthymic disorder and double depression were examined. Latent Class Analysis (LCA) and Latent Profile Analysis (LPA) were then conducted with the aim of detecting distinct classes based on depressive symptomatology and personality domains, respectively. Finally, clinicians' formulations of the study patients were examined.

RESULTS

Depression groups mainly differed on parameters of severity. Although LCA and LPA analyses indicated the presence of distinct classes, these only moderately correlated with the MINI-diagnosed groups. Finally, there was evidence for considerable heterogeneity within clinicians' formulations of dysthymia.

LIMITATIONS

Inadequate sample numbers for various measures limited the power of the LPA and our sample was weighted to patients with a more severe depressive condition which may affect the detection of a distinct 'dysthymic' personality profile.

CONCLUSIONS

Despite employing a variety of techniques, we were unable to obtain a clear homogeneous picture of dysthymia. Rather, there was evidence for a distinct heterogeneity in clinician-derived diagnoses. These findings allude to the questionable discriminant validity of dysthymia and may encourage future research and discussion on this important topic.

Temperament and personality in bipolar II disorder

BACKGROUND

There is limited research examining temperament and personality in bipolar II disorder. We sought to determine any over-represented temperament and personality features in bipolar II disorder compared to other affective groups.

METHOD

Scores on a self-report measure of temperament and personality were examined in a sample of 443 participants diagnosed with unipolar, bipolar I and bipolar II disorder.

RESULTS

After controlling for age, gender, age of depression onset and current depression severity, those with bipolar II disorder were characterized by higher irritability, anxious worrying, self-criticism and interpersonal sensitivity scores, and with lower social avoidance scores compared to unipolar participants. No differences were found between bipolar sub-types on any temperament and personality sub-scales. Limitations included the lack of a control group, a relatively small sample of bipolar I participants, and with the cross-sectional design disallowing conclusions regarding premorbid personality traits as opposed to illness 'scarring' effects.

CONCLUSIONS

Further research should seek to clarify whether certain temperament and personality styles are over-represented in bipolar II disorder. Any over-represented characteristics may assist with diagnostic differentiation from phenomenologically similar conditions and lead to more appropriate clinical management.

Examining the utility of the Black Dog Institute's online Mood Assessment Program in clinical practice

OBJECTIVE

To examine qualitatively the usefulness of the Mood Assessment Program (MAP) 12 months after an online version for patients was made available for access by Australian health practitioners.

METHOD

The MAP requires all those completing it to provide their observations on its ease of completion. In mid-2011, we also initiated a satisfaction study among current MAP referrers, with responses received from professionals (psychologists, general practitioners, psychiatrists and social workers).

RESULTS

Feedback from nearly 10,000 patients indicated that the great majority judged the MAP as straightforward to complete. Only 9% of professionals surveyed offered judgments about the utility of the MAP and we capture their judgments.

CONCLUSION

Responses supported the acceptability of the MAP by patients and its utility to clinicians in relation to diagnostic and formulation issues, as well as in advancing communication between practitioners and their patients. In addition, the MAP has been shown to improve efficiency and time management in assessing those with a mood disorder.