A population-based analysis of distinguishers of bipolar disorder from major depressive disorder

Comparing Symptoms of Major Depression in Youth with Confirmed Versus Suspected Bipolar Disorder

Background: While numerous studies have compared symptoms of major depressive episodes (MDEs) associated with bipolar disorder (BD; i.e., bipolar depression) versus major depressive disorder (MDD; i.e., unipolar depression), little is known about this topic in youth. We compared MDE symptoms in youth with BD with youth with suspected BD who have similar clinical and familial characteristics aside from having BD. Methods: MDE symptoms based on Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children (K-SADS) Depression Rating Scale items for the most severe past episode were compared in youth, ages 13-21 years, with BD (n = 208) versus suspected BD (n = 165). Diagnoses were confirmed via semistructured interviews. Symptoms with between-group differences (p < 0.05) in univariate analyses were evaluated in a multivariate forward stepwise regression. All analyses controlled for age and sex. Results: Youth with BD had significantly higher (more severe) ratings on depressed mood (p = 0.001, η2 = 0.05), irritability (p = 0.037, η2 = 0.02), anhedonia (p = 0.004, η2 = 0.04), negative self-image (p < 0.001, η2 = 0.07), hopelessness (p = 0.04, η2 = 0.02), fatigue (p = 0.001, η2 = 0.05), hypersomnia (p = 0.001, η2 = 0.05), suicidal ideation (p = 0.04, η2 = 0.02), and recurrent thoughts of death (p < 0.001, η2 = 0.05). In regression analyses, the only symptom that remained significant in the BD group was depressed mood (p = 0.002). Conclusions: These findings demonstrate greater severity of depressive symptoms in youth with BD versus MDD across mood, and cognitive and neurovegetative symptom domains. These differences are especially noteworthy given that the MDD group was highly similar to the BD group, aside from BD diagnosis. Present findings emphasize the need for novel treatment approaches to bipolar depression in youth, and for studies examining potential mechanisms underlying the increased severity of bipolar depression.

Effect of high-definition transcranial direct current stimulation on improving depression and modulating functional activity in emotion-related cortical-subcortical regions in bipolar depression

Preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for bipolar depression, However, brain correlates of the depression alleviating are unclear. To determine the efficacy and safety of tDCS as an add-on treatment for patients with bipolar depression and further to identify the effect of tDCS on the resting-state brain activities, we recruited fifty patients with bipolar depression to complete the double-blind, sham-controlled and randomized clinical trial. Fourteen sessions of tDCS were performed once a day for 14 days. The anode was placed over F3 with return electrodes placed at FP1, FZ, C3 and F7. Regional homogeneity (ReHo) was examined on 50 patients with bipolar depression before and after 14-day active or sham tDCS. Patients in the active group showed significantly superior alleviating the depression symptoms compared with those receiving sham. The active group after 14-day active tDCS showed increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and decreased ReHo values in subcortical structures including hippocampus, parahippocampa gyrus, amygdala, putamen and lentiform nucleus. The reduction of depression severity showed positive correlation of increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and negative correlation of altered ReHo values in the putamen and lentiform. TDCS was an effective and safe add-on intervention for this small bipolar depression sample. The reduction of depression induced by tDCS is associated with a modulation of neural synchronization in the cortical and subcortical structures (ReHo values) within an emotion-related brain network.

Investigation of the impact of an ADCY2 polymorphism as a predictive biomarker in bipolar disorder, suicide tendency and response to lithium carbonate therapy: the first report from Iran

High rates of mortality due to both suicide and medical comorbidities in bipolar patients can be decreased through the administration of lithium, which affects the cerebral endothelium as well as neurons. To investigate the role of ADCY2 in risk of bipolar disorder, we genotyped the ADCY2 rs2290910 in bipolar patients and healthy controls using amplification refractory mutation system PCR. This polymorphism was associated with risk of bipolar disorder (odds ratio [OR]: 0.430; 95% CI: 0.296-0.624; p = 0.001). The C allele was more frequent in suicide ideation group compared other groups (OR: 2.7; 95% CI: 1.386-5.302; p = 0.004). The T allele was more frequent in suicide attempt group compared with suicide ideation group (OR: 0.238; 95% CI: 0.111-0.509; p = 0.001).

Assessing Relationships Among Impulsive Sensation Seeking, Reward Circuitry Activity, and Risk for Psychopathology: A Functional Magnetic Resonance Imaging Replication and Extension Study

BACKGROUND

High trait impulsive sensation seeking (ISS), the tendency to engage in behavior without forethought and to seek out new or extreme experiences, is a transdiagnostic risk factor for externalizing and mood disorders, particularly bipolar disorder. We published a positive association between trait ISS and reward expectancy-related activity in the left ventrolateral prefrontal cortex (L vlPFC) and the ventral striatum. We aimed to replicate this finding and extend it by testing for mediation effects of ISS on relationships between reward expectancy-related activity and measures denoting hypomania.

METHODS

A transdiagnostic sample of 127 adults, 18 to 25 years of age, completed a card-guessing functional magnetic resonance imaging task as well as measures of ISS (inattention, motor impulsivity, fun seeking, positive and negative urgency) and the Moods Spectrum as a measure of hypomania. An original sample of 98 was included for confirmatory and mediation analyses.

RESULTS

We replicated a positive relationship between reward expectancy-related L vlPFC activity and negative urgency, an ISS component (β = .28, t = 2.44, p = .0169). We combined these data with the original sample, confirming this finding (β = .27, t = 2.41, p = .0184). Negative urgency statistically mediated the relationship between reward expectancy-related L vlPFC activity and Moods Spectrum factors associated with hypomania. No other associations between ISS measures and reward expectancy-related activity were replicated.

CONCLUSIONS

We replicated findings showing that reward expectancy-related L vlPFC activity is a biomarker for negative urgency, the tendency to react with frustration during distressing conditions. Negative urgency also statistically mediated the relationship between L vlPFC activity and measures indicative of hypomanic symptoms.

Structural alterations associated with suicide attempts in major depressive disorder and bipolar disorder: A diffusion tensor imaging study

BACKGROUND

Major depressive disorder (MDD) and bipolar disorder (BD) are major affective disorders associated with high risk for suicide. Neural mechanisms underlying suicide attempts are poorly understood in MDD and BD but likely relate to the structural abnormalities in brain regions. In this study, we explored structural alterations in MDD and BD with prior suicide attempts (SA) using diffusion tensor imaging (DTI).

METHODS

Participants consisted of 27 MDD patients with prior SA (men: 9; age means±sd: 28.04 ± 11.06 years), 49 MDD patients without prior SA (men: 11; age means±sd: 30.03 ± 0.91 years), 25 BD patients with prior SA (men: 7, age means±sd: 27.08 ± 8.40 years), 49 BD patients without prior SA (men: 26, means±sd: 27.69 ± 9.97 years)，and 49 healthy controls (HC) (men: 18, means±sd: 31.12 ± 9.95 years). All participants underwent DTI to examine fractional anisotropy (FA) in brain regions.

RESULTS

FA in several major white matter (WM) bundles including bilateral inferior fronto-occipital fasciculus (IFOF), bilateral uncinate fasciculus (UF), and the corpus callosum (CC) was shown in MDD with prior SA, compared to MDD without prior SA and HC. Decreased FA was also found in bilateral IFOF, bilateral UF, and CC, as well as other WM bundles, in BD with prior SA, compared to BD without prior SA and HC. Significant diagnostic group by SA effects were shown in bilateral thalami with lowest mean FA values in MDD with prior SA.

CONCLUSIONS

Our findings support the involvement of structural alterations in suicide attempts in major affective disorders. Shared and distinct structural alterations were shown in MDD and BD with prior SA, suggesting common and differential neural pathways for suicide among major affective disorder.

Mania- and anxiety-like behavior and impaired maternal care in female diacylglycerol kinase eta and iota double knockout mice

Genome-wide association studies linked diacylglycerol kinase eta and iota to mood disorders, including bipolar disorder and schizophrenia, and both genes are expressed throughout the brain. Here, we generated and behaviorally characterized female mice lacking Dgkh alone, Dgki alone, and double Dgkh/Dgki-knockout (dKO) mice. We found that fewer than 30% of newborn pups raised by dKO females survived to weaning, while over 85% of pups survived to weaning when raised by wild-type (WT) females. Poor survival under the care of dKO mothers was unrelated to pup genotype. Moreover, pups from dKO dams survived when fostered by WT dams, suggesting the poor survival rate of dKO-raised litters was related to impaired maternal care by dKO dams. Nest building was similar between WT and dKO dams; however, some dKO females failed to retrieve any pups in a retrieval assay. Pups raised by dKO dams had smaller or absent milk spots and reduced weight, indicative of impaired nursing. Unlike WT females, postpartum dKO females showed erratic, panicked responses to cage disturbances. Virgin dKO females showed behavioral signs of anxiety and mania, which were not seen in mice lacking either Dgkh or Dgki alone. Our research indicates that combined deletion of Dgkh and Dgki impairs maternal behavior in the early postpartum period, and suggests female dKO mice model symptoms of mania and anxiety.

Relationships between recurrence and polarity in major depressive disorders: Pooled analysis of the BRIDGE and BRIDGE-II-MIX cohorts

BACKGROUND

current classifications of mood disorders focus on polarity rather than recurrence, separating bipolar disorder from major depressive disorder (MDD). The aim of the present study is to explore the possible relationships between number and frequency of depressive episodes and clinical variables associated to bipolarity, in a large sample of MDD patients.

METHODS

the clinical characteristics of 7055 patients with MDD were analyzed and compared according to the number and frequency of depressive episodes. Two stepwise backward logistic regression model were used to identify the predictive value of clinical features based on the presence of high number (≥3 episodes) and high frequency (≥3 episodes/year) of depressive episodes.

RESULTS

high-recurrence and high-frequency MDD patients showed greater family history for bipolar disorder, higher prevalence of psychotic features, more suicide attempts, higher rates of treatment resistance and mood switches with antidepressants (ADs) and higher rates of bipolarity diagnosis according to Angst criteria, compared to low-recurrence and low-frequency patients. Logistic regressions showed that a brief current depressive episode, a previous history of treatment resistance and AD-induced mood switches, a diagnosis of bipolarity and comorbid borderline personality disorder were the variables associated with both high-recurrence and high-frequency depression.

LIMITATIONS

the study participating centers were not randomly selected and several variables were retrospectively assessed.

CONCLUSIONS

even in the absence of hypomanic/manic episodes, high-recurrence and high-frequency MDD seem to be in continuity with the bipolar spectrum disorders in terms of clinical features and, perhaps, treatment response.

Comorbidity of bipolar and anxiety disorders: An overview of trends in research

Over the last three decades burgeoning research has shown that anxiety disorder comorbidity is not only highly prevalent in bipolar disorder (BD), but it also adversely impacts the course, outcome, and treatment of BD. The present review provides an overview of the current trends in research on comorbid anxiety and BDs based on prior reviews and meta-analyses (n = 103), epidemiological surveys, and large-scale clinical studies. The results reiterated the fact that at least half of those with BD are likely to develop an anxiety disorder in their lifetimes and a third of them will manifest an anxiety disorder at any point of time. All types of anxiety disorders were equally common in BD. However, there was a wide variation in rates across different sources, with most of this discrepancy being accounted for by methodological differences between reports. Comorbid anxiety disorders negatively impacted the presentation and course of BD. This unfavourable clinical profile led to poorer outcome and functioning and impeded treatment of BD. Despite the extensive body of research there was paucity of data on aetiology and treatment of anxiety disorder comorbidity in BD. Nevertheless, the substantial burden and unique characteristics of this comorbidity has important clinical and research implications.

Reducing relapse and suicide in bipolar disorder: practical clinical approaches to identifying risk, reducing harm and engaging service users in planning and delivery of care – the PARADES (Psychoeducation, Anxiety, Relapse, Advance Directive Evaluation and Suicidality) programme

Background

Bipolar disorder (BD) costs £5.2B annually, largely as a result of incomplete recovery after inadequate treatment.

Objectives

A programme of linked studies to reduce relapse and suicide in BD.

Design

There were five workstreams (WSs): a pragmatic randomised controlled trial (RCT) of group psychoeducation (PEd) versus group peer support (PS) in the maintenance of BD (WS1); development and feasibility RCTs of integrated psychological therapy for anxiety in bipolar disorder (AIBD) and integrated for problematic alcohol use in BD (WS2 and WS3); survey and qualitative investigations of suicide and self-harm in BD (WS4); and survey and qualitative investigation of service users’ (SUs) and psychiatrists’ experience of the Mental Capacity Act 2005 (MCA), with reference to advance planning (WS5).

Setting

Participants were from England; recruitment into RCTs was limited to certain sites [East Midlands and North West (WS1); North West (WS2 and WS3)].

Participants

Aged ≥ 18 years. In WS1–3, participants had their diagnosis of BD confirmed by the Structural Clinical Interview for theDiagnostic and Statistical Manual of Mental Disorders.

Interventions

In WS1, group PEd/PS; in WS3 and WS4, individual psychological therapy for comorbid anxiety and alcohol use, respectively.

Main outcome measures

In WS1, time to relapse of bipolar episode; in WS2 and WS3, feasibility and acceptability of interventions; in WS4, prevalence and determinants of suicide and self-harm; and in WS5, professional training and support of advance planning in MCA, and SU awareness and implementation.

Results

Group PEd and PS could be routinely delivered in the NHS. The estimated median time to first bipolar relapse was 67.1 [95% confidence interval (CI) 37.3 to 90.9] weeks in PEd, compared with 48.0 (95% CI 30.6 to 65.9) weeks in PS. The adjusted hazard ratio was 0.83 (95% CI 0.62 to 1.11; likelihood ratio testp = 0.217). The interaction between the number of previous bipolar episodes (1–7 and 8–19, relative to 20+) and treatment arm was significant (χ2 = 6.80, degrees of freedom = 2;p = 0.034): PEd with one to seven episodes showed the greatest delay in time to episode. A primary economic analysis indicates that PEd is not cost-effective compared with PS. A sensitivity analysis suggests potential cost-effectiveness if decision-makers accept a cost of £37,500 per quality-adjusted life-year. AIBD and motivational interviewing (MI) cognitive–behavioural therapy (CBT) trials were feasible and acceptable in achieving recruitment and retention targets (AIBD:n = 72, 72% retention to follow-up; MI-CBT:n = 44, 75% retention) and in-depth qualitative interviews. There were no significant differences in clinical outcomes for either trial overall. The factors associated with risk of suicide and self-harm (longer duration of illness, large number of periods of inpatient care, and problems establishing diagnosis) could inform improved clinical care and specific interventions. Qualitative interviews suggested that suicide risk had been underestimated, that care needs to be more collaborative and that people need fast access to good-quality care. Despite SUs supporting advance planning and psychiatrists being trained in MCA, the use of MCA planning provisions was low, with confusion over informal and legally binding plans.

Limitations

Inferences for routine clinical practice from WS1 were limited by the absence of a ‘treatment as usual’ group.

Conclusion

The programme has contributed significantly to understanding how to improve outcomes in BD. Group PEd is being implemented in the NHS influenced by SU support.

Future work

Future work is needed to evaluate optimal approaches to psychological treatment of comorbidity in BD. In addition, work in improved risk detection in relation to suicide and self-harm in clinical services and improved training in MCA are indicated.

Trial registration

Current Controlled Trials ISRCTN62761948, ISRCTN84288072 and ISRCTN14774583.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 6. See the NIHR Journals Library website for further project information.

Treatment of acute bipolar depression

Depression is the predominant pole of disability in bipolar disorder and compared with mania/hypomania, has less systematic research guiding the development of treatment especially in its acute phase (acute bipolar depression). The deficiency in the management of the acute bipolar depression largely reflects the natural divergence of opinion resulting from significant knowledge gaps. At present, there are only 3 approved drug treatments for acute bipolar depression: olanzapine/fluoxetine combination, quetiapine (immediate or extended release), and lurasidone (monotherapy or adjunctive to lithium or valproate). Nonapproved agents and nonpharmacologic treatment such as lamotrigine, antidepressants, modafinil, pramipexole, ketamine, and electroconvulsive therapy are often prescribed to treat acute bipolar depression. This article discusses the challenges of diagnosing bipolar depression, and reviews above treatment options for acute bipolar depression.

Is recurrence in major depressive disorder related to bipolarity and mixed features? Results from the BRIDGE-II-Mix study

BACKGROUND

Current classifications separate Bipolar (BD) from Major Depressive Disorder (MDD) based on polarity rather than recurrence. We aimed to determine bipolar/mixed feature frequency in a large MDD multinational sample with (High-Rec) and without (Low-Rec) >3 recurrences, comparing the two subsamples.

METHODS

We measured frequency of bipolarity/hypomanic features during current depressive episodes (MDEs) in 2347 MDD patients from the BRIDGE-II-mix database, comparing High-Rec with Low-Rec. We used Bonferroni-corrected Student's t-test for continuous, and chi-squared test, for categorical variables. Logistic regression estimated the size of the association between clinical characteristics and High-Rec MDD.

RESULTS

Compared to Low-Rec (n = 1084, 46.2%), High-Rec patients (n = 1263, 53.8%) were older, with earlier depressive onset, had more family history of BD, more atypical features, suicide attempts, hospitalisations, and treatment resistance and (hypo)manic switches when treated with antidepressants, higher comorbidity with borderline personality disorder, and more hypomanic symptoms during current MDE, resulting in higher rates of mixed depression according to both DSM-5 and research-based diagnostic (RBDC) criteria. Logistic regression showed age at first symptoms < 30 years, current MDE duration ≤ 1 month, hypomania/mania among first-degree relatives, past suicide attempts, treatment-resistance, antidepressant-induced swings, and atypical, mixed, or psychotic features during MDE to associate with High-Rec.

LIMITATIONS

Number of MDEs for defining recurrence was arbitrary; cross-sectionality did not allow assessment of conversion from MDD to BD.

CONCLUSIONS

High-Rec MDD differed from Low-Rec group for several clinical/epidemiological variables, including bipolar/mixed features. Bipolarity specifier and RBDC were more sensitive than DSM-5 criteria in detecting bipolar and mixed features in MDD.

Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder

The Canadian Network for Mood and Anxiety Treatments (CANMAT) previously published treatment guidelines for bipolar disorder in 2005, along with international commentaries and subsequent updates in 2007, 2009, and 2013. The last two updates were published in collaboration with the International Society for Bipolar Disorders (ISBD). These 2018 CANMAT and ISBD Bipolar Treatment Guidelines represent the significant advances in the field since the last full edition was published in 2005, including updates to diagnosis and management as well as new research into pharmacological and psychological treatments. These advances have been translated into clear and easy to use recommendations for first, second, and third- line treatments, with consideration given to levels of evidence for efficacy, clinical support based on experience, and consensus ratings of safety, tolerability, and treatment-emergent switch risk. New to these guidelines, hierarchical rankings were created for first and second- line treatments recommended for acute mania, acute depression, and maintenance treatment in bipolar I disorder. Created by considering the impact of each treatment across all phases of illness, this hierarchy will further assist clinicians in making evidence-based treatment decisions. Lithium, quetiapine, divalproex, asenapine, aripiprazole, paliperidone, risperidone, and cariprazine alone or in combination are recommended as first-line treatments for acute mania. First-line options for bipolar I depression include quetiapine, lurasidone plus lithium or divalproex, lithium, lamotrigine, lurasidone, or adjunctive lamotrigine. While medications that have been shown to be effective for the acute phase should generally be continued for the maintenance phase in bipolar I disorder, there are some exceptions (such as with antidepressants); and available data suggest that lithium, quetiapine, divalproex, lamotrigine, asenapine, and aripiprazole monotherapy or combination treatments should be considered first-line for those initiating or switching treatment during the maintenance phase. In addition to addressing issues in bipolar I disorder, these guidelines also provide an overview of, and recommendations for, clinical management of bipolar II disorder, as well as advice on specific populations, such as women at various stages of the reproductive cycle, children and adolescents, and older adults. There are also discussions on the impact of specific psychiatric and medical comorbidities such as substance use, anxiety, and metabolic disorders. Finally, an overview of issues related to safety and monitoring is provided. The CANMAT and ISBD groups hope that these guidelines become a valuable tool for practitioners across the globe.

Structural and metabolic differentiation between bipolar disorder with psychosis and substance-induced psychosis: An integrated MRI/PET study

BACKGROUND

Bipolar disorder (BD) may be characterized by the presence of psychotic symptoms and comorbid substance abuse. In this context, structural and metabolic dysfunctions have been reported in both BD with psychosis and addiction, separately. In this study, we aimed at identifying neural substrates differentiating psychotic BD, with or without substance abuse, versus substance-induced psychosis (SIP) by coupling, for the first time, magnetic resonance imaging (MRI) and positron emission tomography (PET).

METHODS

Twenty-seven BD type I psychotic patients with (n=10) or without (n=17) substance abuse, 16 SIP patients and 54 healthy controls were enrolled in this study. 3T MRI and 18-FDG-PET scanning were acquired.

RESULTS

Gray matter (GM) volume and cerebral metabolism reductions in temporal cortices were observed in all patients compared to healthy controls. Moreover, a distinct pattern of fronto-limbic alterations were found in patients with substance abuse. Specifically, BD patients with substance abuse showed volume reductions in ventrolateral prefrontal cortex, anterior cingulate, insula and thalamus, whereas SIP patients in dorsolateral prefrontal cortex and posterior cingulate. Common alterations in cerebellum, parahippocampus and posterior cingulate were found in both BD with substance abuse and SIP. Finally, a unique pattern of GM volumes reduction, with concomitant increased of striatal metabolism, were observed in SIP patients.

CONCLUSIONS

These findings contribute to shed light on the identification of common and distinct neural markers associated with bipolar psychosis and substance abuse. Future longitudinal studies should explore the effect of single substances of abuse in patients at the first-episode of BD and substance-induced psychosis.

Suicide attempts and clinical features of bipolar patients

OBJECTIVES

To identify clinical predictors of suicide attempts in patients with bipolar disorder.

METHODS

This study included bipolar patients who were treated in the Psychiatry Department, Haseki Training and Research Hospital, Istanbul, Turkey, between 2013 and 2014; an informed consent was obtained from the participants. Two  hundred and eighteen bipolar patients were assessed by using the structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) Axis-I (SCID-I) in order to detect all possible psychiatric comorbid diagnoses. Clinical predictors of suicide attempts were examined in attempters and non-attempters. The study design was retrospective.

RESULTS

The lifetime suicide attempt rate for the entire sample was 19.2%. Suicide attempters with bipolar disorder had more lifetime comorbidity of eating disorder. Female gender and family history of mood disorder were significant predictors for suicide attempts. There was no difference between groups in terms of bipolar disorder subtype, onset age of bipolar disorder, total number of episodes, first and predominant episode type, suicide history in first degree relatives, severity of episodes, and hospitalization and being psychotic.

CONCLUSION

Our study revealed that female gender, family history of mood disorder, and eating disorder are more frequent in bipolar patients with at least one suicide attempt.

Bipolar disorder

Bipolar disorder is a recurrent chronic disorder characterised by fluctuations in mood state and energy. It affects more than 1% of the world's population irrespective of nationality, ethnic origin, or socioeconomic status. Bipolar disorder is one of the main causes of disability among young people, leading to cognitive and functional impairment and raised mortality, particularly death by suicide. A high prevalence of psychiatric and medical comorbidities is typical in affected individuals. Accurate diagnosis of bipolar disorder is difficult in clinical practice because onset is most commonly a depressive episode and looks similar to unipolar depression. Moreover, there are currently no valid biomarkers for the disorder. Therefore, the role of clinical assessment remains key. Detection of hypomanic periods and longitudinal assessment are crucial to differentiate bipolar disorder from other conditions. Current knowledge of the evolving pharmacological and psychological strategies in bipolar disorder is of utmost importance.

Suicide Behaviors in Bipolar Disorder: A Review and Update for the Clinician

Suicide behaviors (ideation, attempts, and completions) are unfortunately common in patients with bipolar disorder. It is estimated that 25 to 50% attempt suicide at least once during their lifetime, and 6% to 19% complete suicide. Risk factors include a family history of suicide, previous suicide attempts, younger age of onset, comorbid psychiatric illnesses, and psychological constructs like hopelessness. Pharmacologic treatment may impact suicidal behaviors, either increasing vulnerability or resilience. Clinicians need to be particularly sensitive to their patient's thoughts and beliefs about death, particularly during stressful times of life or when in a depressive/mixed episode of bipolar disorder.

Diagnosis of bipolar disorder in primary and secondary care: what have we learned over a 10-year period?

BACKGROUND

Studies suggest that misdiagnosis of bipolar disorders (BD) is frequent in primary care. This study aimed to evaluate agreement between referral for BD by general practitioners (GP) and BD diagnosis by secondary care psychiatrists, and to evaluate the impact of age, gender, and BD type on agreement.

METHODS

The study was conducted at Hôpital du Sacré-Coeur de Montréal׳s "Module Evaluation/Liaison" (MEL), which establishes/clarifies psychiatric diagnoses requested mainly from GPs and directs patients to appropriate treatment and care. Socio-demographic variables, reason for referral, and psychiatric diagnosis were compiled for patients assessed from 1998 to 2010. GP-psychiatrist agreement was established for BD type, gender, and age group (18-25, 26-35, 36-45, >45) using Cohen׳s Kappa coefficient (Κ).

RESULTS

From 1998 to 2010, MEL psychiatrists received 18,111 requests and carried out 10,492 (58%) assessments. There were 583 referrals for BD suspicion, while 640 assessments (6.1%) received a BD diagnosis (40.3% type I, 40.5% type II). The overall K was 0.35 (95% CI [0.31, 0.38]), and was significantly higher for type I than type II (I=0.35, 95% CI [0.30, 0.39]; II=0.25, 95% CI [0.21, 0.30]), though age group and gender had no impact.

LIMITATIONS

Reasons for referral were converted into keywords and categories to facilitate agreement analyses. Only the main psychiatric diagnosis was available.

CONCLUSIONS

Our study suggests diagnosing BD remains strenuous, regardless of age and gender, though BD type I seems better understood by primary care GPs. The true measure of BD diagnosis remains a critical issue in clinical practice.

International Society for Bipolar Disorders Task Force on Suicide: meta-analyses and meta-regression of correlates of suicide attempts and suicide deaths in bipolar disorder

OBJECTIVES

Bipolar disorder is associated with a high risk of suicide attempts and suicide death. The main objective of the present study was to identify and quantify the demographic and clinical correlates of attempted and completed suicide in people with bipolar disorder.

METHODS

Within the framework of the International Society for Bipolar Disorders Task Force on Suicide, a systematic review of articles published since 1980, characterized by the key terms bipolar disorder and 'suicide attempts' or 'suicide', was conducted, and data extracted for analysis from all eligible articles. Demographic and clinical variables for which ≥ 3 studies with usable data were available were meta-analyzed using fixed or random-effects models for association with suicide attempts and suicide deaths. There was considerable heterogeneity in the methods employed by the included studies.

RESULTS

Variables significantly associated with suicide attempts were: female gender, younger age at illness onset, depressive polarity of first illness episode, depressive polarity of current or most recent episode, comorbid anxiety disorder, any comorbid substance use disorder, alcohol use disorder, any illicit substance use, comorbid cluster B/borderline personality disorder, and first-degree family history of suicide. Suicide deaths were significantly associated with male gender and first-degree family history of suicide.

CONCLUSIONS

This paper reports on the presence and magnitude of the correlates of suicide attempts and suicide deaths in bipolar disorder. These findings do not address causation, and the heterogeneity of data sources should limit the direct clinical ranking of correlates. Our results nonetheless support the notion of incorporating diagnosis-specific data in the development of models of understanding suicide in bipolar disorder.

Brain changes in early-onset bipolar and unipolar depressive disorders: a systematic review in children and adolescents

Pediatric bipolar disorder (BD) and unipolar disorder (UD) share common symptomatic and functional impairments. Various brain imaging techniques have been used to investigate the integrity of brain white matter (WM) and gray matter (GM) in these disorders. Despite promising preliminary findings, it is still unclear whether these alterations may be considered as common trait markers or may be used to distinguish BD from UD. A systematic literature search of studies between 1980 and September 2013 which reported WM/GM changes in pediatric and adolescent BD/UD, as detected by diffusion tensor imaging and voxel-based analysis was conducted. Of the 34 articles judged as eligible, 17 fulfilled our inclusion criteria and were finally retained in this review. More abnormalities have been documented in the brains of children and adolescents with BD than UD. Reductions in the volume of basal ganglia and the hippocampus appeared more specific for pediatric UD, whereas reduced corpus callosum volume and increased rates of deep WM hyperintensities were more specific for pediatric BD. Seminal papers failed to address the possibility that the differences between unipolar and bipolar samples might be related to illness severity, medication status, comorbidity or diagnosis. UD and BD present both shared and distinctive impairments in the WM and GM compartments. More WM abnormalities have been reported in children and adolescents with bipolar disease than in those with unipolar disease, maybe as a result of a low number of DTI studies in pediatric UD. Future longitudinal studies should investigate whether neurodevelopmental changes are diagnosis-specific.

A randomized, double-blind, placebo-controlled trial of pregnenolone for bipolar depression

Depression in bipolar disorder (BPD) is challenging to treat. Therefore, additional medication options are needed. In the current report, the effect of the neurosteroid pregnenolone on depressive symptoms in BPD was examined. Adults (n=80) with BPD, depressed mood state, were randomized to pregnenolone (titrated to 500 mg/day) or placebo, as add-on therapy, for 12 weeks. Outcome measures included the 17-item Hamilton Rating Scale for Depression (HRSD), Inventory of Depressive Symptomatology-Self-Report (IDS-SR), Hamilton Rating Scale for Anxiety (HRSA), and Young Mania Rating Scale (YMRS). Serum neurosteroid levels were assessed at baseline and week 12. Data were analyzed using a mixed model ANCOVA with a between factor of treatment assignment, a within factor (repeated) of visit, and the baseline value, as well as age and gender, as covariates. In participants with at least one postbaseline visit (n=73), a significant treatment by week interaction for the HRSD (F(5,288)=2.61, p=0.025), but not IDS-SR, was observed. Depression remission rates were greater in the pregnenolone group (61%) compared with the placebo group (37%), as assessed by the IDS-SR (χ(2)(1)=3.99, p=0.046), but not the HRSD. Large baseline-to-exit changes in neurosteroid levels were observed in the pregnenolone group but not in the placebo group. In the pregnenolone group, baseline-to-exit change in the HRSA correlated negatively with changes in allopregnanolone (r(22)=-0.43, p=0.036) and pregNANolone (r(22)=-0.48, p=0.019) levels. Pregnenolone was well tolerated. The results suggest that pregnenolone may improve depressive symptoms in patients with BPD and can be safely administered.

Clinical risk factors for bipolar disorders: a systematic review of prospective studies

BACKGROUND

Early phases and suspected precursor states of bipolar disorder are not well characterized. We evaluate the prevalence, duration, clinical features and predictive value of non-affective psychopathology as clinical risk factors for bipolar disorder in prospective studies.

METHODS

We screened PubMed, CINAHL, PsycINFO, Embase, SCOPUS, and ISI-Web of Science databases from inception up to January 31, 2014, following PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and searched: bipolar disorder AND [antecedent⁎ OR predict⁎ OR prodrom⁎ OR prospect⁎ OR risk⁎] AND [diagnosis OR development]. We included only English language reports on prospective, longitudinal studies with two structured clinical assessments (intake and follow-up); no DSM intake diagnosis of bipolar-I or -II; diagnostic outcome was bipolar-I or -II. Details of study design, risk factors, and predictive value were tabulated.

RESULTS

We found 16 published reports meeting selection criteria, with varying study design. Despite heterogeneity in methods, findings across studies were consistent. Clinical risk factors of bipolar disorder were early-onset panic attacks and disorder, separation anxiety and generalized anxiety disorders, conduct symptoms and disorder, ADHD, impulsivity and criminal behavior.

LIMITATIONS

Since risk factors identified in some prospective studies are predictive of other conditions besides bipolar disorder, these preliminary findings require replication, and their sensitivity, specificity and predictive value need to be assessed.

CONCLUSIONS

Clinical risk factors for bipolar disorder typically arise years prior to syndromal onset, include anxiety and behavioral disorders with unclear sensitivity and specificity. Prospectively identified clinical risk factors for bipolar disorder are consistent with retrospective and family-risk studies. Combining clinical risk factors with precursors and family-risk may improve early identification and timely and appropriate treatment of bipolar disorder.

Co-occurrence of anxiety and bipolar disorders: clinical and therapeutic overview

BACKGROUND

Anxiety commonly co-occurs with bipolar disorders (BDs), but the significance of such "co-morbidity" remains to be clarified and its optimal treatment adequately defined.

METHODS

We reviewed epidemiological, clinical, and treatment studies of the co-occurrence of BD and anxiety disorder through electronic searching of Pubmed/MEDLINE and EMBASE databases.

RESULTS

Nearly half of BD patients meet diagnostic criteria for an anxiety disorder at some time, and anxiety is associated with poor treatment responses, substance abuse, and disability. Reported rates of specific anxiety disorders with BD rank: panic ≥ phobias ≥ generalized anxiety ≥ posttraumatic stress ≥ obsessive-compulsive disorders. Their prevalence appears to be greater among women than men, but similar in types I and II BD. Anxiety may be more likely in depressive phases of BD, but relationships of anxiety phenomena to particular phases of BD, and their temporal distributions require clarification. Adequate treatment trials for anxiety syndromes in BD patients remain rare, and the impact on anxiety of treatments aimed at mood stabilization is not clear. Benzodiazepines are sometimes given empirically; antidepressants are employed cautiously to limit risks of mood switching and emotional destabilization; lamotrigine, valproate, and second-generation antipsychotics may be useful and relatively safe.

CONCLUSIONS

Anxiety symptoms and syndromes co-occur commonly in patients with BD, but "co-morbid" phenomena may be part of the BD phenotype rather than separate illnesses.

Comorbid anxiety disorders in Canadians with bipolar disorder: clinical characteristics and service use

OBJECTIVE

To examine the impact of anxiety disorders comorbid to bipolar disorder (BD) in a large, nationally representative sample, to describe the sociodemographic and clinical profiles of Canadians living with BD and with or without comorbid anxiety disorders, to identify the characteristics uniquely associated with comorbid anxiety, and to examine treatment patterns.

METHOD

We analyzed data from the Canadian Community Health Survey: Mental Health and Well-Being, conducted among 38 492 Canadians. People meeting the criteria for BD (n = 808) were compared based on the presence or absence of an assessed anxiety disorder (that is, social phobia, panic disorder, and agoraphobia).

RESULTS

People with BD and a comorbid anxiety disorder fare worse in terms of BD relapses, suicidality, and sleep disturbance, and are more likely to be taking psychiatric medication. They have more impairment in their work and social functioning and rate their health and life satisfaction lower. Despite the greater severity, they are not receiving additional psychological treatment, they feel they are not receiving the treatment they need, and they report more barriers to treatment.

CONCLUSIONS

This study confirms the critical impact of comorbid anxiety on the course of BD in a large, nationally representative sample and reveals that the psychological treatment needs of this population are not being met. Clinical and research implications are discussed.

Differential effects of depression and mania symptoms on social adjustment: prospective study in bipolar disorder

OBJECTIVES

Previous studies of social adjustment in bipolar disorder have been cross-sectional and small in sample size, have examined a limited number of roles, or were not controlled for baseline mood and other clinical, social, or treatment confounders. We aimed to prospectively explore the strength and stability of correlations between depression and mania-type symptoms and impairment in a broad range of social adjustment roles and domains.

METHODS

Multilevel modeling analysis of correlation coefficients between depression and mania-type symptoms with roles and domains of the modified social adjustment scale (overall, work, social/leisure, extended family, marital, parental social adjustment roles, performance, interpersonal behavior, friction, dependency, overactivity domains) was used. Interview assessments were made at eight-week intervals beginning at eight weeks and continuing through 72 weeks after baseline in 253 patients in a multicenter randomized controlled trial.

RESULTS

After controlling for baseline mood episodes, and other clinical, social, and treatment variables, depression symptoms showed strong and stable correlations over time with performance, overall social adjustment, and the work role; and a moderate but stable relationship with interpersonal behavior. The relationships of depression symptoms with the other roles were weak, non-significant, or not stable. For mania-type symptoms, only the correlation with interpersonal friction was moderately strong and reasonably stable over time. Mood episodes, substance use disorder, and borderline/antisocial personality disorder increased role impairment, while employment and marriage mildly decreased it.

CONCLUSIONS

Depression and mania-type symptoms have specific effects on social adjustment in bipolar I disorder. Depression symptoms are correlated strongly with performance and moderately with interpersonal behavior, while mania-type symptoms are correlated moderately with interpersonal friction.

Anxiety as a marker of severity in acute mania

OBJECTIVE

Anxiety has scarcely been studied in acute mania. The aim of this study was to assess anxiety symptoms during manic episodes and their impact on clinical outcomes.

METHOD

Observational, cross-sectional multicentre study. Anxiety was measured using the Hamilton Anxiety Rating Scale (HARS). Bivariate and multiple linear regression analyses were performed using the HARS score as the dependent variable.

RESULTS

Two hundred and forty-two patients admitted with a diagnosis of acute manic episode according to DSM-IV TR criteria and a Young Mania Rating Scale>20 were analysed. Mean age was 43 years (SD=11.9) and 57% were women. Forty-six per cent of patients (n=104) presented moderate to severe anxiety symptoms (HARS score>14). Anxiety was significantly associated with severity of manic symptoms (P<0.0001). Patients with anxiety had 20% longer hospitalizations (mean 21 days, CI95% 19.7-23.7).

CONCLUSION

An association of anxiety symptoms with greater severity in acute mania was demonstrated. The close relationship between anxiety and manic symptoms highlights the need for greater clinical attention to anxiety in this population. Further studies are necessary to determine whether effective treatment of anxiety symptoms could improve clinical and care outcomes.

Risks for the transition from major depressive disorder to bipolar disorder in the National Epidemiologic Survey on Alcohol and Related Conditions

OBJECTIVE

It is currently not possible to determine which individuals with unipolar depression are at highest risk for a manic episode. This study investigates clinical and psychosocial risk factors for mania among individuals with major depressive disorder (MDD), indicating diagnostic conversion from MDD to bipolar I disorder.

METHOD

We fitted logistic regression models to predict the first onset of a manic episode among 6,214 cases of lifetime MDD according to DSM-IV criteria in the National Epidemiologic Survey on Alcohol and Related Conditions. Participants in this survey were interviewed twice over a period of 3 years, in 2000-2001 and in 2004-2005, and survey data were gathered using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV.

RESULTS

Approximately 1 in 25 individuals with MDD transitioned to bipolar disorder during the study's 3-year follow-up period. Demographic risk factors for the transition from MDD to bipolar disorder included younger age, black race/ethnicity, and less than high school education. Clinical characteristics of depression (eg, age at first onset, presence of atypical features) were not associated with diagnostic conversion. However, prior psychopathology was associated with the transition to bipolar disorder: history of social phobia (odds ratio [OR] = 2.20; 95% confidence interval [CI], 1.47-3.30) and generalized anxiety disorder (OR = 1.58; 95% CI, 1.06-2.35). Lastly, we identified environmental stressors over the life course that predicted the transition to bipolar disorder: these include a history of child abuse (OR = 1.26; 95% CI, 1.12-1.42) and past-year problems with one's social support group (OR = 1.79; 95% CI, 1.19-2.68). The overall predictive power of these risk factors based on a receiver operating curve analysis is modest.

CONCLUSIONS

A wide range of demographic, clinical, and environmental risk factors were identified that indicate a heightened risk for the transition to bipolar disorder. Additional work is needed to further enhance the prediction of bipolar disorder among cases of MDD and to determine whether interventions targeting these factors could reduce the risk of bipolar disorder.

The importance of anxiety in both major depression and bipolar disorder

BACKGROUND

Generalized anxiety disorder (GAD) is frequently co-morbid with major depression (MDD), and this becomes more so when the duration requirement is relaxed. Both anxiety diagnoses and anxious symptoms are more common in both unipolar and bipolar depression. This paper explores the relationship between anxious symptoms and GAD with both unipolar and bipolar depression.

METHOD

MDD and bipolar disorder (BPD) are compared in three important respects: the extent of their co-morbidity with anxious symptoms and GAD, the effects that anxiety has on outcome of MDD and BPD, and the effects that anxiety has on the probability of suicide in each disorder.

RESULTS

Anxious diagnoses occur frequently in association with depressive disorders, albeit to a different extent in the various subtypes of depression. In both disorders, anxiety affects the outcome and makes suicidal thoughts, and completed suicide more likely.

CONCLUSIONS

Anxious phenomena should be assessed whenever a depressive disorder is diagnosed. It is likely that the raised expectancy of anxious phenomena is related to an individual's premorbid level of negative affect, and it is possible that suicidal phenomena are related to subthreshold hypomanic symptoms.

Depression in bipolar disorder versus major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions

OBJECTIVES

To compare the clinical features and course of major depressive episodes (MDEs) occurring in subjects with bipolar I disorder (BD-I), bipolar II disorder (BD-II), and major depressive disorder (MDD).

METHODS

Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (2001-2002), a nationally representative face-to-face survey of more than 43000 adults in the USA, including 5695 subjects with lifetime MDD, 935 with BD-I and lifetime MDE, and 494 with BD-II and lifetime MDE. Differences on sociodemographic characteristics and clinical features, course, and treatment patterns of MDE were analyzed.

RESULTS

Most depressive symptoms, family psychiatric history, anxiety disorders, alcohol and drug use disorders, and personality disorders were more frequent-and number of depressive symptoms per MDE was higher-among subjects with BD-I, followed by BD-II, and MDD. BD-I individuals experienced a higher number of lifetime MDEs, had a poorer quality of life, and received significantly more treatment for MDE than BD-II and MDD subjects. Individuals with BD-I and BD-II experienced their first mood episode about ten years earlier than those with MDD (21.2, 20.5, and 30.4 years, respectively).

CONCLUSIONS

Our results support the existence of a spectrum of severity of MDE, with highest severity for BD-I, followed by BD-II and MDD, suggesting the utility of dimensional assessments in current categorical classifications.

Empirically derived subgroups of bipolar I patients with different comorbidity patterns of anxiety and substance use disorders in Han Chinese population

OBJECTIVE

Bipolar-I disorder (BPI) often co-occurred with anxiety (ANX) and substance use disorders (SUD), which poses challenges in public health and clinical treatment, and adds complexity in searching for relevant etiologic factors. The present study sought to identify subgroups of BPI patients using comorbidity patterns with ANX and SUD.

METHODS

Clinical patients (N=306) diagnosed with BPI were recruited and interviewed using the Composite International Diagnostic Interview to collect data on demographics and clinical features, including episodic information, impairments, and lifetime diagnoses of ANX (panic, agoraphobia, generalized anxiety disorder, specific and social phobia) and SUD (nicotine dependence, alcohol use and drug use disorder). We applied latent class analysis to empirically derive classes of BPI. A number of exogenous variables were examined for each class.

RESULTS

A three-class model provides excellent discriminability for subgrouping BPI patients with different comorbidity patterns. The BPI-LOW class (83.99%) had more pure mania without most lifetime comorbidity, higher numbers of last year mania episodes, and less suicidality and impairments. The BPI-ANX class (3.60%) was female predominant, tended to comorbid with multiple anxiety disorders but no SUD, and had early onset age. The BPI-SUD class (12.42%) was male predominant, had high prevalence of lifetime SUD and frequent mood episodes in the last year. Both the BPI-ANX and BPI-SUD classes had severe functional impairments and suicidal behaviors.

LIMITATIONS

Clinical information was retrospectively collected. Besides, we did not comprehensively access lifetime comorbidity for all psychiatric disorders.

CONCLUSION

The three empirically identified subgroups of BPI patients exhibited distinguished comorbidity patterns and clinical features, including suicidal behaviors, frequent mood episodes and functional impairments. Our findings have clinical implication in intervention and treatment as well as to explore their different underlying mechanisms.

Treatment-induced manic switch in the course of unipolar depression can predict bipolarity: cluster analysis based evidence

BACKGROUND

Antidepressants are known to induce manic switch in patients with depression. Treatment-induced mania is not considered as bipolar disorder in DSM IV. The aim of this study was to assess whether clinical characteristics of patients with unipolar depression with a history of treatment-induced mania were similar to those of patients with bipolar disorder.

METHOD

The study included 217 consecutive patients with DSM-IV mood disorders, diagnosed as: bipolar disorder type I (BP-I, n = 58) or type II (BP-II, n = 18) whose first episodes were depression, recurrent (unipolar) major depressive disorder with a history of antidepressant treatment-induced mania (switchers = sUD; n = 61) and without such an event (rUD; n = 80). First, the groups were compared with regard to clinical features and course specifiers using variance and chi-square analysis. Variables that differed significantly between the four groups were included in two-step cluster analysis to explore naturally occurring subgroups in all diagnoses. Subsequently, the relationship between the naturally occurring clusters and pre-defined DSM-IV diagnoses were investigated.

RESULTS

Two-step cluster analysis revealed two different naturally occurring groups. Higher severity of depressive episodes, with higher rate of melancholic features, higher number of hospitalization and suicide attempts were represented in one cluster where switchers (77%), bipolar I (94.8%) and II (83.3%) patients clustered together.

CONCLUSION

The findings of this study confirm that treatment-induced mania is a clinical phenomenon that belongs within the bipolar spectrum rather than a coincidental treatment complication, and that it should be placed under "bipolar disorders" in future classification systems.

LIMITATIONS

The study includes the limitations of any naturalistic retrospective study.

Comparison of depressive episodes in bipolar disorder and in major depressive disorder within bipolar disorder pedigrees

BACKGROUND

Although genetic epidemiological studies have confirmed increased rates of major depressive disorder among the relatives of people with bipolar affective disorder, no report has compared the clinical characteristics of depression between these two groups.

AIMS

To compare clinical features of depressive episodes across participants with major depressive disorder and bipolar disorder from within bipolar disorder pedigrees, and assess the utility of a recently proposed probabilistic approach to distinguishing bipolar from unipolar depression. A secondary aim was to identify subgroups within the relatives with major depression potentially indicative of 'genetic' and 'sporadic' subgroups.

METHOD

Patients with bipolar disorder types 1 and 2 (n = 246) and patients with major depressive disorder from bipolar pedigrees (n = 120) were assessed using the Diagnostic Interview for Genetic Studies. Logistic regression was used to identify distinguishing clinical features and assess the utility of the probabilistic approach. Hierarchical cluster analysis was used to identify subgroups within the major depressive disorder sample.

RESULTS

Bipolar depression was characterised by significantly higher rates of psychomotor retardation, difficulty thinking, early morning awakening, morning worsening and psychotic features. Depending on the threshold employed, the probabilistic approach yielded a positive predictive value ranging from 74% to 82%. Two clusters within the major depressive disorder sample were found, one of which demonstrated features characteristic of bipolar depression, suggesting a possible 'genetic' subgroup.

CONCLUSIONS

A number of previously identified clinical differences between unipolar and bipolar depression were confirmed among participants from within bipolar disorder pedigrees. Preliminary validation of the probabilistic approach in differentiating between unipolar and bipolar depression is consistent with dimensional distinctions between the two disorders and offers clinical utility in identifying patients who may warrant further assessment for bipolarity. The major depressive disorder clusters potentially reflect genetic and sporadic subgroups which, if replicated independently, might enable an improved phenotypic definition of underlying bipolarity in genetic analyses.

A population-based morphometric MRI study in patients with first-episode psychotic bipolar disorder: comparison with geographically matched healthy controls and major depressive disorder subjects

OBJECTIVES

Many morphometric magnetic resonance imaging (MRI) studies that have investigated the presence of gray matter (GM) volume abnormalities associated with the diagnosis of bipolar disorder (BD) have reported conflicting findings. None of these studies has compared patients with recent-onset psychotic BD with asymptomatic controls selected from exactly the same environment using epidemiological methods, or has directly contrasted BD patients against subjects with first-onset psychotic major depressive disorder (MDD). We examined structural brain differences between (i) BD (type I) subjects and MDD subjects with psychotic features in their first contact with the healthcare system in Brazil, and (ii) these two mood disorder groups relative to a sample of geographically matched asymptomatic controls.

METHODS

A total of 26 BD subjects, 20 subjects with MDD, and 94 healthy controls were examined using either of two identical MRI scanners and acquisition protocols. Diagnoses were based on DSM-IV criteria and confirmed one year after brain scanning. Image processing was conducted using voxel-based morphometry.

RESULTS

The BD group showed increased volume of the right dorsal anterior cingulate cortex relative to controls, while the MDD subjects exhibited bilateral foci GM deficits in the dorsolateral prefrontal cortex (p < 0.05, corrected for multiple comparisons). Direct comparison between BD and MDD patients showed a focus of GM reduction in the right-sided dorsolateral prefrontal cortex (p < 0.05, corrected for multiple comparisons) and a trend (p < 0.10, corrected) toward left-sided GM deficits in the dorsolateral prefrontal cortex of MDD patients. When analyses were repeated with scanner site as a confounding covariate the finding of increased right anterior cingulate volumes in BD patients relative to controls remained statistically significant (p=0.01, corrected for multiple comparisons).

CONCLUSIONS

These findings reinforce the view that there are important pathophysiological distinctions between BD and MDD, and indicate that subtle dorsal anterior cingulate abnormalities may be relevant to the pathophysiology of BD.