Presentation and prevalence of PTSD in a bipolar disorder population: A STEP-BD examination

Background

Co-occurring psychiatric diagnoses have a negative impact on quality of life and change the presentation and prognosis of bipolar disorder (BD). To date, comorbidity research on patients with BD has primarily focused on co-occurring anxiety disorders and trauma history; only recently has there been a specific focus on co-occurring PTSD and BD. Although rates of trauma and PTSD are higher in those with bipolar disorder than in the general population, little is known about differences across bipolar subtypes.

Methods

Using the NIMH STEP-BD dataset (N=3158), this study evaluated whether there were baseline differences in the prevalence of PTSD between participants with bipolar disorder I (BDI) and bipolar disorder II (BDII), using the MINI and the Davidson Trauma Scale. Differences in PTSD symptom clusters between patients with BDI and BDII were also evaluated.

Results

A significantly greater proportion of participants with BDI had co-occurring PTSD at time of study entry (Χ²(1)=12.6; p<.001). BDI and BDII subgroups did not significantly differ in re-experiencing, avoidance, or arousal symptoms.

Limitations

The analysis may suggest a correlational relationship between PTSD and BD, not a causal one. Further, it is possible this population seeks treatment more often than individuals with PTSD alone. Finally, due to the episodic nature of BD and symptom overlap between the two disorders, misdiagnosis is possible.

Conclusions

PTSD may be more prevalent in patients with BDI. However, the symptom presentation of PTSD appears similar across BD subtypes. Individuals should be thoroughly assessed for co-occurring diagnoses in an effort to provide appropriate treatment.     

Cognitive performance is impaired in euthymic Chinese patients with Bipolar 1 Disorder

Background

Data from euthymic patients with Bipolar Disorder (BD) has shown cognitive impairment and the notion that sufferers of BD achieve full recovery between illness episodes is questionable. These findings have not been replicated in a Chinese population. The present study examined the cognitive profile of euthymic Chinese patients with Bipolar 1 Disorder (BD-1) and matched healthy control participants.

Methods

Euthymic patients with BD-1 and matched controls (n=104 in total) completed serial measures to assess mood and also completed an IQ test and the Central Nervous System Vital Signs (CNSVS) computerized battery assessing memory (verbal and visual), executive functions, attention, psychomotor and processing speed.

Results

Patients with BD-1 performed worse than controls on all cognitive domains. When using 2 or more scores below the 5th percentile as a cutoff for neurocognitive impairment, 46.2% of the patients with BD-1 and none of the control sample scored in this range (p<.001). Correlational analysis among the illness variables in BD-1 revealed that cognitive performance was inversely correlated with the number of manic episodes and duration of illness.

Limitations

It was not possible to determine the causal relationship between associated illness and performance. The effect of medication on cognitive performance requires further study.

Conclusions

Euthymic Chinese patients with BD-1 demonstrate marked cognitive impairments and these correlated with illness parameters. Cognitive impairment in BD may be independent of language and culture.     

The association of serum oestradiol level, age, and education with cognitive performance in peri- and late postmenopausal women

Objectives

To evaluate whether healthy women show cognitive changes after menopause and whether the possible changes are oestrogen-, age- or education-dependent.

Methods

Forty-eight women, 21 perimenopausal (aged 43–51 years) and 27 late postmenopausal (aged 59–71 years), participated in the study. Verbal and visuomotor functions, visuoconstructive skills, visual and verbal episodic memory as well as attention were evaluated.

Results

Perimenopausal women performed better than postmenopausal women. Serum oestradiol (E₂) level was included in the model in perimenopausal women only given the lack of endogenous oestrogen in postmenopausal women who were also not using hormone therapy (HT). In perimenopausal women, lower E₂ was associated with better visual episodic memory (p < .05), and older age was related to poorer verbal episodic memory (p < .05). In postmenopausal women, more education was associated with better performance in verbal and visuomotor functions, attention as well as verbal episodic memory (p < .05), older age was related to poorer performance in the visuoconstructive test and visual episodic memory (p < .05).

Conclusions

Perimenopausal women had better cognitive performance compared to late postmenopausal women. In perimenopausal women the effect of E₂ was minor. In both groups, age modified cognitive performance, but more so in postmenopausal women. Education did not have any effect on cognitive performance in perimenopausal women, whereas in postmenopausal women education exceeded age as a source of variation. Thus the relevance of education for better cognition was accentuated after menopause.     

Cognitive–linguistic deficits in euthymic elderly patients with bipolar disorder

Background

There is increasing evidence that bipolar disorder is also associated with neuropsychological impairments persisting during euthymia, thus representing a trait-like feature of the disease. Language and speech abnormalities are also present in bipolar disorder, especially in verbal fluency and verbal memory. However, there is a lack of studies in the literature investigating different levels of linguistic processing (phonological, syntactical, and semantic) in a single cohort of euthymic bipolar patients. Based on previous findings of pervasive language impairment in euthymic elderly bipolar patients, the aim of this study was to comprise a more thorough investigation on the subject.

Methods

We studied 19 euthymic bipolar patients aged 60 and above, and 20 cognitively healthy subjects using the Arizona Battery for Communication Disorders of Dementia (ABCD) and the Test for Reception of Grammar Version 2 (TROG-2) in order to assess the phonological, syntactic, and semantic domains of language.

Results

Bipolar patients performed poorer than controls in Linguistic Expression (p=0.011), in Linguistic Comprehension (Following Commands; p=0.025 and Reading Comprehension of Sentences; p=0.007), and in the TROG-2 (p=0.006).

Limitations

The small sample comprising only elderly patients; the lack of statistical power to analyze the potential effect of individual medications on the cognitive performance.

Conclusions

Our data demonstrate that linguistic impairment is present in euthymic bipolar patients, affecting mostly syntactic and lexical–semantic abilities, both in comprehension and production of language. These deficits are interrelated with other cognitive skills also known to be affected in bipolar disorder, such as executive functions and episodic memory.     

Distinct alterations in value-based decision-making and cognitive control in suicide attempters: Toward a dual neurocognitive model

Objective

The literature suggests that many suicide attempters show impairment in both decision-making and cognitive control. However, it is not clear if these deficits are linked to each other, and if they may be related to more basic alterations in attention. This is a relevant question in the perspective of future interventions targeting cognitive deficits to prevent suicidal acts.

Method

Two different populations of patients with histories of suicide attempts were assessed (N=142 and 119). The Iowa Gambling Task (IGT) was used to measure decision-making in both populations. We used a D2 cancellation task and a verbal working memory task in population 1; the Stroop test, the N-Back task, the Trail Making Test, and the Hayling Sentence Completion test in population 2.

Results

Regarding decision-making, we only found a small negative correlation between the Hayling test error score (r=−0.24; p=0.01), and the net score from the second half of the IGT. In contrast, working memory, cognitive flexibility and cognitive inhibition measures were largely inter-correlated.

Limitation

Most patients were medicated. Only patients with mood disorders.

Conclusion

These results add to previous findings suggesting that the neurocognitive vulnerability to suicidal behavior may rely on impairments in two distinct anatomical systems, one processing value-based decision-making (associated with ventral prefrontal cortex, among others) and one underlying cognitive control (associated with more dorsal prefrontal regions). This distinction may result in tailored-made cognitive interventions.     

Posterior cerebellar vermal deficits in bipolar disorder

Background

Based on growing evidence of the crucial role of the cerebellum in emotional regulation, we sought to identify cerebellar structural deficits in a large sample of patients with bipolar disorder (BD).

Methods

Cerebellar gray matter density was examined in 49 BD patients (24 medication-naive and 25 medication-treated) and 50 carefully matched healthy individuals, using voxel-based morphometry with a high-resolution spatially unbiased atlas template of the human cerebellum. This recently developed methodology is specifically optimized for the assessment of cerebellar structures. We further explored whether antimanic treatment could attenuate cerebellar structural deficits.

Results

BD patients showed a greater reduction in gray matter density of the posterior cerebellar regions, including the bilateral vermi and the right crus relative to healthy individuals (corrected p<.05). A stepwise linear reduction in gray matter density was observed in bilateral vermal regions between healthy individuals, medication-treated, and medication-naive BD patients. Furthermore, positive correlations of longer duration of illness with bilateral vermal gray matter deficits were observed only in medication-naive BD patients, but not in patients with medication history.

Limitations

This study adopted a cross-sectional design. The automatic intensity-normalization method for the measurement of cerebellar gray matter density may have a limitation in providing detailed anatomical information at a cerebellar folia level.

Conclusions

The current findings suggest that BD-related deficits in the posterior cerebellar regions, which appear to progress over the course of illness, could potentially be ameliorated by proper treatment with mood stabilizers.     

Altered explicit recognition of facial disgust associated with predisposition to suicidal behavior but not depression

Background

Suicidal acts result from a complex interplay between vulnerability factors, such as reduced social and cognitive abilities, social stressors. To our knowledge nothing is known about the explicit recognition of others' facial emotions, a major component of social interactions, in patients at long-term risk for suicide.

Methods

Thirty-five non-depressed patients with a history of a serious suicide attempt and mood disorders were compared with 31 patients with a history of mood disorders but no personal history of suicidal acts, and with 37 healthy controls with no personal history of mood disorders or suicide attempts. The explicit recognition of six facial emotions (anger, disgust, fear, sadness, happiness, and neutral) was assessed.

Results

Suicide attempters made significantly more errors in the explicit recognition of disgust, relative to the other groups, with no differences between the control groups or for the other emotions examined. Semantic verbal fluency and verbal working memory performances were also reduced in suicide attempters relative to the other two groups but could not explain the facial recognition deficits.

Limitations

Our results need replication with a larger sample size. Most patients were medicated.

Conclusions

Explicit recognition of disgust appears to be specifically altered in relation to vulnerability to suicide but not to depression. Reduced ability to recognize some social emotions may impair the patient's capacity to adequately interact with his own social environment, potentially increasing the risk of interpersonal conflict, negative emotions and suicidal crisis. Improving cognitive and social skills may be a target for future individual suicide prevention.     

Quantitative EEG in Alzheimer's disease: Cognitive state,resting state and association with disease severity

Background

Quantitative electroencephalogram (qEEG) recorded during cognitive tasks has been shown to differentiate between patients with Alzheimer's disease (AD) and healthy individuals. However, the association between various qEEG markers recorded during mnestic paradigms and clinical measures of AD has not been studied in detail.

Objective

To evaluate if ‘cognitive’ qEEG is a useful diagnostic option, particularly if memory paradigms are used as cognitive stimulators.

Methods

This study is part of the Prospective Registry on Dementia in Austria (PRODEM), a multicenter dementia research project. A cohort of 79 probable AD patients was included in a cross-sectional analysis. qEEG recordings performed in resting states were compared with recordings during cognitively active states. Cognition was evoked with a face–name paradigm and a paired-associate word list task, respectively. Relative band powers, coherence and auto-mutual information were computed as functions of MMSE scores for the memory paradigms and during rest. Analyses were adjusted for the co-variables age, sex, duration of dementia and educational level.

Results

MMSE scores explained 36–51% of the variances of qEEG-markers. Face–name encoding with eyes open was superior to resting state with eyes closed in relative theta and beta1 power as well as coherence, whereas relative alpha power and auto-mutual information yielded more significant results during resting state with eyes closed. The face–name task yielded stronger correlations with MMSE scores than the verbal memory task.

Conclusion

qEEG alterations recorded during mnestic activity, particularly face–name encoding showed the highest association with the MMSE and may serve as a clinically valuable marker for disease severity.     

Homocysteine,depression and cognitive function in older adults

Background

Depression and high total plasma homocysteine (tHcy) are independently associated with cognitive impairment in older adults. We designed this study to determine if high tHcy is a mediator of cognitive performance in older adults with major depression.

Methods

We recruited 358 community-dwelling older adults experiencing depressive symptoms, 236 (65.9%) of who met DSM-IV-TR criteria for major depression. Assessment included the Montgomery Asberg Depression Rating Scale (MADRS), fasting tHcy and the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery.

Results

Individuals with major depression and high tHcy had significantly worse immediate verbal and delayed visual recall. Non-depressed participants with high tHcy had lower MMSE, immediate and delayed recall scores than those with normal tHcy. The odds of cognitive inefficiency for those with high tHcy was nearly doubled for the MMSE (OR 1.9, 95%CI 1.1–3.3), immediate (OR 1.9, 95%CI 1.1–3.5) and delayed (OR 1.9, 95%CI 1.1–3.4) word recall after adjusting for age, gender, IHD and MADRS score.

Limitations

The presence of sub-syndromal depressive symptoms in our non-depressed group and exclusion of participants with established cognitive impairment may limit the generalizability of this study.

Conclusions

Elevated tHcy was associated with weaker performance in tests of immediate and delayed memory and global cognitive performance when compared to those with normal tHcy independent of the presence of major depression or the severity of depressive symptoms. Homocysteine lowering B-vitamin supplementation may offer a potential therapeutic target to try and mitigate the often-disabling impact of cognitive deficits found in this population.     

Validity and reliability of a rating scale on subjective cognitive deficits in bipolar disorder (COBRA)

Background

Discrepancies between bipolar patients' reports and neuropsychological testing have been described and replicated. Unfortunately, no valid, specific, user-friendly, brief instrument is available to measure cognitive deficits as reported by these patients. The main aim of this study was to validate a novel instrument named the “cognitive complaints in bipolar disorder rating assessment” (COBRA). Second, we investigated the relationship between the COBRA, objective cognitive measures and illness course variables.

Method

The total sample (N=215) included 91 bipolar disorder patients and 124 healthy controls. The psychometric properties of the COBRA (e.g. internal consistency, concurrent validity, discriminative validity, factorial analyses, ROC curve and feasibility) were analyzed. A complete neuropsychological battery was used as objective cognitive assessment.

Results

The COBRA had one-factor structure with very high internal consistency (Cronbach's alpha=0.913). A high convergent validity was indicated by a strong correlation with the Frankfurt Complaint Questionnaire (ro=0.888, p<0.001). Bipolar patients experienced greater cognitive complaints compared to control group suggesting a discriminative validity of the instrument. Significant correlations were found between the COBRA and some objective cognitive measures. Furthermore, higher COBRA scores were associated with bipolar II subtype, residual depressive symptoms, hypomanic episodes and total episodes.

Limitations

The cross-sectional design of the study, the influence of medication and severity of patients included.

Conclusions

The COBRA showed to be a useful instrument to assess overall cognitive complaints in bipolar disorder with very satisfactory psychometric properties. Cognitive complaints were partially correlated with memory and executive function measures and with issues that may increase the subjective perception of cognitive deficits, such as subthreshold depressive symptoms and number of episodes.     

Verbal communication among Alzheimer's disease patients, their caregivers, and primary care physicians during primary care office visits

Objective

Primary care visits of patients with Alzheimer's disease (AD) often involve communication among patients, family caregivers, and primary care physicians (PCPs). The objective of this study was to understand the nature of each individual's verbal participation in these triadic interactions.

Methods

To define the verbal communication dynamics of AD care triads, we compared verbal participation (percent of total visit speech) by each participant in patient/caregiver/PCP triads. Twenty-three triads were audio taped during a routine primary care visit. Rates of verbal participation were described and effects of patient cognitive status (MMSE score, verbal fluency) on verbal participation were assessed.

Results

PCP verbal participation was highest at 53% of total visit speech, followed by caregivers (31%) and patients (16%). Patient cognitive measures were related to patient and caregiver verbal participation, but not to PCP participation. Caregiver satisfaction with interpersonal treatment by PCP was positively related to caregiver's own verbal participation.

Conclusion

Caregivers of AD patients and PCPs maintain active, coordinated verbal participation in primary care visits while patients participate less.

Practice implications

Encouraging verbal participation by AD patients and their caregivers may increase the AD patient's active role and caregiver satisfaction with primary care visits.     

In your eyes: Does theory of mind predict impaired life functioning in bipolar disorder?

Background

Deficits in emotion perception and social functioning are strongly implicated in bipolar disorder (BD). Examining theory of mind (ToM) may provide one potential mechanism to explain observed socio-emotional impairments in this disorder. The present study prospectively investigated the relationship between theory of mind performance and life functioning in individuals diagnosed with BD compared to unipolar depression and healthy control groups.

Methods

Theory of mind (ToM) performance was examined in 26 individuals with remitted bipolar I disorder (BD), 29 individuals with remitted unipolar depression (UD), and 28 healthy controls (CTL) using a well-validated advanced theory of mind task. Accuracy and response latency scores were calculated from the task. Life functioning was measured during a 12 month follow-up session.

Results

No group differences for ToM accuracy emerged. However, the BD group exhibited significantly shorter response times than the UD and CTL groups. Importantly, quicker response times in the BD group predicted greater life functioning impairment at a 12-month follow-up, even after controlling for baseline symptoms.

Limitations

The stimuli were static representations of emotional states and do not allow for evaluating the appropriateness of context during emotional communication; due to sample size, neither specific comorbidities nor medication effects were analyzed for the BD and UD groups; preliminary status of theory of mind as a construct.

Conclusions

Results suggest that quickened socio-emotional decision making may represent a risk factor for future functional impairment in BD.     

Neural mechanisms of cognitive reappraisal in remitted major depressive disorder

Background

Down-regulation of negative emotions by cognitive strategies relies on prefrontal cortical modulation of limbic brain regions, and impaired frontolimbic functioning during cognitive reappraisal has been observed in affective disorders. However, no study to date has examined cognitive reappraisal in unmedicated euthymic individuals with a history of major depressive disorder relative to symptom-matched controls. Given that a history of depression is a critical risk factor for future depressive episodes, investigating the neural mechanisms of emotion regulation in remitted major depressive disorder (rMDD) may yield novel insights into depression risk.

Method

We assessed 37 individuals (18 rMDD, 19 controls) with functional magnetic resonance imaging (fMRI) during a task requiring cognitive reappraisal of sad images.

Results

Both groups demonstrated decreased self-reported negative affect after cognitive reappraisal and no group differences in the effects of cognitive reappraisal on mood were evident. Functional MRI results indicated greater paracingulate gyrus (rostral anterior cingulate cortex, Brodmann area 32) activation and decreased right midfrontal gyrus (Brodmann area 6) activation during the reappraisal of sad images.

Limitations

Trial-by-trial ratings of pre-regulation affect were not collected, limiting the interpretation of post-regulation negative affect scores.

Conclusions

Results suggest that activation of rostral anterior cingulate cortex, a region linked to the prediction of antidepressant treatment response, and of the right midfrontal gyrus, a region involved in cognitive control in the context of cognitive reappraisal, may represent endophenotypic markers of future depression risk. Future prospective studies will be needed to validate the predictive utility of these neural markers.     

Time course for memory dysfunction in early-life and late-life major depression: A longitudinal study from the Juntendo university mood disorder project

Background

Previous studies have demonstrated that patients with depression also have memory dysfunctions during depressive episodes. These dysfunctions partially remain immediately after remission from a depressive state; however, it is unclear whether these residual memory dysfunctions may disappear through long-term remission from depression. The present study compared patients during early-life (age<60) and late-life (age≥60) depression while in their remitted stage with healthy controls to elucidate the impact of a long-term course on memory.

Methods

Logical memory from the Wechsler Memory Scale-Revised was administered to 67 patients with major depressive disorder (MDD) (47 patients with early-life depression and residual 20 patients with late-life depression) and 50 healthy controls. MDD patients received memory assessments at the time of their initial remission and at a follow-up three years after remission.

Results

At the time of initial remission, scores for logical memory were significantly lower in both patient groups compared to matched controls. At follow-up, memory dysfunction for early-life MDD patients disappeared, whereas scores in the late-life MDD group remained significantly lower than those of matched controls.

Limitations

All patients in the present study were on antidepressant medications.

Conclusions

Our findings suggested that the progress of memory performance in late-life MDD patients may be different from early-life MDD patients.     

Elevated C-reactive protein and cognitive deficits in individuals with bipolar disorder

Background

Some individuals with bipolar disorder have cognitive deficits even when euthymic. In previous studies, we found an association between elevated levels of C-reactive protein (CRP), a marker of inflammation, and reduced cognitive functioning in schizophrenia. This issue has not been examined in bipolar disorder.

Methods

We measured the levels of high sensitivity CRP in serum samples from 107 individuals with bipolar disorder. Cognitive functioning was measured with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Trail Making Test Part A and WAIS Information and Letter Number Sequencing. We estimated the odds of RBANS scores <=70 for participants whose CRP levels were above the 75th and the 90th percentile of the level of non-psychiatric controls. We also examined the association between cognitive scores and CRP levels. Covariates included demographic factors, mood symptom severity, cigarette smoking status, and body mass index.

Results

There was a significantly increased odds of low RBANS total score for individuals who had a CRP level higher than the 90th percentile (OR=4.32, p=.018) and the 75th percentile (OR=3.07, p=.04)) of the control group. There was an inverse relationship between CRP levels and performance on RBANS total (t=−2.48, p=.015); RBANS immediate memory (t=−2.16, p=.033); RBANS attention (t=−2.18, p=.032); RBANS language (t=−2.13, p=.036); Trail Making A (t=−2.39, p=.019).

Limitations

Factors which we did not measure such as diet, allergen exposure, and underlying autoimmune disorders may contribute to CRP levels.

Conclusions

Inflammation may play a major role in the cognitive deficits associated with bipolar disorder.     

The influence of vascular risk factors on cognitive decline in patients with Alzheimer's Disease

Introduction

The influence of vascular risk factors (VRFs) on the rate of cognitive decline in patients with established dementia is unclear. This study aims to examine the association between VRFs and the rate of cognitive decline in patients with Alzheimer's disease (AD).

Methods

Data were obtained from patients visiting a memory clinic between 2004 and 2012. VRFs were determined at baseline and included hypertension, hypercholesterolemia, diabetes mellitus, overweight and smoking. Continuous values of blood pressure, total cholesterol, glucose level and body mass index were also obtained. Mini-Mental State Exam (MMSE) scores were obtained at baseline and during follow-up visits. The association between VRFs and the annual change in MMSE scores was analysed with a multivariable linear mixed model adjusted for age, sex and the aforementioned VRFs.

Results

From 174 patients (mean age 78.3 years), with a follow-up time up to 5.8 years (mean 1.1 year), in total 447 MMSE scores were obtained. The multivariable analyses showed an association between age as well as systolic blood pressure and a decline in annual rates of change in MMSE scores of −0.05 (95% confidence interval (CI): −0.09 to 0.00) and −0.01 (CI: −0.03 to 0.00), respectively. For all other VRFs, including sex, patients did not show a significant difference.

Conclusion

This study did not find an association between preventable vascular risk factors and cognitive decline in patients with AD, except for systolic blood pressure. As the association between systolic blood pressure and decline in MMSE was small, clinical relevance may be limited.     

Working memory and the design of health materials: A cognitive factors perspective

Objective

Working memory and other supportive cognitive processes involved in learning are reviewed in the context of developing patient education materials. We specifically focus on the impact of certain design factors such as text format and syntax, the inclusion of images, and the choice of modality on individuals’ ability to understand and remember health information.

Methods

A selective review of relevant cognitive and learning theories is discussed with regard to their potential impact on the optimal design of health materials.

Results

Working memory is measured as an individual's capacity to hold and manipulate information in active consciousness. It is limited by necessity, and well-designed health materials can effectively minimize extraneous cognitive demands placed on individuals, making working memory resources more available to better process content-related information.

Conclusions

Further research is needed to evaluate specific design principles and identify ideal uses of print versus video-based forms of communication for conveying information.

Practice implications

The process of developing health materials should account for the cognitive demands that extrinsic factors such as modality place on patients.     

Further validation of the Patient-Practitioner Orientation Scale (PPOS) from recorded visits for back pain

Objective

More patient-centered communication is associated with improved patient satisfaction and health status, fewer malpractice complaints, and increased adherence. In a study of medical encounters for acute low back pain (LBP), we conducted a secondary analysis to assess the validity of the Patient Practitioner Orientation Scale (PPOS), a measure of patient-centeredness.

Methods

Fourteen clinicians and 89 of their patients with acute LBP completed the PPOS and agreed to have verbal exchanges recorded and coded using the Roter Interaction Analysis System (RIAS). We examined correlations between the PPOS and counts of patient and provider utterances within 8 RIAS verbal exchange categories.

Results

Providers with a more patient-centered orientation asked fewer biomedical questions, posed more lifestyle questions, gave more lifestyle advice, and did more rapport-building. Their patients shared more lifestyle information and made more attempts at rapport building and provider engagement. In contrast, the patient-centered orientation of patients showed no effect on communication.

Conclusion

The PPOS scores of providers, but not patients, predicted significant and meaningful differences in the verbal exchanges of patients and providers.

Practice implications

The results support the validity of the PPOS measure and provide further evidence of the extent to which provider orientation influences patient communication and exchange.     

Differences in functional connectivity in major depression versus bipolar II depression

Background

Objective methods of differentiating unipolar versus bipolar depression would enhance our ability to treat these disorders by providing more accurate diagnoses. One first step towards developing diagnostic methodology is determining whether brain function as assessed by functional MRI (fMRI) and functional connectivity analyses might differentiate the two disorders.

Methods

Fourteen subjects with bipolar II depression and 26 subjects with recurrent unipolar depression were studied using fMRI and functional connectivity analyses.

Results

The first key finding of this study was that functional connectivity of the right posterior cingulate cortex differentiates bipolar II and unipolar depression. Additionally, results suggest that functional connectivity of this region is associated with suicidal ideation and depression severity in unipolar but not bipolar II depression.

Limitations

The primary limitation is the relatively small sample size, particularly for the correlational analyses.

Conclusions

The functional connectivity of right posterior cingulate cortex may differential unipolar from bipolar II depression. Further, connectivity of this region may be associated with depression severity and suicide risk in unipolar but not bipolar depression.