Diagnostic conversions from major depressive disorder into bipolar disorder in an outpatient setting: results of a retrospective chart review

Antidepressant-associated diagnostic change from major depressive to bipolar disorder

BACKGROUND

Anticipating diagnostic change from major depressive (MDD) to bipolar disorder (BD) can support better prognosis and treatment, especially of depression but is challenging and reported research results are inconsistent. We therefore assessed clinical characteristics associated with diagnostic change from MDD to BD with antidepressant treatments.

METHODS

We compared characteristics of 3212 initially MDD patients who became (hypo)manic during antidepressant treatment to those with stable MDD diagnoses as well as with cases of stable, spontaneous BD, using standard bivariate and multivariate statistics.

RESULTS

Among MDD patients, 6.69% [CI: 5.85-7.61] changed to BD, mostly type II (BD2, 76.7%). BD-converters had higher rates of familial mood disorders (74.1% vs. 57.1%) or BD (33.7% vs. 21.0%) and 2.8-years younger onset than stable MDD patients. They also had more prior depressive recurrences/year, years-of-illness, mood-stabilizer treatment, divorces, fewer children, more suicide attempts and drug-abuse, and higher intake cyclothymia, YMRS and MDQ scores. Predictors independently associated with diagnostic conversion were: more familial BD, depressions/year, unemployment, cyclothymic temperament, suicidal ideation or acts, and fewer children. BD-converters vs. spontaneous BD cases had significantly more suicide attempts, BD2 diagnoses, and affected relatives. Converting to vs. spontaneous BD1 was associated with more ADHD, more suicidal ideation or behavior, MDI course, and younger onset; converting to vs. spontaneous BD2 had more episodes/year, unemployment, ADHD, substance abuse, suicidal ideation or attempts, and more relatives with BD.

CONCLUSIONS

Few (6.69%) initially MDD subjects converted to BD, most (76.7%) to BD2. Independent predictive associations with diagnostic change included: familial BD, more depressions/year, unemployment, cyclothymic temperament, suicidal behavior and fewer children. Notably, several characteristics were stronger among those changing to BD during antidepressant treatment vs. others with spontaneous BD.

Predictors of diagnostic conversion from major depression to bipolar disorder: a Swedish national longitudinal study

BACKGROUND

It is clinically important to predict the conversion of major depression (MD) to bipolar disorder (BD). Therefore, we sought to identify related conversion rates and risk factors.

METHODS

This cohort study included the Swedish population born from 1941 onward. Data were collected from Swedish population-based registers. Potential risk factors, including family genetic risk scores (FGRS), which were calculated based on the phenotypes of relatives in the extended family and not molecular data, and demographic/clinical characteristics from these registers were retrieved. Those with first MD registrations from 2006 were followed up until 2018. The conversion rate to BD and related risk factors were analyzed using Cox proportional hazards models. Additional analyses were performed for late converters and with stratification by sex.

RESULTS

The cumulative incidence of conversion was 5.84% [95% confidence interval (95% CI) 5.72-5.96] for 13 years. In the multivariable analysis, the strongest risk factors for conversion were high FGRS of BD [hazard ratio (HR) = 2.73, 95% CI 2.43-3.08], inpatient treatment settings (HR = 2.64, 95% CI 2.44-2.84), and psychotic depression (HR = 2.58, 95% CI 2.14-3.11). For late converters, the first registration of MD during the teenage years was a stronger risk factor when compared with the baseline model. When the interactions between risk factors and sex were significant, stratification by sex revealed that they were more predictive in females.

CONCLUSIONS

Family history of BD, inpatient treatment, and psychotic symptoms were the strongest predictors of conversion from MD to BD.

Sex effects on differentiating patients with major depressive disorder from bipolar disorder in depressive state: A fMRI study with follow-up

BACKGROUND

Bipolar disorder (BD) is difficult to discriminate from major depressive disorder (MDD) before the appearance of mania or hypomania. This study was designed to identify whether patients with MDD and those who converted to BD are distinguishable using dynamic amplitude low-frequency fluctuations (dALFF) and describe the sex effects on the identification of the two disorders.

METHODS

We compared the dALFF values of 35 BD patients who converted from MDD during the 2-year follow-up, 99 MDD patients, and 130 healthy controls (HCs) using two-way ANOVA. Pearson's correlation was used to compare dALFF in dysfunctional brain regions and clinical characteristics.

RESULTS

A main effect of diagnosis was discovered in the frontal and occipital gyrus. For the main effect of sex, both the left middle occipital gyrus and the medial part of the superior frontal gyrus had higher dALFF values in males compared to females. An interaction of sex and diagnosis effect was observed in the right precentral gyrus. Male MDD patients exhibited a higher dALFF value than male BD patients. Additionally, we discovered a higher dALFF value in females than in males in BD patients. WCST scores were positively associated with dALFF values in the frontal and occipital gyrus in MDD patients. Meanwhile, dALFF values in the occipital gyrus positively correlated with WCST in female MDD patients only.

LIMITATION

Most of the participants were on medication and the sample size was small.

CONCLUSIONS

Our study is the first to find the non-neglectable role of sex effects in differentiating BD and MDD at an early stage.

Taiwan consensus on biological treatment of bipolar disorder during the acute, maintenance, and mixed phases: The 2022 update

BACKGROUND

Bipolar disorder is a mood dysregulation characterized by recurrent symptoms and episodes of mania, hypomania, depression, and mixed mood. The complexity of treating patients with bipolar disorder prompted the Taiwanese Society of Biological Psychiatry and Neuropsychopharmacology (TSBPN) to publish the first Taiwan consensus on pharmacological treatment of bipolar disorders in 2012. This paper presents the updated consensus, with changes in diagnostic criteria (i.e., mixed features) and emerging pharmacological evidence published up to April 2022.

METHODS

Our working group systemically reviewed the clinical research evidence and international guidelines and determined the levels of evidence for each pharmacological treatment on the basis of the most recent World Federation of Societies of Biological Psychiatry grading system. Four clinical-specific issues were proposed. The current TSBPN Bipolar Taskforce then discussed research evidence and clinical experience related to each treatment option in terms of efficacy and acceptability and then appraised final recommendation grades through anonymous voting.

RESULTS

In the updated consensus, we include the pharmacological recommendations for bipolar disorder with mixed features considering its high prevalence, the severe clinical prognosis, and the absence of approved medications. Cariprazine, lurasidone, repetitive transcranial magnetic stimulation, and ketamine are incorporated as treatment options. In the maintenance phase, the application of long-acting injectable antipsychotics is emphasized, and the hazards of using antidepressants and conventional antipsychotics are proposed.

CONCLUSIONS

This updated Taiwan consensus on pharmacological treatment for bipolar disorder provides concise evidence-based and empirical recommendations for clinical psychiatric practice. It may facilitate treatment outcome improvement in patients with bipolar disorder.

Risk of conversion to bipolar disorder in patients with late-onset major depression

To evaluate the impact of age at onset on late-life depression course and on risk of conversion to bipolar disorder (BD). A retrospective chart review of 100 elderly patients (age ≥ 65 years) diagnosed with a moderate-to-severe depressive episode and followed up for at least 18 months was conducted. Among patients affected by major depressive disorder ( N = 57), follow-up morbidity differences between those with typical onset depression (TOD) (<60 years) and those with late-onset depression (LOD) (≥60 years) were investigated using Wilcoxon rank-sum test and Cox proportional hazard model. Patients belonging to the LOD group had a significantly lower percentage of follow-up time spent with depressive symptoms compared with patients with TOD ( r = 0.36; P = 0.006), but significantly more time spent with (hypo)manic episodes ( r = -0.31; P = 0.021). Moreover, LOD was significantly associated with a faster conversion to BD (hazard ratio = 3.05; P = 0.037). Depression first emerging in late life may represent an unstable condition with a high risk to convert to BD. Given the potential clinical implications, further studies on the course of LOD are required.

Interleukin-8 and tumor necrosis factor-alpha in youth with mood disorders-A longitudinal study

Bipolar disorder (BD) is one of the most disabling psychiatric illnesses. Over half of BD patients experienced early onset of the disease, and in most cases, it begins with a depressed mood episode. Up to 50% of adolescents initially diagnosed with major depressive disorder (MDD) convert to bipolar spectrum disorder. Diagnostic tools or biomarkers to facilitate the prediction of diagnosis conversion from MDD to BD are still lacking. Our study aimed to find biomarkers of diagnosis conversion in young patients with mood disorders. We performed a 2-year follow-up study on 69 adolescent patients diagnosed with MDD or BD. The control group consisted of 31 healthy youths. We monitored diagnosis change from MDD to BD. Impulsiveness was assessed using Barratt Impulsiveness Scale (BIS-11) and defense mechanisms using Defense Style Questionnaire (DSQ-40). According to the immunological hypothesis of mood disorders, we investigated baseline cytokines levels either in depressive or hypomanic/manic episodes. We correlated interleukin 8 (IL-8) and Tumor Necrosis Factor-alpha (TNF-alpha) levels with clinical factors. We detected higher IL-8 and TNF-alpha in patients in hypomanic/manic compared to depressed episodes. We found correlations of cytokine levels with immature defense style. We did not discover predictors of diagnosis conversion from MDD to BD.

A Predictive Model of Risk Factors for Conversion From Major Depressive Disorder to Bipolar Disorder Based on Clinical Characteristics and Circadian Rhythm Gene Polymorphisms

BACKGROUND

Bipolar disorder (BD) is easy to be misdiagnosed as major depressive disorder (MDD), which may contribute to a delay in treatment and affect prognosis. Circadian rhythm dysfunction is significantly associated with conversion from MDD to BD. So far, there has been no study that has revealed a relationship between circadian rhythm gene polymorphism and MDD-to-BD conversion. Furthermore, the prediction of MDD-to-BD conversion has not been made by integrating multidimensional data. The study combined clinical and genetic factors to establish a predictive model through machine learning (ML) for MDD-to-BD conversion.

METHOD

By following up for 5 years, 70 patients with MDD and 68 patients with BD were included in this study at last. Single nucleotide polymorphisms (SNPs) of the circadian rhythm genes were selected for detection. The R software was used to operate feature screening and establish a predictive model. The predictive model was established by logistic regression, which was performed by four evaluation methods.

RESULTS

It was found that age of onset was a risk factor for MDD-to-BD conversion. The younger the age of onset, the higher the risk of BD. Furthermore, suicide attempts and the number of hospitalizations were associated with MDD-to-BD conversion. Eleven circadian rhythm gene polymorphisms were associated with MDD-to-BD conversion by feature screening. These factors were used to establish two models, and 4 evaluation methods proved that the model with clinical characteristics and SNPs had the better predictive ability.

CONCLUSION

The risk factors for MDD-to-BD conversion have been found, and a predictive model has been established, with a specific guiding significance for clinical diagnosis.

Relationships of affective temperament ratings to diagnosis and morbidity measures in major affective disorders

BACKGROUND

Ratings of affective temperament types show promise in helping to differentiate diagnostic groups among major affective disorders as well as to predict associations with important aspects of morbidity including suicidal risk.

METHODS

The Temperament Evaluation of Memphis, Pisa, Paris, and San Diego auto-rating (TEMPS-A) questionnaire was completed by 858 unselected, consecutive, consenting adults diagnosed with a DSM-5 major affective disorder (173 bipolar-1 [BD-1]), 250 BD-2, 435 major depressive disorder [MDD]) to score for anxious (anx), cyclothymic (cyc), dysthymic (dys), hyperthymic (hyp), and irritable (irr) affective temperaments. We tested their associations with diagnosis and selected clinical factors, including diagnosis, depression scores, suicidal ideation or acts, substance abuse, episodes/year, and %-time ill.

RESULTS

Scores for cyc ranked: BD-2 > BD-1 > MDD; anx ranked: MDD > BD-2 > BD-1; irr was greater in BD than MDD; dys was greater in MDD than BD; hyp did not differ by diagnosis. We confirmed associations of suicidal risk with higher scores of all temperament types except lower hyp scores. Higher cyc and irr scores and lower anx scores were associated with substance abuse. Several scores were higher with measures of greater affective morbidity: cyc with current depression, episodes/year, and %-time ill; irr with more episodes and depressions/year and greater %-time manic. Some of these associations were selective for BD or MDD.

CONCLUSIONS

The findings indicate that TEMPS-A ratings of affective temperament types can contribute to differential diagnoses and predict types and amounts of affective morbidity, as well as detecting suicidal risks.

Elevated Epidermal Growth Factor (EGF) as Candidate Biomarker of Mood Disorders-Longitudinal Study in Adolescent and Young Adult Patients

Bipolar disorder (BD) is a chronic mental disorder that affects more than 1% of the population worldwide. Over 65% of patients experience early onset of the disease. Most cases of juvenile bipolar disorder begin with a depressed mood episode, and up to 50% of youth initially diagnosed with major depression go onto developing a BD. Our study aimed to find biomarkers of diagnosis conversion in young patients with mood disorders. We performed a two-year follow-up study on 79 adolescent patients diagnosed with MDD or BD, with a detailed clinical assessment at five visits. We monitored diagnosis change from MDD to BD. The control group consisted of 31 healthy youths. According to the neurodevelopmental and neuroimmunological hypotheses of mood disorders, we analyzed serum levels of brain-derived neurotrophic factor (BDNF), proBDNF, epidermal growth factor (EGF), migration inhibitory factor (MIF), stem cell factor (SCF), and correlations with clinical factors. We detected a significant disease-dependent increase in EGF level in MDD and BP patients at baseline exacerbation of depressive or hypomanic/manic episodes as well as in euthymic state compared to healthy controls. No potential biological predictors of disease conversion were found. Replication studies on a larger cohort of patients are needed.

Cognitive complaints in individuals recently diagnosed with bipolar disorder: A cross-sectional study

AIM

To assess the differences in subjective cognitive dysfunction between major depressive disorder (MDD) and recently diagnosed Bipolar Disorder (BD) across euthymia and mood episodes.

METHODS

This is a cross-sectional study corresponding to the second wave of a longitudinal study. The first wave consisted of subjects aged between 18 and 60 diagnosed with MDD. In the follow up after three years (second wave), conversion from MDD to BD diagnosis was assessed by qualified psychologists using the Mini International Neuropsychiatric Interview (MINI-Plus). Subjects were categorized in four diagnostic groups: euthymic MDD, MDD in a current mood episode, euthymic BD, and BD in a current mood episode. All subjects completed the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA), an instrument specifically designed for detecting subjective cognitive deficits in BD.

RESULTS

The total sample (n = 468) included 410 subjects with MDD and 58 individuals recently diagnosed with BD. We subdivided the 2 groups based on their current mood state, and found a significant difference in COBRA total scores between euthymic BD individuals (median 17.00 [IQR: 8.75 - 20.75]) and euthymic MDD subjects (median 8.00 [IRQ: 5.00 - 14.00], p = 0.002), showing higher subjective cognitive dysfunction in individuals recently diagnosed with BD. The differences remained significant after adjusting for the presence of lifetime psychotic symptoms. We found no differences between MDD and BD during an acute mood episode.

LIMITATION

The small sample size of individuals with BD.

CONCLUSION

The findings suggest a higher presence of subjective cognitive complaints among individuals recently diagnosed with BD in comparison to individuals with MDD during euthymia.

Diagnostic conversion to bipolar disorder in unipolar depressed patients in Hong Kong: A 20-year follow-up study

BACKGROUND

Bipolar (BP) disorder, especially BP depression is common and yet remains enigmatic until the emergence of mania. The rates and risk factors of conversion from unipolar (UP) depression to BP disorder reported vary.

OBJECTIVE

To study the long-term conversion rate from UP depression to BP disorder of an inpatient sample and identify the associated risk factors.

METHODS

This is a retrospective longitudinal study conducted in 2017 based on review of medical records of patients admitted to a regional hospital in Hong Kong with diagnosis of major depressive disorder during the period from 1988 to 2000.

RESULTS

A total of 19.5% of subjects had diagnostic shift from UP depression to BP disorder at follow-up, with a mean conversion time of 10.8 years and about 1% shift annually in the first 10 years. Risk factors include family history of mental illness, young age at onset, repeated admissions, psychotic symptoms and use of electroconvulsive therapy. More unconverted UP subjects (9.0%) committed suicide than those converted to BP (3.5%).

LIMITATIONS

The study is limited by its retrospective design.

CONCLUSIONS

Conversion from UP depression to BP disorder is dictated by its biological characteristics and clinical severity. Vigilance should be held in the first decade after onset when most conversion takes place.

Predictors of conversion from major depressive disorder to bipolar disorder

The present study has two main aims: (1) To assess whether childhood trauma helps to differentiate Major Depressive Disorder (MDD) from Bipolar Disorder (BD) in a cross-sectional design; and (2) Describe the rate of conversion from MDD to BD, as well as the clinical and demographic predictors of conversion from MDD to BD in a prospective cohort design. We conducted a prospective cohort study in two phases, in the city of Pelotas, RS, Brazil. In the first phase, 565 subjects diagnosed with MDD, and 127 with BD according to the Mini International Neuropsychiatric Interview were included. In the second phase, only individuals with MDD were reevaluated for potential conversion to BD. The rate of conversion from MDD to BD in 3 years was 12.4%. Predictors of conversion from MDD to BD included lower educational level, use of illicit substances, younger age of the first depressive episode, and family history of BD. Childhood trauma was not a significant risk factor for conversion to BD in our prospective study. Our findings can contribute to the prevention and identification of conversion from MDD to BD, as well as to the establishment of more targeted therapeutic interventions, improving the prognosis of these individuals.

Clinical features and patterns of psychopharmacological prescription in bipolar patients with vs without anxiety disorders at onset

AIM

Up to just over half of bipolar disorder (BD) patients report at least one-lifetime anxiety disorder (AD). In some, anxiety represents the earliest psychiatric manifestation, prior to any mood episode. We sought to investigate prevalence of AD subtypes as first psychiatric manifestations and AD's relations with duration of untreated illness (DUI) and treatment among BD outpatients.

METHODS

We recruited patients referred to the Centre for the Treatment of Depressive Disorders in Milan, diagnosed with BD-I, BD-II, BD not otherwise specified (BD-NOS) and cyclothymia according to Diagnostic and Statistical Manual fourth edition-text revision criteria. Several clinical characteristics were assessed through retrospective chart review and/or direct patient interviews. Based on presence/absence of an AD at psychiatric onset, eligible subjects were stratified into two groups (A+ and A-) and clinical features were compared between these groups and between BD subtypes.

RESULTS

We analysed 260 BD patients (77 BD-I, 122 BD-II, 45 BD-NOS and 16 cyclothymia). An AD was the first psychiatric manifestation in 69 patients (26.5%). BD-II and BD-NOS more frequently had an AD at psychiatric onset, with panic disorder being the most common AD. Among A+ vs A-, age at BD onset was younger, duration of untreated BD illness (DUI) was longer, and a mood stabilizer/antipsychotic was less often prescribed at psychiatric onset.

CONCLUSIONS

Considering BD in its longitudinal course, over one in four BD patients presenting with an AD at psychiatric onset belatedly access adequate treatment, with subsequent prolonged DUI and prospective worse outcome compared to patients with a mood episode at psychiatric onset.

Neurophysiological markers of attention distinguish bipolar disorder and unipolar depression

BACKGROUND

Attentional deficits are common in both symptomatic and symptom-remitted patients with bipolar disorder (BP) and major depressive disorder (MDD). However, whether the level of neurocognitive impairment in attentional processing is different between these two disorders, or not, is still unclear. Thus, we investigated the P300 event-related potential component as a biomarker of cognitive dysfunction to differentiate BP and MDD.

METHODS

Twenty-three age and gender matched BP, 20 MDD and 23 healthy controls (HC) were part of a discovery cohort to identify neurophysiological differences between groups and build a classification model of these disorders. The replication of this model was then tested in an independent second cohort of 17 BP, 19 MDD and 19 HC. All participants were symptom-remitted for at least two weeks. We compared neural responses to target stimuli during an auditory oddball task, computing peak amplitude and latency of the P300 component extracted from the midline centro-parietal electrode.

RESULTS

BP had significantly smaller P300 amplitudes compared to both MDD and HC, whereas there were no differences between MDD and HC. The differences between groups were replicated in the second cohort, however the accuracy level of the classification model was only 53.5%.

LIMITATIONS

Small sample sizes may have led to low accuracy levels of the classification model.

CONCLUSION

Specific neural mechanisms of attention and context updating seem not to recover with symptom remission in BP. These findings contribute to the detection of a potential electrophysiological marker for BP, which may allow its differentiation from unipolar major depressive disorder.

Rate of diagnostic conversion to bipolar disorder in adults with unipolar depression and psychopharmacological treatment in the republic of Korea: A nationwide register-based study

BACKGROUND

Patients with bipolar disorder (BD) and depressive episodes are usually diagnosed with major depressive disorder (MDD). It is clinically important to estimate diagnostic conversion rate from MDD to BD and identify factors characterizing MDD patients at highest risk. We investigated conversion rate from depression to BD, stratified by age and sex, and associated psychopharmacological treatment patterns.

METHODS

Data were extracted from the National Health Insurance to include 817,759 patients 18 years or older with new-onset antidepressant-treated depression between 2011 and 2015. We estimated rate of conversion from unipolar depression to BD stratified by age and sex during follow-up (357,343 person-years) and investigated the related medication patterns.

RESULTS

During follow-up (median, 155 days; range, 2-1,442 days), 19,179 patients had diagnostic conversion to BD. Conversion rate was highest for patients aged 18-29 years; it gradually decreased with age until 60-69 years. Overall conversion rate to BD was 58.48 per 1,000 person-years for males and 50.97 per 1,000 person-years for females. For patients aged 18-39 years, the rate was higher for females. Patients with conversion to BD were prescribed more antidepressants. When the diagnosis changed to BD, 51% of patients were prescribed additional antipsychotics and/or mood stabilizers.

LIMITATIONS

The limited follow-up period may have underestimated conversion rate to BD. Data were restricted to participants with pharmaceutically treated depression.

CONCLUSIONS

The rate of diagnostic conversion from depression to BD differed by sex and age and was highest for females aged 18-29 years. Diagnostic conversion was accompanied by relevant prescription changes.

Diagnostic Stability in Bipolar Disorder: A Narrative Review

LEARNING OBJECTIVES

After participating in this activity, learners should be better able to:• Evaluate diagnostic stability in bipolar disorder• Analyze the factors contributing to diagnostic stability OBJECTIVE: Diagnostic stability is the degree to which a diagnosis remains unchanged during follow-up. It is an important measure of predictive validity in bipolar disorder (BD). In this study, we review the literature concerning diagnostic stability in BD, analyze the factors contributing to diagnostic stability, and describe the implications of diagnostic boundaries and diagnostic delay.

METHODS

A comprehensive literature search of MEDLINE and EMBASE databases was conducted, including all studies published from 1980 to 2016, to evaluate the diagnostic stability of BD. Thirty-seven articles were included: 6 focusing mainly on BD, 18 on psychotic disorders, 10 on depression, and 3 on diagnostic stability in psychiatric disorders in general. Data analysis was performed in standardized fashion using a predefined form.

RESULTS

Despite a high variability of the methodological approaches taken, an acceptable degree of diagnostic stability was found. The most common criteria for evaluating diagnostic stability were prospective consistency and retrospective consistency. The mean prospective and retrospective consistencies were 77.4% and 67.6%, respectively. A large majority of studies were performed in Europe or in North America (67.5%), compared to 21.6% in Asia and only 10.8% in Africa, Oceania, and South America. Extreme ages, female gender, psychotic symptoms, changes to treatment, substance abuse, and family history of affective disorder have been related to diagnostic instability.

CONCLUSIONS

Several factors appear to have a negative impact on the diagnostic stability, but the evidence is insufficient to draw any robust conclusions. Nevertheless, despite variable prospective and retrospective consistencies, the overall diagnostic stability is good. Standardized methods need to be used to obtain more accurate assessments of stability.

Aberrant brain network topology in fronto-limbic circuitry differentiates euthymic bipolar disorder from recurrent major depressive disorder

INTRODUCTION

Previous studies have established graph theoretical analysis of functional network connectivity (FNC) as a potential tool to detect neurobiological underpinnings of psychiatric disorders. Despite the promising outcomes in studies that examined FNC aberrancies in bipolar disorder (BD) and major depressive disorder (MDD), there is still a lack of research comparing both mood disorders, especially in a nondepressed state. In this study, we used graph theoretical network analysis to compare brain network properties of euthymic BD, euthymic MDD and healthy controls (HC) to evaluate whether these groups showed distinct features in FNC.

METHODS

We collected resting-state functional magnetic resonance imaging (fMRI) data from 20 BD patients, 15 patients with recurrent MDD as well as 30 age- and gender-matched HC. Graph theoretical analyses were then applied to investigate functional brain networks on a global and regional network level.

RESULTS

Global network analysis revealed a significantly higher mean global clustering coefficient in BD compared to HC. We further detected frontal, temporal and subcortical nodes in emotion regulation areas such as the limbic system and associated regions exhibiting significant differences in network integration and segregation in BD compared to MDD patients and HC. Participants with MDD and HC only differed in frontal and insular network centrality.

CONCLUSION

In conclusion, our findings indicate that a significantly altered brain network topology in the limbic system might be a trait marker specific to BD. Brain network analysis in these regions may therefore be used to differentiate euthymic BD not only from HC but also from patients with MDD.

Sub-threshold bipolar disorder in medication-free young subjects with major depression: Clinical characteristics and antidepressant treatment response

BACKGROUND

This study, for the first time, compared illness and antidepressant response characteristics of young subjects with major depression (MDD) at low (LRMDD) or high-risk (HRMDD) for developing bipolar disorder with characteristics of young bipolar (BPD) subjects and healthy controls (HC).

METHODS

One hundred and six young (15-30 yr), medication-free subjects MDD subjects (HRMDD, N = 51; LRMDD, N = 55) were compared with 32 BPD (Type I: 14; Type II: 18) as well as 49 HC subjects. Baseline illness characteristics and frequency of comorbid conditions were examined using Analysis of Variance and Cochran-Armitage trend test. Additionally, in MDD subjects, the effect of open-label antidepressant treatment for up to 24 months with periodic assessments was compared between HRMDD and LRMDD groups for treatment response, remission and (hypo)mania switch while controlling for attrition.

RESULTS

Significant gradation from LRMDD to HRMDD to BPD groups was found for increasing occurrence of alcohol dependence (p = 0.006), comorbid PTSD (p = 0.006), borderline personality traits (p = 0.001), and occurrence of melancholic features (p < 0.005). Antidepressant treatment response was similar between the two groups except that for the 12-month period HRMDD showed a trend for a lower response. Switch to (hypo)mania was infrequent in both groups though the HRMDD showed a higher occurrence of spikes in (hypo)mania symptoms (>25% increase in YMRS scores)(p = 0.04).

CONCLUSION

Findings of the study indicate that a substantial proportion of young MDD subjects share BPD illness characteristics. These HRMDD subjects, if treated with antidepressants, need to be monitored for development of BPD.

TRIAL REGISTRATION

NCT01811147.

Differentiation of Transformed Bipolar Disorder From Unipolar Depression by Resting-State Functional Connectivity Within Reward Circuit

Previous studies have found that neural functional abnormalities detected by functional magnetic resonance imaging (fMRI) in brain regions implicated in reward processing during reward tasks show promise to distinguish bipolar from unipolar depression (UD), but little is known regarding resting-state functional connectivity (rsFC) within the reward circuit. In this study, we investigated neurobiomarkers for early recognition of bipolar disorder (BD) by retrospectively comparing rsFC within the reward circuit between UD and depressed BD. Sixty-six depressed patients were enrolled, none of whom had ever experienced any manic/hypomanic episodes before baseline. Simultaneously, 40 matched healthy controls (HC) were also recruited. Neuroimaging data of each participant were obtained from resting-state fMRI scans. Some patients began to manifest bipolar disorder (tBD) during the follow-up period. All patients were retrospectively divided into two groups (33 tBD and 33 UD) according to the presence or absence of mania/hypomania in the follow-up. rsFC between key regions of the reward circuit was calculated and compared among groups. Results showed decreased rsFC between the left ventral tegmental area (VTA) and left ventral striatum (VS) in the tBD group compared with the UD group, which showed good accuracy in predicting diagnosis (tBD vs. UD) according to receiver operating characteristic (ROC) analysis. No significant different rsFC was found within the reward circuit between any patient group and HC. Our preliminary findings indicated that bipolar disorder, in early depressive stages before onset of mania/hypomania attacks, already differs from UD in the reward circuit of VTA-VS functional synchronicity at the resting state.

Decreased Functional Connectivity in Insular Subregions in Depressive Episodes of Bipolar Disorder and Major Depressive Disorder

Objective: Clinically, it is very difficult to distinguish between major depressive disorder (MDD) and bipolar disorder (BD) in the period of depression. Increasing evidence shows that the insula plays an important role in depression. We aimed to compare the resting-state functional connectivity (rsFC) of insular subregions in patients with MDD and BD in depressive episodes (BDD), who had never experienced manic or hypomanic episodes when they were scanned to identify biomarkers for the identification of two diseases. Methods: We recruited 21 BDD patients, 40 MDD patients and 70 healthy controls (HC). Resting-state functional magnetic resonance imaging (rs-fMRI) was performed. BDD patients had never had manic or hypomanic episodes when they were scanned, and the diagnoses were determined by follow-up. We divided the insula into three parts including the ventral anterior insular cortex (v-AIN), dorsal anterior insular cortex (d-AIN), and posterior insula (PI). The insular-based rsFC was compared among the three groups, and an analysis of the correlation between the rsFC value and Hamilton depression and anxiety scales was carried out. Results: BDD and MDD patients demonstrated decreased rsFC from the v-AIN to the left superior/middle frontal gyrus compared with the HC group. Versus MDD and HC groups, BDD patients exhibited decreased rsFC from the v-AIN to the area in the left orbital frontal gyrus and left superior temporal gyrus (included temporal pole), from the PI to the right lateral postcentral gyrus and from all three insular subregions to the somatosensory and motor cortex. Meanwhile, a correlation between the rsFC value of the PI-right lateral postcentral gyrus and anxiety score was observed in patients. Conclusion: Our findings show BDD and MDD patients have similar decreases in insular connectivity in the dorsal lateral frontal regions, and BDD patients have specific decreased insular connectivity, especially in the somatosensory and motor cortex, which may be used as imaging evidence for clinical identification.

Is suicide risk a predictor of diagnosis conversion to bipolar disorder?

To assess predictors of the diagnosis of bipolar disorder is important since it is known that the early diagnosis is associated with a better response to the treatment. Thus, the aim of this systematic review is to assess the role of the suicide risk in the diagnosis conversion to bipolar disorder. We searched Pubmed, Bireme, Scopus, and PsycINFO with no year restriction for articles containing the words (suicidal or suicide or suicide risk or suicide attempt) and (conversion or switch) and (bipolar disorder or mania or hypomania or bipolar disorders). The review included four studies, with only one confirming that subjects who converted to bipolar disorder had higher rates of suicide risk than subjects who did not convert to bipolar disorder. The main limitation of this review is that few longitudinal studies assessed the predictors of conversion to bipolar disorders. In conclusion, suicide risk appears to be a predictor of bipolar disorder; nevertheless, more studies are needed to confirm this association.

Amygdala Activation and Connectivity to Emotional Processing Distinguishes Asymptomatic Patients With Bipolar Disorders and Unipolar Depression

BACKGROUND

Mechanistically based neural markers, such as amygdala reactivity, offer one approach to addressing the challenges of differentiating bipolar and unipolar depressive disorders independently from mood state and acute symptoms. Although emotion-elicited amygdala reactivity has been found to distinguish patients with bipolar depression from patients with unipolar depression, it remains unknown whether this distinction is traitlike and present in the absence of an acutely depressed mood. We addressed this gap by investigating patients with bipolar disorder (BP) and unipolar major depressive disorder (MDD) in remission.

METHODS

Supraliminal and subliminal processing of faces exhibiting threat, sad, happy, and neutral emotions during functional magnetic resonance imaging was completed by 73 participants (23 BP patients and 25 MDD patients matched for age and gender, number of depressive episodes and severity; 25 age- and gender-matched healthy control subjects). We compared groups for activation and connectivity for the amygdala.

RESULTS

BP patients had lower left amygdala activation than MDD patients during supraliminal and subliminal threat, sad, and neutral emotion processing and for subliminal happy faces. BP patients also exhibited lower amygdala connectivity to the insula and hippocampus for threat and to medial orbitofrontal cortex for happy supraliminal and subliminal processing. BP patients also demonstrated greater amygdala-insula connectivity for sad supraliminal and subliminal face processing. Both patient groups were distinct from control subjects across several measures for activation and connectivity.

CONCLUSIONS

Independent of valence or level of emotional awareness, amygdala activation and connectivity during facial emotion processing can distinguish BP patients and MDD patients. These findings provide evidence that this neural substrate could be a potential trait marker to differentiate these two disorders largely independent of illness state.

Clinical predictors of conversion to bipolar disorder in a prospective longitudinal familial high-risk sample: focus on depressive features

BACKGROUND

Identifying clinical features that predict conversion to bipolar disorder (BD) in those at high familial risk (HR) would assist in identifying a more focused population for early intervention.

METHOD

In total 287 participants aged 12-30 (163 HR with a first-degree relative with BD and 124 controls (CONs)) were followed annually for a median of 5 years. We used the baseline presence of DSM-IV depressive, anxiety, behavioural and substance use disorders, as well as a constellation of specific depressive symptoms (as identified by the Probabilistic Approach to Bipolar Depression) to predict the subsequent development of hypo/manic episodes.

RESULTS

At baseline, HR participants were significantly more likely to report ⩾4 Probabilistic features (40.4%) when depressed than CONs (6.7%; p < .05). Nineteen HR subjects later developed either threshold (n = 8; 4.9%) or subthreshold (n = 11; 6.7%) hypo/mania. The presence of ⩾4 Probabilistic features was associated with a seven-fold increase in the risk of 'conversion' to threshold BD (hazard ratio = 6.9, p < .05) above and beyond the fourteen-fold increase in risk related to major depressive episodes (MDEs) per se (hazard ratio = 13.9, p < .05). Individual depressive features predicting conversion were psychomotor retardation and ⩾5 MDEs. Behavioural disorders only predicted conversion to subthreshold BD (hazard ratio = 5.23, p < .01), while anxiety and substance disorders did not predict either threshold or subthreshold hypo/mania.

CONCLUSIONS

This study suggests that specific depressive characteristics substantially increase the risk of young people at familial risk of BD going on to develop future hypo/manic episodes and may identify a more targeted HR population for the development of early intervention programs.

Case series of diagnostic shift from bipolar disorder to schizoaffective disorder

OBJECTIVE

To describe three cases of diagnostic shift from bipolar I disorder (BD) to schizoaffective disorder (SAD).

METHODS

BD patients were clinically assessed and followed up in a mood disorder program. A questionnaire was applied to assess clinical and socio-demographic characteristics, and a Structured Clinical Interview (SCID-I) was conducted.

RESULTS

We identified three patients with diagnosis conversion to SAD from 2005 to 2016. The mean time between BD diagnosis and the diagnostic shift to SAD was 9 years.

CONCLUSIONS

Psychotic symptoms may become persistent, chronic and unrelated to the presence of mood episodes many years after the beginning of BD. Psychiatrists should be aware of this and reassess the diagnosis during the longitudinal course of BD, especially in those patients who present psychotic symptoms.

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.

Prefrontal activation during a working memory task differs between patients with unipolar and bipolar depression: A preliminary exploratory study

BACKGROUND

To identify bipolar disorder during the initial stages of a depressive episode has always been a great clinical challenge. Patterns of functional brain activity may underlie the differences in the neural mechanisms of bipolar depression (BD) and unipolar depression (UD). This study aimed to investigate the differences in neural activity between BD and UD patients during executive task.

METHODS

We performed a 52-channel near-infrared spectroscopy (NIRS) scan in 39 patients with BD, 35 patients with UD, and 36 healthy controls (HCs). The relative concentration changes in oxygenated hemoglobin ([oxy-Hb]) and deoxygenated hemoglobin ([deoxy-Hb]) during a 1-back working memory task were measured for each channel. Clinical characteristics including current mood were evaluated within one week prior to NIRS examination.

RESULTS

Compared to HCs, BD (CH34: Z = -2.354, P = 0.019) and UD patients (CH18: Z = -2.358, P = 0.018; CH30: Z = -2.174, P = 0.030; CH34: Z = -1.990, P = 0.047) showed reduced activation of [oxy-Hb] in the inferior prefrontal region. Compared to patients with UD, patients with BD showed less decreased [oxy-Hb] changes in the left frontopolar cortex (FPC) (CH18: Z = -2.366, P = 0.018), left pars opercularis and pars triangularis (POPE/PTRI) regions (Broca's area) (CH30: Z = -2.333, P = 0.020). No correlation existed between clinical characteristics and NIRS measurements.

LIMITATIONS

The effect of medication could not be excluded, and behavioral data was not systematically collected.

CONCLUSION

The results from this preliminary exploratory study suggest distinct prefrontal activation patterns underlie BD and UD, especially in the left frontopolar region and Broca's area. The NIRS-based prefrontal activation measurement may serve as a potential marker to aid in differentiating bipolar from unipolar depression.

Is a delay in the diagnosis of bipolar disorder inevitable?

OBJECTIVE

A diagnosis of bipolar disorder (BD) is often preceded by an initial diagnosis of depression, creating a delay in the accurate diagnosis and treatment of BD. Although previous research has focused on predictors of a diagnosis change from depression to BD, the research on this delay in diagnosis is sparse. Therefore, the present study examined the time taken to make a BD diagnosis following an initial diagnosis of major depressive disorder in order to further understand the patient characteristics and psychological factors that may explain this delay.

METHOD

A total of 382 patients underwent a clinical evaluation by a psychiatrist and completed a series of questionnaires.

RESULTS

Ninety patients were initially diagnosed with depression with a later diagnosis of BD, with a mean delay in diagnostic conversion of 8.74 years. These patients who were later diagnosed with BD were, on average, diagnosed with depression at a younger age, experienced more manic symptoms, and had a more open personality style and better coping skills. Cox regressions showed that depressed patients with diagnoses that eventually converted to BD had been diagnosed with depression earlier and that this was related to a longer delay to conversion and greater likelihood of dysfunctional attitudes.

CONCLUSION

The findings from the present study suggested that an earlier diagnosis of depression is related to experiencing a longer delay in conversion to BD. The clinical implications of this are briefly discussed, with a view to reducing the seemingly inevitable delay in the diagnosis of BD.

Rate and predictors of conversion from unipolar to bipolar disorder: A systematic review and meta-analysis

OBJECTIVES

For the first time to present a systematic review and meta-analysis of the conversion rate and predictors of conversion from unipolar disorder to bipolar disorder.

METHODS

A systematic literature search up to October 2016 was performed. For the meta-analysis, we only included studies that used survival analysis to estimate the conversion rate.

RESULTS

A total of 31 studies were identified, among which 11 used survival analyses, including two register-based studies. The yearly rate of conversion to bipolar disorder decreased with time from 3.9% in the first year after study entry with a diagnosis of unipolar disorder to 3.1% in years 1-2, 1.0% in years 2-5 and 0.8% in years 5-10. A total of eight risk factors were evaluated comprising gender, age at onset of unipolar disorder, number of depressive episodes, treatment resistance to antidepressants, family history of bipolar disorder, the prevalence of psychotic depression, the prevalence of chronic depression, and severity of depression. It was not possible to identify risk factors that were consistently or mainly confirmed to predict conversion across studies.

CONCLUSIONS

The conversion rate from unipolar to bipolar disorder decreases with time. It was not possible to identify predictors of conversion that were consistently or mainly confirmed across studies, which may be due to variations in methodology across studies.

Postpartum depression: bipolar or unipolar? Analysis of 434 Polish postpartum women

Objective

To assess the prevalence of soft bipolar features in a sample of women with postpartum depressive symptoms, as well as to compare the sociodemographic and obstetric characteristics of subjects with bipolar or unipolar postpartum depressive symptomatology.

Methods

Four hundred and thirty-four participants were enrolled in this cross-sectional study. Postpartum depression (PPD) symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS), while the Mood Disorder Questionnaire (MDQ) was used to screen for bipolarity features.

Results

Of the 434 participants, 66 (15.2%) scored ≥ 13 points on the EPDS, thus fulfilling the screening criteria, and 103 scored ≥ 7 points on the MDQ. In comparison with non-depressed subjects, the women who scored positively on the EPDS were significantly more likely to exhibit symptoms of bipolar spectrum disorders (38 vs. 21%; chi-square test, p = 0.015). Women with bipolar PPD symptomatology were significantly younger than those exhibiting unipolar PPD symptoms (31.0±4.8 years vs. 28.5±4.1 years; t-test, p = 0.03). The groups did not differ in terms of obstetric characteristics.

Conclusion

Our findings suggest that patients with PPD symptomatology may be more likely to exhibit soft bipolarity features as compared with non-depressed women.

Mixed-up about how to diagnose and treat mixed features in major depressive episodes

The classical point of view-that major depressive episodes (MDEs), no matter what additional symptoms are present, should be treated first line with antidepressants-is now giving way to new a notion. The idea is that MDEs mixed with a few symptoms of mania/hypomania should be viewed very differently in terms of their natural history, clinical outcome, and treatment, and perhaps certain antipsychotics should be given as first-line treatment rather than antidepressant monotherapy.

Guidelines for the recognition and management of mixed depression

A significant minority of people presenting with a major depressive episode (MDE) experience co-occurring subsyndromal hypo/manic symptoms. As this presentation may have important prognostic and treatment implications, the DSM-5 codified a new nosological entity, the "mixed features specifier," referring to individuals meeting threshold criteria for an MDE and subthreshold symptoms of (hypo)mania or to individuals with syndromal mania and subthreshold depressive symptoms. The mixed features specifier adds to a growing list of monikers that have been put forward to describe phenotypes characterized by the admixture of depressive and hypomanic symptoms (e.g., mixed depression, depression with mixed features, or depressive mixed states [DMX]). Current treatment guidelines, regulatory approvals, as well the current evidentiary base provide insufficient decision support to practitioners who provide care to individuals presenting with an MDE with mixed features. In addition, all existing psychotropic agents evaluated in mixed patients have largely been confined to patient populations meeting the DSM-IV definition of "mixed states" wherein the co-occurrence of threshold-level mania and threshold-level MDE was required. Toward the aim of assisting clinicians providing care to adults with MDE and mixed features, we have assembled a panel of experts on mood disorders to develop these guidelines on the recognition and treatment of mixed depression, based on the few studies that have focused specifically on DMX as well as decades of cumulated clinical experience.

C-reactive protein: A differential biomarker for major depressive disorder and bipolar II disorder

Objectives We aimed to examine whether the C-reactive protein (CRP) level could be used to differentiate between major depressive disorder (MDD) and bipolar II disorder (BD II). Methods Ninety-six healthy controls, 88 BD II and 72 MDD drug-naïve patients in their major depressive episodes were enrolled. The fasting plasma level of high-sensitivity CRP was assessed at baseline and after treatment. Results The BD II patients presented significantly higher 17-item Hamilton Depression Rating Scale (HDRS) scores and CRP levels at baseline when adjustment for age, gender, and body mass index (P <  0.001 and P <  0.001, respectively). After treatment the CRP levels remained significantly different (P <  0.001), although the HDRS score was not significantly different between the BD II and MDD patients. A receiver-operating characteristic analysis showed that a baseline CRP level of 621.6 ng/mL could discriminate between BD II and MDD, with an area under the curve of 0.816 and a sensitivity and specificity of 0.699 and 0.882, respectively. Furthermore, the baseline CRP level greater than 621.6 ng/ml had 28.2 higher odds of a diagnosis of BD II (P <  0.001, 95% confidence interval: 10.96-72.35). Conclusions The level of CRP plays a role of biomarker to differentiate between MDD and BD II depression in both their depressed and euthymic state.

Distinguishing bipolar II depression from unipolar major depressive disorder: Differences in heart rate variability

OBJECTIVES

Bipolar II (BPII) depression is commonly misdiagnosed as unipolar depression (UD); however, an objective and reliable tool to differentiate between these disorders is lacking. Whether cardiac autonomic function can be used as a biomarker to distinguish BPII from UD is unknown.

METHODS

We recruited 116 and 591 physically healthy patients with BPII depression and UD, respectively, and 421 healthy volunteers aged 20-65 years. Interviewer and self-reported measures of depression/anxiety severity were obtained. Cardiac autonomic function was evaluated by heart rate variability (HRV) and frequency-domain indices of HRV.

RESULTS

Patients with BPII depression exhibited significantly lower mean R-R intervals, variance (total HRV), low frequency (LF)-HRV, and high frequency (HF)-HRV but higher LF/HF ratio compared to those with UD. The significant differences remained after adjusting for age. Compared to the controls, the patients with BPII depression showed cardiac sympathetic excitation with reciprocal vagal impairment, whereas the UD patients showed only vagal impairment. Depression severity independently contributed to decreased HRV and vagal tone in both the patients with BPII depression and UD, but increased sympathetic tone only in those with BPII depression.

CONCLUSIONS

HRV may aid in the differential diagnosis of BPII depression and UD as an adjunct to diagnostic interviews.

Resting-state functional network connectivity in prefrontal regions differs between unmedicated patients with bipolar and major depressive disorders

BACKGROUND

Differentiating bipolar disorder (BD) from major depressive disorder (MDD) often poses a major clinical challenge, and optimal clinical care can be hindered by misdiagnoses. This study investigated the differences between BD and MDD in resting-state functional network connectivity (FNC) using a data-driven image analysis method.

METHODS

In this study, fMRI data were collected from unmedicated subjects including 13 BD, 40 MDD and 33 healthy controls (HC). The FNC was calculated between functional brain networks derived from fMRI using group independent component analysis (ICA). Group comparisons were performed on connectivity strengths and other graph measures of FNC matrices.

RESULTS

Statistical tests showed that, compared to MDD, the FNC in BD was characterized by more closely connected and more efficient topological structures as assessed by graph theory. The differences were found at both the whole-brain-level and the functional-network-level in prefrontal networks located in the dorsolateral/ventrolateral prefrontal cortex (DLPFC, VLPFC) and anterior cingulate cortex (ACC). Furthermore, interconnected structures in these networks in both patient groups were negatively associated with symptom severity on depression rating scales.

LIMITATIONS

As patients were unmedicated, the sample sizes were relatively small, although they were comparable to those in previous fMRI studies comparing BD and MDD.

CONCLUSIONS

Our results suggest that the differences in FNC of the PFC reflect distinct pathophysiological mechanisms in BD and MDD. Such findings ultimately may elucidate the neural pathways in which distinct functional changes can give rise to the clinical differences observed between these syndromes.

Treatment response in relation to subthreshold bipolarity in patients with major depressive disorder receiving antidepressant monotherapy: a post hoc data analysis (KOMDD study)

BACKGROUND

The aim of this observational study was to determine whether subthreshold bipolarity affects treatment response and remission in patients with major depressive disorder receiving antidepressant (AD) monotherapy over a 6-month follow-up period.

METHODS

Seventy-eight patients with major depressive disorder were stratified into two subgroups according to the presence of subthreshold bipolarity, identified using the Korean version of the Mood Disorder Questionnaire (K-MDQ), which classifies patients as positive for a screening of bipolarity based on the cutoff for the total K-MDQ score (ie, 7 points). They received AD monotherapy such as escitalopram, sertraline, paroxetine, or tianeptine for 6 months. The Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale, and Beck Scale for Suicide Ideation were applied at baseline, 1 week, 3 weeks, 2 months, 3 months, and 6 months.

RESULTS

The mean HAMD, BDI, and Beck Scale for Suicide Ideation scores were higher in the bipolarity group than in the nonbipolarity group at 3 weeks. The mean BDI score was also higher in the bipolarity group than in the nonbipolarity group at 6 months. Evaluation of the ratio of improvement for each scale revealed different patterns of percentage changes between the two groups over the 6-month follow-up period. Furthermore, the response and remission rates (as assessed using BDI and HAMD scores) were higher in the nonbipolarity group than in the bipolarity group, with the exception of HAMD scores at the 3-week follow-up time point.

CONCLUSION

The findings of this study showed that depressed patients with bipolarity had a worse response to AD monotherapy than did those without bipolarity.

Mood disorders: neurocognitive models

OBJECTIVES

In recent years, a number of neurocognitive models stemming from psychiatry and psychology schools of thought have conceptualized the pathophysiology of mood disorders in terms of dysfunctional neural mechanisms that underpin and drive neurocognitive processes. Though these models have been useful for advancing our theoretical understanding and facilitating important lines of research, translation of these models and their application within the clinical arena have been limited-partly because of lack of integration and synthesis. Cognitive neuroscience provides a novel perspective for understanding and modeling mood disorders. This selective review of influential neurocognitive models develops an integrative approach that can serve as a template for future research and the development of a clinically meaningful framework for investigating, diagnosing, and treating mood disorders.

METHODS

A selective literature search was conducted using PubMed and PsychINFO to identify prominent neurobiological and neurocognitive models of mood disorders.

RESULTS

Most models identify similar neural networks and brain regions and neuropsychological processes in the neurocognition of mood, however, they differ in terms of specific functions attached to neural processes and how these interact. Furthermore, cognitive biases, reward processing and motivation, rumination, and mood stability, which play significant roles in the manner in which attention, appraisal, and response processes are deployed in mood disorders, are not sufficiently integrated. The inclusion of interactions between these additional components enhances our understanding of the etiology and pathophysiology of mood disorders.

CONCLUSIONS

Through integration of key cognitive functions and understanding of how these interface with neural functioning within neurocognitive models of mood disorders, a framework for research can be created for translation to diagnosis and treatment of mood disorders.

Discriminating Bipolar Disorder From Major Depression Based on SVM-FoBa: Efficient Feature Selection With Multimodal Brain Imaging Data

Discriminating between bipolar disorder (BD) and major depressive disorder (MDD) is a major clinical challenge due to the absence of known biomarkers; hence a better understanding of their pathophysiology and brain alterations is urgently needed. Given the complexity, feature selection is especially important in neuroimaging applications, however, feature dimension and model understanding present serious challenges. In this study, a novel feature selection approach based on linear support vector machine with a forward-backward search strategy (SVM-FoBa) was developed and applied to structural and resting-state functional magnetic resonance imaging data collected from 21 BD, 25 MDD and 23 healthy controls. Discriminative features were drawn from both data modalities, with which the classification of BD and MDD achieved an accuracy of 92.1% (1,000 bootstrap resamples). Weight analysis of the selected features further revealed that the inferior frontal gyrus may characterize a central role in BD-MDD differentiation, in addition to the default mode network and the cerebellum. A modality-wise comparison also suggested that functional information outweighs anatomical by a large margin when classifying the two clinical disorders. This work validated the advantages of multimodal joint analysis and the effectiveness of SVM-FoBa, which has potential for use in identifying possible biomarkers for several mental disorders.

Conversion from depression to bipolar disorder in a cohort of young people in England, 1999-2011: A national record linkage study

OBJECTIVE

To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorder (BP) (ICD10 codes F31) in an English national cohort. It was hypothesised that early-onset BP (age <18 years) is a more severe form of the disorder, with a more rapid, and higher rate of conversion from depression to BP.

METHOD

This record linkage study used English national Hospital Episode Statistics (HES) covering all NHS inpatient and day case admissions between 1999 and 2011.

RESULTS

The overall rate of conversion from depression to BP for all ages was 5.65% (95% CI: 5.48-5.83) over a minimum 4-year follow-up period. The conversion rate from depression to BP increased in a linear manner with age from 10-14 years - 2.21% (95% C: 1.16-4.22) to 30-34 years - 7.06% (95% CI: 6.44-7.55) (F1,23=77.6, p=0.001, R(2)=0.77). The time to conversion was constant across the age range. The rate of conversion was higher in females (6.77%; 95% CI: 6.53-7.02) compared to males, (4.17%; 95% CI: 3.95-4.40) (χ(2)=194, p<0.0001), and in those with psychotic depression 8.12% (95% CI: 7.65-8.62) compared to non-psychotic depression 5.65% (95% CI: 5.48-5.83) (χ(2)=97.0, p<0.0001).

LIMITATIONS

The study was limited to hospital discharges and diagnoses were not standardised.

CONCLUSIONS

Increasing conversion rate from depression to bipolar disorder with age, and constant time for conversion across the age range does not support the notion that early-onset BP is a more severe form of the disorder.

Bipolar disorders following initial depression: modeling predictive clinical factors

OBJECTIVE

Most first lifetime episodes among persons eventually diagnosed with bipolar disorder are depressive, often with years of delay to a final differentiation from unipolar major depression. To support early differentiation, we tested several predictive factors for association with later diagnoses of bipolar disorder.

METHOD

With data from mood-disorder patients with first-lifetime episodes of major depression, we used multivariate, logistic modeling and Bayesian methods including Receiver Operating Characteristic curves to evaluate ability of one or more selected factors to differentiate patients who later met DSM-IV-TR diagnostic criteria for bipolar disorder and not unipolar major depressive disorder.

RESULTS

We analyzed data from 2146 patients (642 bipolar, 1504 unipolar) at risk for 13 years following initial depressive episodes. In multivariate modeling for 812 subjects with information on all clinical factors considered, seven significantly and independently differentiated bipolar from unipolar disorders, ranking (by significance): (a) ≥4 previous depressive episodes, (b) suicidal acts, (c) cyclothymic temperament, (d) family history of bipolar disorder, (e) substance-abuse, (f) younger-at-onset, or onset-age <25, and (g) male sex; four of these (c, d, f, g) can be identified at illness-onset. Bayesian analysis indicated optimal sensitivity and specificity at 2-4 factors/person and correct classification of 64-67% of cases, and ROC analysis of factors/person yielded a significant area-under-the-curve of 0.72 [CI: 0.68-0.75].

CONCLUSIONS

In multivariate modeling, 7 factors were significantly and independently associated with bipolar disorder diagnosed up to 13 years after initial depression.

Can unipolar and bipolar pediatric major depression be differentiated from each other? A systematic review of cross-sectional studies examining differences in unipolar and bipolar depression

INTRODUCTION

While pediatric mania and depression can be distinguished from each other, differentiating between unipolar major depressive disorder (unipolar MDD) and bipolar major depression (bipolar MDD) poses unique clinical and therapeutic challenges. Our aim was to examine the current body of knowledge on whether unipolar MDD and bipolar MDD in youth could be distinguished from one another in terms of clinical features and correlates.

METHODS

A systematic literature search was conducted on studies assessing the clinical characteristics and correlates of unipolar MDD and bipolar MDD in youth.

RESULTS

Four scientific papers that met our priori inclusion and exclusion criteria were identified. These papers reported that bipolar MDD is distinct from unipolar MDD in its higher levels of depression severity, associated impairment, psychiatric co-morbidity with oppositional defiant disorder, conduct disorder and anxiety disorders, and family history of mood and disruptive behavior disorders in first-degree relatives.

LIMITATIONS

Though we examined a sizeable and diverse sample, we were only able to identify four cross sectional informative studies in our review. Therefore, our conclusions should be viewed as preliminary.

CONCLUSIONS

These findings can aid clinicians in differentiating the two forms of MDD in youth.

Risk of bipolar disorder and psychotic features in patients initially hospitalised with severe depression

OBJECTIVE

Severe depression may be a risk factor for diagnostic conversion into bipolar disorder (BD), and psychotic depression (PD) has been consistently associated with BD. The aims of the present study were to investigate the stability of the diagnosis of severe depression and the differences between PD and non-psychotic severe depression (non-PD), as well as to assess the effectiveness of electroconvulsive therapy (ECT).

METHODS

Patients who were hospitalised for severe depression (diagnosed according to ICD-10) both with and without psychotic symptoms (n=89; mean age=55.6 years, SD=13.9) from 2001 to 2010 were retrospectively assessed.

RESULTS

By the 75th month of follow-up assessments, 11(12.4%) patients had developed BD. Among these 11 converters, nine had developed BD within 1 year after admission. Only sub-threshold hypomanic symptoms were significantly related to developing BD. The number of depressive episodes and history of physical diseases were significantly increased in non-PD compared with PD patients, whereas ECT was significantly increased in PD compared with non-PD patients. There was a significant association between length of stay at the hospital and the number of days between admission and ECT.

CONCLUSION

Sub-threshold hypomanic symptoms may represent a prodrome of BD or an indicator of an already manifest phenotype, especially in older patients, which suggests cautious use of antidepressants. In severe depression, non-PD may often occur secondary to physical diseases and patients may experience increased recurrences compared with PD patients, which may be a more 'primary' disorder and often requires ECT treatments. ECT is effective for severe depression regardless of the presence of any psychotic feature; the earlier ECT is introduced, the better the expected treatment outcome.

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.

A diagnosis of bipolar spectrum disorder predicts diagnostic conversion from unipolar depression to bipolar disorder: a 5-year retrospective study

BACKGROUND

The major aims of this study were to identify factors that may predict the diagnostic conversion from major depressive disorder (MDD) to bipolar disorder (BP) and to evaluate the predictive performance of the bipolar spectrum disorder (BPSD) diagnostic criteria.

METHODS

The medical records of 250 patients with a diagnosis of MDD for at least 5 years were retrospectively reviewed for this study.

RESULTS

The diagnostic conversion from MDD to BP was observed in 18.4% of 250 MDD patients, and the diagnostic criteria for BPSD predicted this conversion with high sensitivity (0.870) and specificity (0.917). A family history of BP, antidepressant-induced mania/hypomania, brief major depressive episodes, early age of onset, antidepressant wear-off, and antidepressant resistance were also independent predictors of this conversion.

LIMITATIONS

This study was conducted using a retrospective design and did not include structured diagnostic interviews.

CONCLUSIONS

The diagnostic criteria for BPSD were highly predictive of the conversion from MDD to BP, and conversion was associated with several clinical features of BPSD. Thus, the BPSD diagnostic criteria may be useful for the prediction of bipolar diathesis in MDD patients.

Features preceding diagnosis of bipolar versus major depressive disorders

BACKGROUND

Better and earlier predictive differentiation of bipolar (BD) vs. unipolar major depressive disorder (UD) diagnoses should improve long-term clinical planning.

METHODS

We reviewed randomly selected clinical records of 334 adults diagnosed with DSM-IV-TR BD-I (n=109), BD-II (n=106), and UD (n=119) and compared features preceding major affective episodes or diagnoses, using bivariate, multivariate, and Bayesian methods.

RESULTS

We identified antecedents selectively associated with later BD vs. UD in 52.6% vs. 31.1% of subjects in childhood, starting at age 7.4 years, and 60.0% vs. 32.8% in adolescence, with far more features in BD than UD cases (10.3 vs. 4.64/100 person-years; p<0.001). In multivariate modeling, BD-selective factors were: younger at first clinical event > male sex > family BD-history > cyclothymic or hyperthymic temperament > antecedents/person-year. Nonaffective (anxiety, eating, or substance-use) disorders preceded BD vs. UD in 41.4% vs. 28.6% of subjects (p=0.02). By ROC analysis, differential prediction of BD vs. UD was optimal with any ≥ 3 factors/person.

LIMITATIONS

The validity and timing of antecedent events and factors identified retrospectively from clinical records could not be verified independently, but information was recorded systematically and consistently by a single mood-disorder expert prior to diagnosis, and extracted by two independent observers.

COMMENT

Early clinical features distinguished later BD from UD, often by years. Such prediction should improve treatment-planning and limit risk of mood-switching.

Toward stratified treatments for bipolar disorders

In bipolar disorders, there are unclear diagnostic boundaries with unipolar depression and schizophrenia, inconsistency of treatment guidelines, relatively long trial-and-error phases of treatment optimization, and increasing use of complex combination therapies lacking empirical evidence. These suggest that the current definition of bipolar disorders based on clinical symptoms reflects a clinically and etiologically heterogeneous entity. Stratification of treatments for bipolar disorders based on biomarkers and improved clinical markers are greatly needed to increase the efficacy of currently available treatments and improve the chances of developing novel therapeutic approaches. This review provides a theoretical framework to identify biomarkers and summarizes the most promising markers for stratification regarding beneficial and adverse treatment effects. State and stage specifiers, neuropsychological tests, neuroimaging, and genetic and epigenetic biomarkers will be discussed with respect to their ability to predict the response to specific pharmacological and psychosocial psychotherapies for bipolar disorders. To date, the most reliable markers are derived from psychopathology and history-taking, while no biomarker has been found that reliably predicts individual treatment responses. This review underlines both the importance of clinical diagnostic skills and the need for biological research to identify markers that will allow the targeting of treatment specifically to sub-populations of bipolar patients who are more likely to benefit from a specific treatment and less likely to develop adverse reactions.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of unipolar depressive disorders. part 2: maintenance treatment of major depressive disorder-update 2015

These guidelines for the treatment of unipolar depressive disorders systematically review available evidence pertaining to the biological treatment of patients with major depression and produce a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians assessing and treating patients with these conditions. The relevant data have been extracted primarily from various treatment guidelines and panels for depressive disorders, as well as from meta-analyses/reviews on the efficacy of antidepressant medications and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and was then categorized into five levels of evidence (CE A-F) and five levels of recommendation grades (RG 1-5). This second part of the WFSBP guidelines on depressive disorders covers the management of the maintenance phase treatment, and is primarily concerned with the biological treatment (including pharmacological and hormonal medications, electroconvulsive therapy and other brain stimulation treatments) of adults and also, albeit to a lesser extent, children, adolescents and older adults.

Comparison of clinical characteristics of bipolar and depressive disorders in Korean clinical sample of youth: a retrospective chart review

The purpose of this study was to compare the clinical characteristics of bipolar disorder I, II (BD I and II) and not otherwise specified (BD NOS) to those of major depressive disorder (MDD) in a clinical sample of Korean children and adolescents. This study was a cross-sectional review of longitudinal observational data. Two psychiatrists retrospectively reviewed the medical records of 198 children and adolescents (age 6-18) that were diagnosed as having bipolar or depressive disorders from March 2010 to February 2012 at Department of Psychiatry of Asan Medical Center, Seoul, Korea. Every subject's diagnoses were reviewed and confirmed. BD I, II and MDD were assessed according to the Diagnostic and Statistical Manual-IV criteria. BD NOS was defined based on the criteria for the Course and Outcome of Bipolar Youth study. Comparisons were made in demographic information, clinical characteristics, family history, and psychiatric comorbidities at baseline and during observation. Among 198 subjects, 20 (10.1 %) subjects were diagnosed as having BD I, 10 (5.1 %) as BD II, 25 (12.6 %) as BD NOS and 143 (73.7 %) as MDD. BD depression was associated with mood change while taking an antidepressant, familial bipolarity, aggressive behaviors, and atypical features. Comorbid obsessive-compulsive disorder tended to be higher in BD NOS than in MDD. Presence of psychosocial stressors was more common in MDD than in BD depression. In children and adolescents, bipolar depression is distinct from unipolar depression in family history, comorbidity, and clinical characteristics.

Amygdala excitability to subliminally presented emotional faces distinguishes unipolar and bipolar depression: an fMRI and pattern classification study

BACKGROUND

Bipolar disorder and Major depressive disorder are difficult to differentiate during depressive episodes, motivating research for differentiating neurobiological markers. Dysfunctional amygdala responsiveness during emotion processing has been implicated in both disorders, but the important rapid and automatic stages of emotion processing in the amygdala have so far never been investigated in bipolar patients.

METHODS

fMRI data of 22 bipolar depressed patients (BD), 22 matched unipolar depressed patients (MDD), and 22 healthy controls (HC) were obtained during processing of subliminal sad, happy and neutral faces. Amygdala responsiveness was investigated using standard univariate analyses as well as pattern-recognition techniques to differentiate the two clinical groups. Furthermore, medication effects on amygdala responsiveness were explored.

RESULTS

All subjects were unaware of the emotional faces. Univariate analysis revealed a significant group × emotion interaction within the left amygdala. Amygdala responsiveness to sad>neutral faces was increased in MDD relative to BD. In contrast, responsiveness to happy>neutral faces showed the opposite pattern, with higher amygdala activity in BD than in MDD. Most of the activation patterns in both clinical groups differed significantly from activation patterns of HC--and therefore represent abnormalities. Furthermore, pattern classification on amygdala activation to sad>happy faces yielded almost 80% accuracy differentiating MDD and BD patients. Medication had no significant effect on these findings.

CONCLUSIONS

Distinct amygdala excitability during automatic stages of the processing of emotional faces may reflect differential pathophysiological processes in BD versus MDD depression, potentially representing diagnosis-specific neural markers mostly unaffected by current psychotropic medication.

Amygdala excitability to subliminally presented emotional faces distinguishes unipolar and bipolar depression: an fMRI and pattern classification study

BACKGROUND

Bipolar disorder and Major depressive disorder are difficult to differentiate during depressive episodes, motivating research for differentiating neurobiological markers. Dysfunctional amygdala responsiveness during emotion processing has been implicated in both disorders, but the important rapid and automatic stages of emotion processing in the amygdala have so far never been investigated in bipolar patients.

METHODS

fMRI data of 22 bipolar depressed patients (BD), 22 matched unipolar depressed patients (MDD), and 22 healthy controls (HC) were obtained during processing of subliminal sad, happy and neutral faces. Amygdala responsiveness was investigated using standard univariate analyses as well as pattern-recognition techniques to differentiate the two clinical groups. Furthermore, medication effects on amygdala responsiveness were explored.

RESULTS

All subjects were unaware of the emotional faces. Univariate analysis revealed a significant group × emotion interaction within the left amygdala. Amygdala responsiveness to sad>neutral faces was increased in MDD relative to BD. In contrast, responsiveness to happy>neutral faces showed the opposite pattern, with higher amygdala activity in BD than in MDD. Most of the activation patterns in both clinical groups differed significantly from activation patterns of HC--and therefore represent abnormalities. Furthermore, pattern classification on amygdala activation to sad>happy faces yielded almost 80% accuracy differentiating MDD and BD patients. Medication had no significant effect on these findings.

CONCLUSIONS

Distinct amygdala excitability during automatic stages of the processing of emotional faces may reflect differential pathophysiological processes in BD versus MDD depression, potentially representing diagnosis-specific neural markers mostly unaffected by current psychotropic medication.