Clinical and Environmental Risk Factors for Bipolar Disorder: Review of Prospective Studies

Larger putamen in individuals at risk and with manifest bipolar disorder

BACKGROUND

Individuals at risk for bipolar disorder (BD) have a wide range of genetic and non-genetic risk factors, like a positive family history of BD or (sub)threshold affective symptoms. Yet, it is unclear whether these individuals at risk and those diagnosed with BD share similar gray matter brain alterations.

METHODS

In 410 male and female participants aged 17-35 years, we compared gray matter volume (3T MRI) between individuals at risk for BD (as assessed using the EPIbipolar scale; n = 208), patients with a DSM-IV-TR diagnosis of BD (n = 87), and healthy controls (n = 115) using voxel-based morphometry in SPM12/CAT12. We applied conjunction analyses to identify similarities in gray matter volume alterations in individuals at risk and BD patients, relative to healthy controls. We also performed exploratory whole-brain analyses to identify differences in gray matter volume among groups. ComBat was used to harmonize imaging data from seven sites.

RESULTS

Both individuals at risk and BD patients showed larger volumes in the right putamen than healthy controls. Furthermore, individuals at risk had smaller volumes in the right inferior occipital gyrus, and BD patients had larger volumes in the left precuneus, compared to healthy controls. These findings were independent of course of illness (number of lifetime manic and depressive episodes, number of hospitalizations), comorbid diagnoses (major depressive disorder, attention-deficit hyperactivity disorder, anxiety disorder, eating disorder), familial risk, current disease severity (global functioning, remission status), and current medication intake.

CONCLUSIONS

Our findings indicate that alterations in the right putamen might constitute a vulnerability marker for BD.

Is structural connectivity different in child and adolescent relatives of patients with bipolar disorder? A narrative review according to studies with DTI

INTRODUCTION

Bipolar disorder (BD) has been associated with a decrease in white matter integrity. Diffusion tensor imaging (DTI) studies have enabled these changes to be elucidated with higher quality. Due to BD's high heritability, some studies have been conducted in relatives of BD patients looking at white matter integrity, and have found that structural connectivity may also be affected. This alteration has been proposed as a potential BD biomarker of vulnerability. However, there are few studies in children and adolescents.

OBJECTIVE

To conduct a review of the literature on changes in white matter integrity determined by DTI in high-risk children and adolescents.

RESULTS

Brain structural connectivity in the paediatric population is described in studies using DTI. Changes in the myelination process from its evolution within normal neurodevelopment to the findings in fractional anisotropy (FA) in BD patients and their high-risk relatives are also described.

CONCLUSIONS

Studies show that both BD patients and their at-risk relatives present a decrease in FA in specific brain regions. Studies in children and adolescents with a high risk of BD, indicate a reduced FA in axonal tracts involved in emotional and cognitive functions. Decreased FA can be considered as a vulnerability biomarker for BD.

The Mood Disorder Assessment Schedule: Initial validation of a new measure for early identification of bipolar spectrum disorders in inpatient adolescents

Due to the significant impairment associated with subthreshold bipolar symptomatology and the harmful effects of delayed diagnosis, there is a great need for diagnostic tools that can facilitate early identification of bipolar spectrum disorders. The Mood Disorder Assessment Schedule (MDAS) is a newly developed measure that focuses on autonomous changes in mood and energy, a key indicator of bipolar spectrum problems which is not included in current diagnostic tools for bipolar disorders. The current study tested the ability of the MDAS to identify individuals at risk for bipolar spectrum disorders. In a cross-sectional sample of 396 inpatient adolescents, the MDAS identified a group of individuals with several bipolar spectrum disorder (BSD) indicators, including greater manic and depressive symptoms, affective lability, suicidal behavior, adverse reactions to antidepressants, and a family history of bipolar disorder and suicidal behavior. When compared to a standard diagnostic interview for bipolar disorders (i.e., Kiddie Schedule for Affective Disorders and Schizophrenia [KSADS]), the MDAS yielded stronger clinical utility in its ability to identify individuals with BSD indicators. Therefore, the MDAS appears to be a promising diagnostic tool for identifying adolescents at risk for BSDs and may help facilitate earlier diagnosis and prevent harmful effects of improper treatment.

Anxiety in bipolar disorder: A review of publication trends

BACKGROUND

Although anxiety is highly prevalent in people with bipolar disorders and has deleterious impact on the course of the illness, past reviews have shown that many aspects of the topic remain under-researched. This scoping review aims to provide a comprehensive overview of the literature addressing anxiety in bipolar disorder (A-BD) between 2011 and 2020, assess if the interest in the topic has increased over the period and map the publication trends.

METHODS

Three databases were systematically searched, and all articles were screened at the title/abstract and full text level based on inclusion and exclusion criteria. Of these, 1099 articles were included in the study. The annual number of articles on A-BD published between 2011 and 2020 was calculated and articles addressing it as a primary topic (n = 310) were classified into 4 categories and 11 subcategories to identify gaps in the knowledge.

RESULTS

The results show no clear increase in the number of annual publications during the period and much of the available literature is of a descriptive nature. Less is known about the processes underlying the comorbidity and about treatment approaches.

LIMITATIONS

Given the large scope of the research question, no quality assessment of the evidence was made. Only articles in English or French were considered.

CONCLUSIONS

These results highlight the need to change the focus of research efforts to better understand and address this unique set of conditions in clinical settings.

Clinical Value of Inflammatory and Neurotrophic Biomarkers in Bipolar Disorder: A Systematic Review and Meta-Analysis

Bipolar disorder (BD) is a multifactorial chronic psychiatric disease highly defined by genetic, clinical, environmental and social risk factors. The present systematic review and meta-analysis aimed to examine the relationship between inflammatory and neurotrophic factors and clinical, social and environmental factors involved in the development and the characterization of BD. Web of Science, PubMed, PsycINFO, Scopus and Science Direct were searched by two independent reviewers. The systematic review was registered in PROSPERO (CRD42020180626). A total of 51 studies with 4547 patients with a diagnosis of BD were selected for systematic review. Among them, 18 articles were included for meta-analysis. The study found some evidence of associations between BDNF and/or inflammatory factors and different stressors and functional and cognitive impairment, but limitations prevented firm conclusions. The main finding of the meta-analysis was a negative correlation between circulating levels of BDNF and depression severity score (standardized mean difference = −0.22, Confidence Interval 95% = −0.38, −0.05, p = 0.01). Evidence indicates that BDNF has a role in the depressive component of BD. However, the poor consistency found for other inflammatory mediators clearly indicates that highly controlled studies are needed to identity precise biomarkers of this disorder.

Bipolar disorders in severe anorexia nervosa: prevalence and relationships

BACKGROUND

The comorbidity between anorexia nervosa (AN) and bipolar disorders (BD) among subjects with AN is a matter of some debate, regarding its existence, its impact on the clinical manifestations of AN and the nature of the relationship between these disorders. Our aims were: (1) to evaluate the prevalence of BD among patients with severe AN; and (2) to determine whether people with a history of BD present particular clinical AN characteristics in comparison to people with a comorbid major depressive disorder or with any mood disorder comorbidity.

METHODS

177 AN subjects were surveyed to assess their nutritional state, dietary symptomatology, psychiatric comorbidities, treatments received and associated response. The diagnosis of BD relied on DSM-5 criteria, using the short-CIDI. The discriminant features of patients with AN and suspected BD were identified, comparing them to the characteristics of AN patients without any mood disorder and AN patients suffering from major depressive disorder.

RESULTS

Among AN subjects, 11.3% were suspected to have BD. In comparison with the two other groups, these patients had more severe clinical profiles in terms of duration of AN (6.7 years, p = 0.020), nutritional state (p max  =  0.031), levels of anxious, depressive and dietary symptoms, lifetime comorbidity with anxious disorders, quality-of-life (p =  0.001) and treatment (antidepressant and mood stabilizers, (p  =  0.029)).

LIMITATIONS

The participants were hospitalized in a tertiary center with severe AN. The diagnosis of BD requires evaluation using a more precise diagnostic instrument CONCLUSION: These results underline the importance of systematic early detection of BD and mood disorders among individuals with severe AN, to provide optimum treatment.

LEVEL OF EVIDENCE

III: Evidence obtained from a cross-sectional study.

Women and ethnoracial minorities with poor cardiovascular health measures associated with a higher risk of developing mood disorder

Background

Mood disorders (MDS) are a type of mental health illness that effects millions of people in the United States. Early prediction of MDS can give providers greater opportunity to treat these disorders. We hypothesized that longitudinal cardiovascular health (CVH) measurements would be informative for MDS prediction.

Methods

To test this hypothesis, the American Heart Association’s Guideline Advantage (TGA) dataset was used, which contained longitudinal EHR from 70 outpatient clinics. The statistical analysis and machine learning models were employed to identify the associations of the MDS and the longitudinal CVH metrics and other confounding factors.

Results

Patients diagnosed with MDS consistently had a higher proportion of poor CVH compared to patients without MDS, with the largest difference between groups for Body mass index (BMI) and Smoking. Race and gender were associated with status of CVH metrics. Approximate 46% female patients with MDS had a poor hemoglobin A1C compared to 44% of those without MDS; 62% of those with MDS had poor BMI compared to 47% of those without MDS; 59% of those with MDS had poor blood pressure (BP) compared to 43% of those without MDS; and 43% of those with MDS were current smokers compared to 17% of those without MDS.

Conclusions

Women and ethnoracial minorities with poor cardiovascular health measures were associated with a higher risk of development of MDS, which indicated the high utility for using routine medical records data collected in care to improve detection and treatment for MDS among patients with poor CVH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-021-01674-9.

Risk factors for new-onset bipolar disorder in a community cohort: A five-year follow up study

The aim of this study was to assess the risk factors for new-onset Bipolar Disorder (BD) in a community sample of young adults. This is a prospective cohort study including a population-based sample of young adults aged between 18-24 years. The baseline took place from 2007 to 2009, and 1560 subjects were included. Five years after, 1244 individuals were re-evaluated (79.7% retention). Substance abuse/dependence was assessed using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), and mental disorders were assessed using the Mini International Neuropsychiatric Interview 5.0 (MINI) at both waves. The cumulative incidence of BD in five years was 4.6%. There was no significant association between sociodemographic factors and BD incidence. Tobacco, cannabis, cocaine/crack, other substances abuse/dependence increased the relative risk for BD. Depressive, anxiety, post-traumatic stress disorders, and the suicide risk increased the relative risk to BD. Depressive episode was the strongest risk factor for BD, followed by other mental disorders and substance abuse/dependence in a probabilistic community sample of young adults. Preventive actions in mental health directed at the non-clinical population are needed for early detection and better management of BD.

Is Structural Connectivity Different in Child and Adolescent Relatives of Patients with Bipolar Disorder? A Narrative Review According to Studies with DTI

INTRODUCTION

Bipolar disorder (BD) has been associated with a decrease in white matter integrity. Diffusion tensor imaging (DTI) studies have enabled these changes to be elucidated with higher quality. Due to BD's high heritability, some studies have been conducted in relatives of BD patients looking at white matter integrity, and have found that structural connectivity may also be affected. This alteration has been proposed as a potential BD biomarker of vulnerability. However, there are few studies in children and adolescents.

OBJECTIVE

To conduct a review of the literature on changes in white matter integrity determined by DTI in high-risk children and adolescents.

RESULTS

Brain structural connectivity in the paediatric population is described in studies using DTI. Changes in the myelination process from its evolution within normal neurodevelopment to the findings in fractional anisotropy (FA) in BD patients and their high-risk relatives are also described.

CONCLUSIONS

Studies show that both BD patients and their at-risk relatives present a decrease in FA in specific brain regions. Studies in children and adolescents with a high risk of BD, indicate a reduced FA in axonal tracts involved in emotional and cognitive functions. Decreased FA can be considered as a vulnerability biomarker for BD.

Predicting change in diagnosis from major depression to bipolar disorder after antidepressant initiation

We aimed to develop and validate classification models able to identify individuals at high risk for transition from a diagnosis of depressive disorder to one of bipolar disorder. This retrospective health records cohort study applied outpatient clinical data from psychiatry and nonpsychiatry practice networks affiliated with two large academic medical centers between March 2008 and December 2017. Participants included 67,807 individuals with a diagnosis of major depressive disorder or depressive disorder not otherwise specified and no prior diagnosis of bipolar disorder, who received at least one of the nine antidepressant medications. The main outcome was at least one diagnostic code reflective of a bipolar disorder diagnosis within 3 months of index antidepressant prescription. Logistic regression and random forests using diagnostic and procedure codes as well as sociodemographic features were used to predict this outcome, with discrimination and calibration assessed in a held-out test set and then a second academic medical center. Among 67,807 individuals who received at least one antidepressant medication, 925 (1.36%) subsequently received a diagnosis of bipolar disorder within 3 months. Models incorporating coded diagnoses and procedures yielded a mean area under the receiver operating characteristic curve of 0.76 (ranging from 0.73 to 0.80). Standard supervised machine learning methods enabled development of discriminative and transferable models to predict transition to bipolar disorder. With further validation, these scores may enable physicians to more precisely calibrate follow-up intensity for high-risk patients after antidepressant initiation.

Use of long acting antipsychotics and relationship to newly diagnosed bipolar disorder: a pragmatic longitudinal study based on a Canadian health registry

BACKGROUND

There is limited data from large naturalistic studies to inform prescribing of long-acting injectable medication (LAIs). Guidance is particularly rare in the case of primary mood disorders.

METHODS

This study describes prescribing trends of LAIs in 3879 patients in Quebec, Canada, over a period of 4 years. Health register data from the Quebec provincial health plan were reviewed.

RESULTS

In this specific registry, 32% of patients who received LAIs drugs for schizophrenia had a confirmed diagnosis of bipolar disorder and 17% had a diagnosis of major depressive disorder. Non-schizophrenia syndromes were preferentially prescribed risperidone long-acting antipsychotic, whereas patients with schizophrenia were prescribed an excess of haloperidol decanoate. Patients with non-schizophrenia disorders prescribed long-acting antipsychotics were more frequently treated in primary care compared with patients with schizophrenia.

CONCLUSION

Data from a large number of patients treated naturalistically in Quebec with long-acting antipsychotics suggests that these compounds, prescribed to treat symptoms of schizophrenia and schizoaffective disorders, were maintained when mood symptoms emerged, even in cases when the diagnosis changed to bipolar disorder. This pragmatic study supports the need to explore this intervention as potential treatment for affective disorders.

An International Society of Bipolar Disorders task force report: Precursors and prodromes of bipolar disorder

OBJECTIVES

To clarify the clinical features preceding the onset of bipolar disorder (BD) has become a public health priority for the prevention of high morbidity and mortality. BD remains frequently under- or misdiagnosed, and under- or mistreated, often for years.

METHODS

We assessed the predictive value of precursors and prodromes of BD. We assessed precursors of first-lifetime manic or hypomanic episodes with/without mixed features in retrospective and prospective studies. The task force evaluated and summarized separately assessments of familial risk, premorbid personality traits, retrospective, and prospective studies.

RESULTS

Cyclothymic features, a family history of BD, retrospectively reported attenuated manic symptoms, prospectively identified subthreshold symptoms of hypomania, recurrence of depression, panic anxiety and psychotic features, have been identified as clinical precursors of BD. The prodromal symptoms like [hypo]mania often appears to be long enough to encourage early identification and timely intervention.

CONCLUSIONS

The predictive value of any risk factor identified remains largely unknown. Prospective controlled studies are urgently needed for prevention and effective treatment.

Gene expression pattern of CCL2, CCL3, and CXCL8 in patients with bipolar disorder

Background

Bipolar disorder (BD) is one of the most important psychiatric disorders in the world. There is evidence suggesting the role of inflammatory mediators such as chemokines in the etiology of BD. The objective of the current study was to evaluate the gene expression of CCL2, CCL3, and CXCL8 in patients with BD and compare them to healthy controls.

Materials and Methods

A total of 48 patients with confirmed BD and 48 healthy controls enrolled in this study. All patients were recruited from April to August 2016 at Ibn-Sina Psychiatric Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. RNA was extracted from the whole blood samples and then cDNA was synthesized. Gene expression of CCL2, CCL3, and CXCL8 was measured using SYBR^® Green real-time polymerase chain reaction. The difference of delta-CT values between patients and healthy controls was compared with the independent samples t-tests.

Results

CCL2 and CXCL8 genes expressed at higher levels in patients with BD as compared to healthy controls, but not significant. On the contrary, we found lower expression levels for CCL3 gene in our patients compared to healthy controls, but the difference was not statistically significant.

Conclusion

Our findings do not show an association between the gene expression of CCL2, CCL3 and CXCL8 and BD. Increasing the sample size and evaluation on the gene expression of other chemokines in depression and mania phases of BD might be helpful to get a better conclusion.

Variation in the CACNB2 gene is associated with functional connectivity of the Hippocampus in bipolar disorder

BACKGROUND

Calcium voltage-gated channel auxiliary subunit β2 is a protein that, in humans, is encoded by the CACNB2 gene. The β2 subunit is an auxiliary protein of voltage-gated calcium channels, which is predominantly expressed in hippocampal pyramidal neurons. A single-nucleotide polymorphism at the CACNB2 gene (rs11013860) has been reported in genome-wide association studies to be associated with bipolar disorder (BD). However, the neural effects of rs11013860 expression are unknown. Thus, the current study investigated the mechanisms of how the CACNB2 gene influences hippocampal-cortical limbic circuits in patients with bipolar disorder (BD).

METHODS

A total of 202 subjects were studied [69 BD patients and 133 healthy controls (HC)]. Participants agreed to undergo resting-state functional magnetic resonance imaging (rs-fMRI) and have blood drawn for genetic testing. Participants were found to belong to either a CC group homozygous for the C-allele (17 BD, 41 HC), or an A-carrier group carrying the high risk A-allele (AA/CA genotypes; 52 BD, 92 HC). Brain activity was assessed using resting-state functional connectivity (rs-FC) analyses.

RESULTS

A main effect of genotype showed that the rs-FC of the AA/CA group was elevated more than that of the CC-group between the hippocampus and the regions of right-inferior temporal, fusiform, and left-inferior occipital gyri. Additionally, a significant diagnosis × genotype interaction was noted between the hippocampus and right pars triangularis. Furthermore, in BD patients, the AA/CA group showed lower rs-FC when compared to that of the CC group. Additionally, individuals from HC within the AA/CA group showed higher rs-FC than that of the CC group. Finally, within C-allele-carrying groups, individuals with BD showed significantly increased rs-FC compared to that of HC.

CONCLUSIONS

Our study demonstrates that BD patients with the CACNB2 rs11013860 AA/CA genotype may exhibit altered hippocampal-cortical connectivity.

Pharmacological treatment of adult bipolar disorder

We summarize evidence supporting contemporary pharmacological treatment of phases of BD, including: mania, depression, and long-term recurrences, emphasizing findings from randomized, controlled trials (RCTs). Effective treatment of acute or dysphoric mania is provided by modern antipsychotics, some anticonvulsants (divalproex and carbamazepine), and lithium salts. Treatment of BD-depression remains unsatisfactory but includes some modern antipsychotics (particularly lurasidone, olanzapine + fluoxetine, and quetiapine) and the anticonvulsant lamotrigine; value and safety of antidepressants remain controversial. Long-term prophylactic treatment relies on lithium, off-label use of valproate, and growing use of modern antipsychotics. Lithium has unique evidence of antisuicide effects. Methods of evaluating treatments for BD rely heavily on meta-analysis, which is convenient but with important limitations. Underdeveloped treatment for BD-depression may reflect an assumption that effects of antidepressants are similar in BD as in unipolar major depressive disorder. Effective prophylaxis of BD is limited by the efficacy of available treatments and incomplete adherence owing to adverse effects, costs, and lack of ongoing symptoms. Long-term treatment of BD also is limited by access to, and support of expert, comprehensive clinical programs. Pursuit of improved, rationally designed pharmacological treatments for BD, as for most psychiatric disorders, is fundamentally limited by lack of coherent pathophysiology or etiology.

Attention deficit-hyperactivity disorder in adult bipolar disorder patients

BACKGROUND

It has long been recognized that bipolar disorder (BD) and attention deficit-hyperactivity disorder (ADHD) co-occur in an uncertain proportion of patients, recognized commonly in juvenile years. There is growing suspicion that such co-occurrence is associated with several clinically unfavorable characteristics. Accordingly, we compared 703 type I or II BD subjects with vs. without a lifetime diagnosis of ADHD.

METHODS

We compared 173 BD patients with vs. 530 without co-occurring ADHD for selected demographic and clinical factors, using standard initial bivariate comparisons followed by multivariable logistic regression modeling.

RESULTS

ADHD was found in 25% of BD subjects, more among men and with type I BD. Those with ADHD had higher scores at the Adult ADHD Self-Report Scale (ASRS), were more likely to have had less successful school performance, unemployment, lower socioeconomic status, less marriage and more divorce, as well as more substance abuse, suicide attempts, and [hypo]mania, but were less likely to have an anxiety disorder or a family history of mood disorder. Multivariable logistic regression modeling found six factors differing between BD subjects with versus without ADHD: less education after high school, higher ASRS score for inattention, ever separated or divorced, irritable temperament, male sex, and lower scores on the Hamilton Depression Rating Scale (HDRS) at intake.

COMMENTS

Co-occurrence of ADHD with BD was identified at a moderate rate, and was associated with several unfavorable outcomes as well as a tendency toward [hypo]mania.

A Risk Calculator for Bipolar Disorder in Youth: Improving the Odds for Personalized Prevention and Early Intervention?

There have been many longitudinal studies examining biological and environmental risk factors for developing bipolar disorder in youth. Specifically, well-established risk factors for bipolar disorder in children and adolescents include having a family history of bipolar disorder, depression, disruptive behavior disorders, psychosis, antidepressant-induced manic symptoms, anxiety, and subsyndromal symptoms of mania and depression.¹ In an effort to identify individuals at highest risk for developing bipolar disorder, several investigators have attempted to characterize a bipolar prodrome. A recent meta-analysis of early manifestations of bipolar disorder in youth found that the most common prodromal symptoms were increased energy, diminished ability to think, indecision, pressured speech, talkativeness, elated mood, academic or work difficulties, insomnia, depressed mood, and increased goal-directed activities.² The authors concluded that despite many of the participants having symptoms prior to their illness onset, there was significant heterogeneity in symptom presentation, making it difficult to define a consistent bipolar prodrome. Although it is important to explore risk factors and rates of early symptoms of incipient bipolar disorder, to date, most studies have examined risk within an entire group rather than quantified an individual's risk of having bipolar disorder, which is essential to advance personalized monitoring and treatment strategies.