Neurobiological correlates of illness progression in the recurrent affective disorders

Bipolar disorders and schizophrenia: discrete disorders?

Background

With similarities in heritability, neurobiology and symptomatology, the question has been raised whether schizophrenia and bipolar disorder are truly distinctive disorders or belong to a continuum. This narrative review summarizes common and distinctive findings from genetics, neuroimaging, cognition and clinical course that may help to solve this ethiopathogenetic puzzle.

Methods

The authors conducted a literature search for papers listed in PubMed and Google Scholar, using the search terms "schizophrenia" and "bipolar disorder" combined with different terms such as "genes", "neuroimaging studies", "phenomenology differences", "cognition", "epidemiology". Articles were considered for inclusion if they were written in English or Spanish, published as full articles, if they compared subjects with schizophrenia and bipolar disorder, or subjects with either disorder with healthy controls, addressing differences between groups.

Results

Several findings support the hypothesis that schizophrenia and bipolar disorder are discrete disorders, yet some overlapping of findings exists. The evidence for heritability of both SZ and BD is obvious, as well as the environmental impact on individual manifestations of both disorders. Neuroimaging studies support subtle differences between disorders, it appears to be rather a pattern of irregularities than an unequivocally unique finding distinguishing schizophrenia from bipolar disorder. The cognitive profile displays differences between disorders in certain domains, such as premorbid intellectual functioning and executive functions. Finally, the timing and trajectory of cognitive impairment in both disorders also differs.

Conclusion

The question whether SZ and BD belong to a continuum or are separate disorders remains a challenge for further research. Currently, our research tools may be not precise enough to carve out distinctive, unique and undisputable differences between SZ and BD, but current evidence favors separate disorders. Given that differences are subtle, a way to overcome diagnostic uncertainties in the future could be the application of artificial intelligence based on BigData.

Limitations

Despite the detailed search, this article is not a full and complete review of all available studies on the topic. The search and selection of papers was also limited to articles in English and Spanish. Selection of papers and conclusions may be biased by the personal view and clinical experience of the authors.

Staging models applied in a sample of patients with bipolar disorder: Results from a retrospective cohort study

BACKGROUND

Bipolar Disorder (BD) is a life-long illness with compelling evidence of progression. Although different staging models have been proposed to evaluate its course, clinical data remain limited. The aim of the present study was to retrospectively assess applicability of available staging approaches and their pattern of progression in a sample of bipolar patients.

METHODS

In a naturalistic sample of 100 BD patients, retrospective assessment of clinical stages was performed at four time points over 10 years, according to four staging models. Staging progression with potential associations between stages and unfavourable illness characteristics were analyzed.

RESULTS

A pattern of stage worsening emerged for each model, with a significant increase at every time point. Greater stage increases emerged in patients with lower educational level, age at first elevated episode ≤35 years, duration of illness ≤25 years, and duration of untreated illness ≤5 years. Lower stage values were associated with BD II, no psychiatric hospitalization, depressive onset and predominant polarity, ≤three lifetime episodes, age at first mood stabilizer >40 years, duration of illness ≤25 years, and engaged/employed status. Higher stage values were associated with lower age at first elevated episode and mood stabilizing treatment instead.

LIMITATIONS

Naturalistic and retrospective design, recruitment at a 2nd level specialistic clinic.

CONCLUSIONS

Reported findings support the progressive nature of BD and the application of staging models for early intervention, suggesting a conceptualization of a standardized approach to better characterize patients, predict their clinical course, and deliver tailored treatment options.

Elevation of C-reactive protein in adolescent bipolar disorder vs. anxiety disorders

Bipolar disorder (BD) largely begins in adolescence, but diagnosis lags for years, causing significant morbidity and mortality, and demonstrating the need for better diagnostic tools. Suggesting an association between BD and immune activity, elevated levels of peripheral inflammatory markers, including C-reactive protein (CRP), have been found in adults with BD. As similar data are extremely limited in adolescents, this study examined CRP levels in adolescents with BD (n = 37) compared to those with anxiety disorders (ADs, n = 157) and healthy controls with no psychiatric diagnoses (HCs, n = 2760). CRP blood levels for patients aged 12-17 years were retrieved from a nationwide repository of deidentified clinical data. After excluding patients with inflammatory conditions, differences in CRP were examined using multivariate and weighted regressions (covariates: demographics and BMI). Mean CRP levels were significantly elevated in adolescents with BD relative to those with ADs and HCs. Mean CRP levels were lower in the ADs cohort versus HCs. Although CRP levels were significantly higher in males and younger patients, the significant between-cohort differences in CRP remained after controlling for multiple confounders. To our knowledge, our study is the first to compare CRP levels between adolescent BD, ADs, and HCs, comprising a novel and essential contribution. Our results suggest the presence of a unique immune process in adolescents with BD and indicate that CRP may represent a biomarker with a crucial role in the diagnostic assessment of adolescent BD.

Smartphone-based interventions in bipolar disorder: Systematic review and meta-analyses of efficacy. A position paper from the International Society for Bipolar Disorders (ISBD) Big Data Task Force

BACKGROUND

The clinical effects of smartphone-based interventions for bipolar disorder (BD) have yet to be established.

OBJECTIVES

To examine the efficacy of smartphone-based interventions in BD and how the included studies reported user-engagement indicators.

METHODS

We conducted a systematic search on January 24, 2022, in PubMed, Scopus, Embase, APA PsycINFO, and Web of Science. We used random-effects meta-analysis to calculate the standardized difference (Hedges' g) in pre-post change scores between smartphone intervention and control conditions. The study was pre-registered with PROSPERO (CRD42021226668).

RESULTS

The literature search identified 6034 studies. Thirteen articles fulfilled the selection criteria. We included seven RCTs and performed meta-analyses comparing the pre-post change in depressive and (hypo)manic symptom severity, functioning, quality of life, and perceived stress between smartphone interventions and control conditions. There was significant heterogeneity among studies and no meta-analysis reached statistical significance. Results were also inconclusive regarding affective relapses and psychiatric readmissions. All studies reported positive user-engagement indicators.

CONCLUSION

We did not find evidence to support that smartphone interventions may reduce the severity of depressive or manic symptoms in BD. The high heterogeneity of studies supports the need for expert consensus to establish ideally how studies should be designed and the use of more sensitive outcomes, such as affective relapses and psychiatric hospitalizations, as well as the quantification of mood instability. The ISBD Big Data Task Force provides preliminary recommendations to reduce the heterogeneity and achieve more valid evidence in the field.

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.

Are personality disorders in bipolar patients more frequent in the US than Europe?

OBJECTIVE

Bipolar patients in the United States (US) compared to those from the Netherlands and Germany (here abbrev. as "Europe") have more Axis I comorbidities and more poor prognosis factors such as early onset and psychosocial adversity in childhood. We wished to examine whether these differences also extended to Axis II personality disorders (PDs).

METHODS

793 outpatients with bipolar disorder diagnosed by SCID gave informed consent for participating in a prospective longitudinal follow up study with clinician ratings at each visit. They completed detailed patient questionnaires and a 99 item personality disorder inventory (PDQ-4). US versus European differences in PDs were examined in univariate analyses and then logistic regressions, controlling for severity of depression, age, gender, and other poor prognosis factors.

RESULTS

In the univariate analysis, 7 PDs were more prevalent in the US than in Europe, including antisocial, avoidant, borderline, depressive, histrionic, obsessive compulsive, and schizoid PDs. In the multivariate analysis, the last 4 of these PDs remained independently greater in the US than Europe.

CONCLUSIONS

Although limited by use of self report and other potentially confounding factors, multiple PDs were more prevalent in the US than in Europe, but these preliminary findings need to be confirmed using other methodologies. Other poor prognosis factors are prevalent in the US, including early age of onset, more childhood adversity, anxiety and substance abuse comorbidity, and more episodes and rapid cycling. The interactions among these variables in relationship to the more adverse course of illness in the US than in Europe require further study.

Malondialdehyde as a candidate biomarker for bipolar disorder: A meta-analysis

Malondialdehyde (MDA) represents one of the final products of lipid peroxidation that is thought to be enhanced and accelerated in patients affected by bipolar disorder (BD). Purpose of the present article is to critically summarize the available data about MDA as a candidate biomarker for BD. First, we carried out a systematic review of the literature selecting those papers that evaluated MDA levels in BD. Then, we performed two separate meta-analyses: one of the studies that compared healthy controls (HC) with unmedicated BD and one with the studies that assessed MDA levels before and after treatment in BD, showing that bipolar patients experience more oxidative stress than healthy subjects and that treatment is effective in reducing MDA levels. In the first set of studies, we also explored through a meta-regression whether age, gender and experiencing an episode specifically influenced the difference between BD and HC in MDA levels. Bipolar patients compared to healthy subjects had higher MDA levels (SMD: 0.94, 95% CI: 0.23-1.64). Age (p < 0.01), gender (p < 0.01) and the presence of a current mood episode (p < 0.01) significantly influenced MDA plasma/serum levels. Specifically, studies that included more female, older subjects and more BD in euthymia were more likely to have higher MDA levels. Finally, patients after treatment had lower levels of MDA compared to baseline (SMD: -0.52, 95% CI: -0.85 -0.19). More studies are needed to draw definitive conclusions.

Lipophilic vs. hydrophilic statins and psychiatric hospitalizations and emergency room visits in US Veterans with schizophrenia and bipolar disorder

Objective –

Psychiatric hospitalizations and emergency department (ED) visits are costly, stigmatizing, and often ineffective. Given the immune and kynurenine activation in bipolar disorder (BD) and schizophrenia, as well as the immune-modulatory effects of statins, we aimed to compare the relative risk (RRs) of psychiatric hospitalizations and ED visits between individuals prescribed lipophilic vs. hydrophilic statins vs. no statins. We hypothesized (a) reduced rates of hospitalization and ER utilization with statins versus no statins and (b) differences in outcomes between statins, as lipophilia increases the capability to penetrate the blood–brain barrier with potentially beneficial neuroimmune, antioxidant, neuroprotective, neurotrophic, and endothelial stabilizing effects, and, in contrast, potentially detrimental decreases in brain cholesterol concentrations leading to serotoninergic dysfunction, changes in membrane lipid composition, thus affecting ion channels and receptors.

Methods –

We used VA service utilization data from October 1, 2010 to September 30, 2015. The RRs for psychiatric hospitalization and ED visits, were estimated using robust Poisson regression analyses. The number of individuals analyzed was 683,129.

Results –

Individuals with schizophrenia and BD who received prescriptions for either lipophilic or hydrophilic statins had a lower RR of psychiatric hospitalization or ED visits relative to nonstatin controls. Hydrophilic statins were significantly associated with lower RRs of psychiatric hospitalization but not of ED visits, compared to lipophilic statins.

Conclusion –

The reduction in psychiatric hospitalizations in statin users (vs. nonusers) should be interpreted cautiously, as it carries a high risk of confounding by indication. While the lower RR of psychiatric hospitalizations in hydrophilic statins relative to the lipophilic statins is relatively bias free, the finding bears replication in a specifically designed study. If replicated, important clinical implications for personalizing statin treatment in patients with mental illness, investigating add-on statins for improved therapeutic control, and mechanistic exploration for identifying new treatment targets are natural next steps.

Exploring Signatures of Neurodegeneration in Early-Onset Older-Age Bipolar Disorder and Behavioral Variant Frontotemporal Dementia

Introduction: Older-age bipolar disorder (OABD) may involve neurocognitive decline and behavioral disturbances that could share features with the behavioral variant of frontotemporal dementia (bvFTD), making the differential diagnosis difficult in cases of suspected dementia.

Objective: To compare the neuropsychological profile, brain morphometry, and structural connectivity patterns between patients diagnosed with bvFTD, patients classified as OABD with an early onset of the disease (EO-OABD), and healthy controls (HC).

Methods: bvFTD patients (n = 25, age: 66 ± 7, female: 64%, disease duration: 6 ± 4 years), EO-OABD patients (n = 17, age: 65 ± 9, female: 71%, disease duration: 38 ± 8 years), and HC (n = 28, age: 62 ± 7, female: 64%) were evaluated through neuropsychological tests concerning attention, memory, executive function, praxis, and language. Brain morphometry was analyzed through surface-based morphometry (SBM), while structural brain connectivity was assessed through diffusion tensor imaging (DTI).

Results: Both bvFTD and EO-OABD patients showed lower performance in neuropsychological tests of attention, verbal fluency, working memory, verbal memory, and praxis than HC. Comparisons between EO-OABD and bvFTD showed differences limited to cognitive flexibility delayed recall and intrusion errors in the memory test. SBM analysis demonstrated that several frontal, temporal, and parietal regions were altered in both bvFTD and EO-OABD compared to HC. In contrast, comparisons between bvFTD and EO-OABD evidenced differences exclusively in the right temporal pole and the left entorhinal cortex. DTI analysis showed alterations in association and projection fibers in both EO-OABD and bvFTD patients compared to HC. Commissural fibers were found to be particularly affected in EO-OABD. The middle cerebellar peduncle and the pontine crossing tract were exclusively altered in bvFTD. There were no significant differences in DTI analysis between EO-OABD and bvFTD.

Discussion: EO-OABD and bvFTD may share an overlap in cognitive, brain morphometry, and structural connectivity profiles that could reflect common underlying mechanisms, even though the etiology of each disease can be different and multifactorial.

Mitochondrial dysfunction as a critical event in the pathophysiology of bipolar disorder

The understanding of the pathophysiology of bipolar disorder (BD) remains modest, despite recent advances in neurobiological research. The mitochondrial dysfunction hypothesis of bipolar disorder has been corroborated by several studies involving postmortem brain analysis, neuroimaging, and specific biomarkers in both rodent models and humans. Evidence suggests that BD might be related to abnormal mitochondrial morphology and dynamics, neuroimmune dysfunction, and atypical mitochondrial metabolism and oxidative stress pathways. Mitochondrial dysfunction in mood disorders is also associated with abnormal Ca2+ levels, glutamate excitotoxicity, an imbalance between pro- and antiapoptotic proteins towards apoptosis, abnormal gene expression of electron transport chain complexes, and decreased ATP synthesis. This paper aims to review and discuss the implications of mitochondrial dysfunction in BD etiology and to explore mitochondria as a potential target for novel therapeutic agents.

Neuroprogression as an Illness Trajectory in Bipolar Disorder: A Selective Review of the Current Literature

Bipolar disorder (BD) is a chronic and disabling psychiatric condition that is linked to significant disability and psychosocial impairment. Although current neuropsychological, molecular, and neuroimaging evidence support the existence of neuroprogression and its effects on the course and outcome of this condition, whether and to what extent neuroprogressive changes may impact the illness trajectory is still poorly understood. Thus, this selective review was aimed toward comprehensively and critically investigating the link between BD and neurodegeneration based on the currently available evidence. According to the most relevant findings of the present review, most of the existing neuropsychological, neuroimaging, and molecular evidence demonstrates the existence of neuroprogression, at least in a subgroup of BD patients. These studies mainly focused on the most relevant effects of neuroprogression on the course and outcome of BD. The main implications of this assumption are discussed in light of specific shortcomings/limitations, such as the inability to carry out a meta-analysis, the inclusion of studies with small sample sizes, retrospective study designs, and different longitudinal investigations at various time points.

The Kindling/Sensitization Model and Early Life Stress

INTRODUCTION

Few animal models address the characteristics of the longitudinal course of bipolar disorder. However, behavioral sensitization (to recurrent stressors and psychomotor stimulants) and kindling of seizures both provide clues to mechanisms in the progressive course of bipolar disorder.

METHODS

We describe aspects of bipolar illness that show sensitization and kindling-like increases reactivity to the recurrence of stressors, mood episodes, and bouts of substance abuse. Mechanisms of these events and clinical implications for treatment are discussed.

RESULTS

Early life stress is a risk factor for the development of episodes of unipolar depression and bipolar disorder and the acquisition of substance abuse. Initial affective episodes are often triggered by the recurrence of psychosocial stressors in adulthood, but after many episodes have occurred, episodes may also begin to emerge spontaneously in a kindling-like progression. More prior episodes are associated with faster recurrences, dysfunction, disability, frontal cortical abnormalities, cognitive impairment, shorter telomeres, treatment refractoriness, and an increased risk of a diagnosis of dementia in old age. Sensitization to stressors, episodes, and substances of abuse each appear driven by epigenetic mechanisms and their accumulation on DNA, histones, and microRNA. Patients with bipolar illness in the USA are more ill than those from Europe and experience more sensitization to stressors, episodes, substance abuse, as well as more genetic vulnerability across four generations.

DISCUSSION

The sensitization and kindling models highlight the importance of early intervention and prevention in order to limit or halt the downhill progression of bipolar disorder and its multiple comorbidities toward treatment refractoriness. Clinical data support this conclusion as well but have not been sufficient to change practice in the direction of early intervention. It is hoped that a better understanding of sensitization and kindling-like mechanisms will add neurobiological rationales for the importance of prevention and sustained prophylactic intervention in rendering bipolar disorder a more benign illness.

Neurobiology of bipolar disorders: a review of genetic components, signaling pathways, biochemical changes, and neuroimaging findings

Bipolar disorder (BD) is a chronic mental illness characterized by changes in mood that alternate between mania and hypomania or between depression and mixed states, often associated with functional impairment. Although effective pharmacological and non-pharmacological treatments are available, several patients with BD remain symptomatic. The advance in the understanding of the neurobiology underlying BD could help in the identification of new therapeutic targets as well as biomarkers for early detection, prognosis, and response to treatment in BD. In this review, we discuss genetic, epigenetic, molecular, physiological and neuroimaging findings associated with the neurobiology of BD. Despite the advances in the pathophysiological knowledge of BD, the diagnosis and management of the disease are still essentially clinical. Given the complexity of the brain and the close relationship between environmental exposure and brain function, initiatives that incorporate genetic, epigenetic, molecular, physiological, clinical, environmental data, and brain imaging are necessary to produce information that can be translated into prevention and better outcomes for patients with BD.

How to prevent the malignant progression of bipolar disorder

There is increasing recognition that, in a high percentage of cases, bipolar disorder is a progressive illness. Multiple types of sensitization (or increased reactivity to repetition of the same stimulus) drive illness progression. One of the clearest is that of episode sensitization, where increased numbers of prior episodes are associated with: faster recurrences; more dysfunction; disability; social, educational, and employment deficits; suicide; medical comorbidities; cognitive dysfunction; and an increased incidence of dementia in old age. Repetition of stressors and bouts of substance abuse can also result in sensitization. Each type of sensitization appears to have an epigenetic basis, such that preventing sensitization should minimize the accumulation of adverse epigenetic chemical marks on DNA, histones, and microRNA. New data emphasize the importance of early, consistent intervention after an initial manic episode. The cognitive dysfunction associated with a first episode improves only if there are no further episode recurrences during the next year. A randomized study has also shown that comprehensive multimodal prophylactic intervention for 2 years leads to improvements in illness course extending over a total of 6 years. Intensive treatment of the earliest stages of bipolar disorder can thus exert lasting positive effects on the course of illness.

The influence of stage of illness on functional outcomes after psychological treatment in bipolar disorder: A systematic review

OBJECTIVES

The aim of this study was to advance understanding of stage of illness in bipolar disorder (BD), by interrogating the literature for evidence of an influence of stage of illness on functional (ie non-symptom) outcomes following psychosocial intervention.

METHODS

A systematic literature search following PRISMA guidelines was conducted to identify empirical studies of psychosocial interventions for established BD. To investigate stage as a predictor of three functional outcomes (general/social functioning, cognitive functioning and quality of life [QoL]), study samples were dichotomised into earlier and later stage using proxy measures identified in existing staging models. Findings were integrated using data-based convergent synthesis.

RESULTS

A total of 88 analyses from 62 studies were identified. Synthesis across studies suggested that psychosocial intervention was more likely to be effective for general functioning outcomes earlier in the course of established BD. No stage-related differences were found for cognitive or QoL outcomes. Exploratory investigations found some evidence of an interaction between specific intervention type and stage of illness in predicting outcomes.

CONCLUSIONS

A novel systematic review provided preliminary evidence that benefits general/social functioning may be more pronounced in earlier versus later stages of established BD. The review also generated hypotheses about a potential three-way interaction, whereby specific psychosocial interventions may be best placed to target functional outcomes in earlier versus later stage BD. The strength of conclusions is limited by the overall low-quality and significant heterogeneity of studies. Further research is urgently required to understand the impact of illness stage on the effectiveness of psychosocial interventions.

Toward prevention of bipolar disorder in at-risk children: Potential strategies ahead of the data

BACKGROUND

Despite the well-documented negative impact of untreated bipolar illness, approaches to early intervention in childhood-onset bipolar and related disorders are not well delineated.

METHODS

We reviewed the extant treatment literature on children at high risk for bipolar disorder, with definitions based on family history, childhood adversity, and prodromal symptoms.

RESULTS

A panoply of approaches have been described, but most interventions are based on an inadequate database to support their routine implementation. We classify early stage interventions as a function of their safety and tolerability with the hope that these might generate more rigorous study and a stronger database.

LIMITATIONS

Critics may rightly argue that identifying viable treatment methods is premature given our lack of ability to reliably predict illness trajectory in very young children. However, many of the psychosocial and pharmacological interventions we present could have nonspecific positive effects across a variety of symptoms, syndromes, and diagnoses, further enhancing the rationale for more rigorous study.

CONCLUSIONS

Early stage interventions have the potential to improve functioning in prodromal illness and exert long-term positive effects on the course of illness. Many of the safest interventions deserve consideration for implementation and dissemination studies.

Predictive factors of functional outcome in patients with bipolar I disorder: a five-year follow-up

BACKGROUND

Functional impairment is commonly encountered among patients with bipolar disorder (BD) during periods of remission. The distribution of the impairment of the functional outcome is heterogeneous. The objective of this current investigation was to identify neurocognitive and clinical predictors of psychosocial functioning in a sample of patients with BD.

METHODS

Seventy-six patients (59.2% females) and 40 healthy controls (50% females), aged 18 to 55 years, were assessed using a comprehensive neurocognitive battery (six neurocognitive domains), and the Functioning Assessment Short Test (FAST), at baseline and after a 5-year follow-up. Stepwise regression models were used to identify predictor variables related to psychosocial functioning.

RESULTS

The number of hospitalizations during the follow-up, the change occurred in the neurocognitive composite index (NCI change), and NCI at baseline explained 30.8% of the variance of functioning. The number of hospitalizations during the follow-up was the variable that explained a greater percentage of the variance (16.9%). Verbal memory at baseline and the change in sustained attention during the follow-up explained 10% and 5.9% of the variance of the psychosocial functioning, respectively.

LIMITATIONS

The interval of 5 years between the two assessments could be too short to detect a possible progression in functional outcome for the overall sample.

CONCLUSIONS

The clinical course during the follow-up is the factor that has a greater impact on psychosocial functioning in patients with BD. Thus, the interventions aimed to promote prevention of relapses should be considered as essential for avoiding functional impairment in these patients.

Amygdala subnuclei volume in bipolar spectrum disorders: Insights from diffusion-based subsegmentation and a high-risk design

Amygdala abnormalities are widely documented in bipolar spectrum disorders (BSD). Amygdala volume typically is measured after BSD onset; thus, it is not known whether amygdala abnormalities predict BSD risk or relate to the disorder. Additionally, past literature often treated the amygdala as a homogeneous structure, and did not consider its distinct subnuclei and their differential connectivity to other brain regions. To address these issues, we used a behavioral high‐risk design and diffusion‐based subsegmentation to examine amygdala subnuclei among medication‐free individuals with, and at risk for, BSD. The behavioral high‐risk design (N = 114) included low‐risk (N = 37), high‐risk (N = 47), and BSD groups (N = 30). Diffusion‐based subsegmentation of the amygdala was conducted to determine whether amygdala volume differences related to particular subnuclei. Individuals with a BSD diagnosis showed greater whole, bilateral amygdala volume compared to Low‐Risk individuals. Examination of subnuclei revealed that the BSD group had larger volumes compared to the High‐Risk group in both the left medial and central subnuclei, and showed larger volume in the right lateral subnucleus compared to the Low‐Risk group. Within the BSD group, specific amygdala subnuclei volumes related to time since first episode onset and number of lifetime episodes. Taken together, whole amygdala volume analyses replicated past findings of enlargement in BSD, but did not detect abnormalities in the high‐risk group. Examination of subnuclei volumes detected differences in volume between the high‐risk and BSD groups that were missed in the whole amygdala volume. Results have implications for understanding amygdala abnormalities among individuals with, and at risk for, a BSD.

Number of episodes in bipolar disorder: The case for more thoughtful conceptualization and measurement

OBJECTIVES

Number of mood episodes (NoE) may be an important prognostic indicator in bipolar disorder, with implications for treatment. However, NoE has been conceptualized and measured inconsistently throughout the literature. This review examines the construct of NoE in bipolar disorder, with the aim of enhancing its conceptualization and measurement.

METHODS

A critical evaluation of literatures on important correlates of NoE, conceptually and phenomenologically overlapping features, and previous studies considering and measuring this construct was undertaken.

RESULTS

The literature indicates that despite frequent use, NoE has been inconsistently defined and measured. Multiple studies have linked NoE with important clinical factors, including relapse, functioning, cognitive impairment and the effectiveness of both pharmacological and psychosocial interventions, yet conclusions are limited by its inconsistent treatment. Additionally, it seems evident that that NoE may best be treated as a fuzzy construct (rather than precise figure), with yet to be defined overlaps with clinical variables such as age at onset and severity. Attempts to measure this construct have varied in comprehensiveness and structure.

CONCLUSIONS

The NoE construct may have important implications for individuals with bipolar disorders. However, more consistent and systematic definition and assessment of NoE is required to advance this literature and clarify its role. Recommendations aimed at advancing the conceptualization and the measurement of NoE are provided. Conceptualization may be advanced by considering and exploring relationships between NoE and factors with which it overlaps, while measurement may best be improved with increased consistency and balancing accuracy with feasibility.

Longitudinal analysis of cognitive performances in recent-onset and late-life Bipolar Disorder: A systematic review and meta-analysis

OBJECTIVES

Neurocognitive deficits have been widely reported in euthymic Bipolar Disorder (BD) patients and contribute to functional disability. However, the longitudinal trajectory of these deficits remains a subject of debate. Although most research to this date shows that neurocognitive deficits tend to be stable among middle-age BD patients, it remains plausible that deterioration occurs at either early or late stages of this condition.

METHODS

We conducted a comprehensive meta-analysis of studies that reported longitudinal neurocognitive performance among individuals with BD either within the year of their diagnosis or among late-life BD patients. Pooled effects of standardized mean differences (SMDs) for changes in neuropsychological scores over follow-up were estimated using random effects model. We also examined effect moderators, such as length of follow-up, mood state, or pharmacological load.

RESULTS

Eight studies met inclusion criteria for recent-onset and four studies for late-life BD analysis. No evidence for a deterioration in neurocognitive functioning was observed among recent-onset BD patients (8 studies, 284 patients, SMD: 0.12, 95% CI -0.06 to 0.30, mean follow-up: 17 months) nor for late-life BD patients (4 studies, 153 patients, SMD: -0.35, 95% CI -0.84 to 0.15, mean follow-up: 33 months). None of the moderators were shown to be significant.

CONCLUSIONS

These results, when appraised together with the findings in middle-life BD patients and individuals at genetic risk for BD, suggest that neurodevelopmental factors might play a significant role in cognitive deficits in BD and do not support the notion of progressive cognitive decline in most patients with BD.

Cerebrospinal fluid oxidative stress metabolites in patients with bipolar disorder and healthy controls: a longitudinal case-control study

Bipolar disorder (BD) is a mental disorder characterized by recurrent relapses of affective episodes, cognitive impairment, illness progression, and reduced life expectancy. Increased systemic oxidatively generated nucleoside damage have been found in some neurodegenerative disorders and in BD. As the first, this naturalistic prospective, longitudinal follow-up case-control study investigated cerebrospinal fluid (CSF) oxidative stress markers 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) that relate to RNA and DNA damage, respectively. Patients with BD (n = 86, 51% female) and gender-and-age-matched healthy control individuals (HC; n = 44, 44% female) were evaluated at baseline (T0), during (T1) and after a new affective episode (T2), if it occurred, and after a year (T3). Cerebrospinal and urine oxidative stress markers were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. CSF-8-oxoGuo was statistically significantly higher by 18% (p = 0.003) in BD versus HC at T0, and by 22% (p = 0) at T3. CSF-8-oxoGuo had increased by 15% (p = 0.042) from T0 to T3, and by 14% (p = 0.021) from T2 to T3 in patients, who experienced an episode during follow-up. CSF-8-oxodG had increased by 26% (p = 0.054) from T0 to T2 and decreased by 19% (p = 0.041) from T2 to T3 in patients, who experienced an episode during follow-up. CSF-8-oxoGuo did not show a statistically significant change in HC during the one-year follow-up. CSF and urine-8-oxoGuo levels correlated moderately. In conclusion, CSF oxidative stress marker of RNA damage 8-oxoGuo showed both state and trait dependence in BD and stability in HC. Central RNA damage may be a potential biomarker for BD.

Neurophysiological effects of multiple mood episodes in bipolar disorder

OBJECTIVES

Bipolar disorder is marked by progressive symptomatic changes, which have been linked with episode-related structural findings-particularly in the prefrontal cortex. However, few studies have examined neurofunctional and neurochemical effects of disease burden. In this study, we compared first- and multi-episode bipolar individuals. We hypothesized that the latter would demonstrate evidence of neurophysiological differences consistent with a model of progressive functional degradation of these networks.

METHODS

First- and multi-episode manic bipolar subjects participated in functional magnetic resonance imaging (fMRI) including a continuous performance task with emotional distractors, and in single-voxel (¹ H) magnetic resonance spectroscopy (MRS). A priori fMRI regions-of-interest (ROI) included structures comprising prefrontal-striatal-amygdala networks; (¹ H)MRS voxels were placed within bilateral ventrolateral prefrontal (VLPFC) and anterior cingulate cortex (ACC). Both ROI and voxel-based brain activation in response to emotional stimuli, and neurochemical concentrations derived from (¹ H)MRS were compared across bipolar groups.

RESULTS

Multi-episode bipolar subjects showed relatively lower regional activation across prefrontal-striatal-amygdala networks, including bilateral VLPFC, orbitofrontal cortex, ACC, putamen, caudate, and amygdala. Exploratory whole-brain, voxel-based analysis suggested additional areas of lower activation extending into Brodmann area 22, posterior parietal regions, and right thalamus. Glutamate and N-acetylaspartate (NAA) concentrations were also relatively lower in the ACC of multi-episode subjects.

CONCLUSIONS

Disease burden, exemplified by multiple affective episodes is associated with evidence of widespread decrements in affective network activity. Lower ACC NAA concentration is similarly consistent with a model of progressive functional deficits. These findings support the functional significance of previously observed progressive structural changes throughout these regions.

Inflammation and depression but where does the inflammation come from?

PURPOSE OF REVIEW

Up until the latter part of the previous century, the monoamine theory guided our understanding of psychiatric disorders, notably depressive illness in its various phenotypic manifestations. The purpose of this review is to provide an overview of newer theories that allow a deeper understanding of brain dysfunction and neuropsychiatric disease entities such as depressive illness. One such key theory is the theory of inflammation as a result of stress-induced immune system activation.

RECENT FINDINGS

Stress activates the hypothalamic-pituitary-adrenal axis and the sympathetic branch of the autonomic nervous system [sympathetic branch (SNS)] with a concomitant reduction in vagal tone. This homeostatic imbalance makes a simultaneous dual contribution to the resulting proinflammatory state of depression. SNS stimulation results in upregulation of proinflammatory signaling, whereas diminution in parasympathetic tone affects the body's immune response. The resulting proinflammatory status has been closely associated with multiple organ dysfunction and comorbid conditions.

SUMMARY

The advent of innovative theories about the pathophysiology of psychiatric disorders has ushered in a new era on the basis of the role of the immune system and inflammation in mediating depression in its multifaceted manifestations. Extensive studies have confirmed the proinflammatory status in depression and causal relationships with neurotransmitter dysregulation. Equally importantly the role the autonomic nervous system plays in this complex and multifactorial interplay of body systems is being increasingly elucidated.

Predictors of recurrence in a sample of 508 outpatients with major depressive disorder

OBJECTIVE

Specific predictors of relapse/recurrence in major depressive disorder (MDD) have been identified but evidence across studies are inconsistent. This study aimed to identify the most relevant socio-demographic/clinical predictors of MDD recurrence in a sample of 508 outpatients.

METHODS

This naturalistic cohort study included 508 currently euthymic MDD patients (mean age = 54.1 ± 16.2) of which 53.9% had a single and 46.1% recurrent depressive episodes. A detailed data collection was performed and illness histories were retraced through clinical files and lifetime computerized medical records.

RESULTS

Compared to patients with single episode, MDD patients with recurrent episodes significantly differ regarding current age, gender, working status, positive history of psychiatric disorders in family, first-lifetime illness episode characteristics, first-episode and current psychotic symptoms, current melancholic features and seasonality, age at first treatment, duration of untreated illness, and comorbid cardiovascular/endocrinological conditions. However, after multivariate analyses controlling for current age, gender, educational level, working status differences, psychiatric conditions in family, and age of illness episode, recurrence was associated with older age (p ≤ .001), younger age at first treatment (p ≤ .005), being treated with previous psychoactive treatments (p .001), and longer duration of untreated illness (p .001).

CONCLUSIONS

The variables associated with MDD recurrence identified in the current study may aid in the stratification of patients who could benefit from more intensive maintenance treatments for MDD. However, clinicians should rapidly identify cases that are not likely to recur in order to avoid unnecessary treatments which are commonly considered as the standard of care.

Impact of number of episodes on neurocognitive trajectory in bipolar disorder patients: a 5-year follow-up study

BACKGROUND

The neurocognitive trajectory in bipolar disorder (BD) is variable, with controversial findings, and most evidence come from cross-sectional studies. We aimed to examine the course of neurocognitive functioning in a sample of euthymic BD patients in comparison with a control group during a 5-year follow-up.

METHODS

Ninety-nine euthymic bipolar patients and 40 healthy controls were assessed using a comprehensive neurocognitive battery (six neurocognitive domains) at baseline (T1) and then at 5-year follow-up (T2) in a longitudinal study.

RESULTS

No evidence of a progression in neurocognitive dysfunction was found either in cognitive composite index or in any of the neurocognitive domains for the whole cohort. However, there was a negative correlation between number of manic episodes and hospitalisations due to manic episodes and change in neurocognitive composite index (NCI) during the follow-up. Moreover, patients with higher number of manic and hypomanic episodes have a greater decrease in NCI, working memory and visual memory. History of psychotic symptoms was not related to the trajectory of neurocognitive impairment.

CONCLUSIONS

Our results suggest that, although the progression of cognitive decline is not a general rule in BD, BD patients who have a greater number of manic or hypomanic episodes may constitute a subgroup characterised by the progression of neurocognitive impairment. Prevention of manic and hypomanic episodes could have a positive impact on the trajectory of cognitive function.

Does stage of illness influence recovery-focused outcomes after psychological treatment in bipolar disorder? A systematic review protocol

BACKGROUND

There is great interest in the possibility that 'stage of illness' moderates treatment outcomes in bipolar disorder (BD). Much remains unknown about the construct of stage of illness, but there is evidence that effectiveness of psychosocial interventions may depend on factors that are plausible proxy measures of stage of illness (e.g., number of episodes). To date, reviews of this data have focused solely on clinical outcomes (particularly symptoms and relapse rates), but a range of recovery-focused outcomes (including functioning, cognitive functioning, and quality of life) have been measured in individuals with established BD. The aim of the proposed systematic review is to synthesise existing evidence for plausible proxy measures of stage of illness as moderators of recovery-focused and functional outcomes in psychosocial treatment studies of BD.

METHODS

The proposed review will follow PRISMA guidelines; Scopus, PsychINFO, PubMed and Web of Science will be searched for empirical studies of psychosocial interventions used for established (clinical stages 2-4) BD; and findings will be summarised in a narrative synthesis of clinical stage of illness (operationalised in proxy measures identified in existing staging models) as a moderator of recovery-focused and functional outcomes of psychosocial interventions for established bipolar disorder.

DISCUSSION

This review will contribute to the literature by expanding upon previous reviews and potentially inform the psychosocial treatment of established BD. Implications include assisting clinicians, consumers and researchers to identify and select interventions most appropriate to recovery-focused goals based on individuals' clinical status.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037868.

The level of IL-6 was associated with sleep disturbances in patients with major depressive disorder

Purpose: Major depression disorder (MDD) was associated with inflammatory processes, but association results of inflammatory syndrome and MDD were inconsistent. To provide more evidence, we measured the plasma levels of IL-1β, IL-6, interferon (INT)-α2, INT-γ, and tumor necrosis factor (TNF)-α in patients having MDD and explored correlations between the five proinflammatory cytokines and specific depressive symptoms. Patients and methods: Plasma concentrations of IL-1β, IL-6, INT-α2, INT-γ, and TNF-α were measured using ELISA for 44 MDD patients and 54 healthy controls. Patients with MDD were assessed on the 17-item Hamilton Depression Rating Scale (HAMD-17), and a total score and five syndrome scores were acquired. Results: IL-6 levels in depressed patients were significantly elevated than in healthy controls, but no significant differences were observed in the levels of INF-α2, INF-γ, IL-1β, or TNF-α. In addition, correlation analysis revealed that sleep disturbances positively correlated with IL-6. Although there was no significant difference between the two groups in the levels of INF-α2, a significant positive correlation between IFN-α2 and retardation was observed. Conclusion: Elevated IL-6 levels were observed in MDD patients and IL-6 may correlate with sleep disturbances.

Areas of uncertainties and unmet needs in bipolar disorders: clinical and research perspectives

This Review discusses crucial areas related to the identification, clinical presentation, course, and therapeutic management of bipolar disorder, a major psychiatric illness. Bipolar disorder is often misdiagnosed, leading to inappropriate, inadequate, or delayed treatment. Even when bipolar disorder is successfully diagnosed, its clinical management presents several major challenges, including how best to optimise treatment for an individual patient, and how to balance the benefits and risks of polypharmacy. We discuss the major unmet needs in the diagnosis and management of bipolar disorder in this Review, including improvement of adequate recognition and intervention in at-risk and early-disease stages, identification of reliable warning signs and prevention of relapses in unstable and rapid cycling patients, treatment of refractory depression, and prevention of suicide. Taken together, there are several promising opportunities for improving treatment of bipolar disorder to deliver medical care that is more personalised.

Neuroprogression: the hidden mechanism of depression

For many years, depressive disorder (DD) was considered a transient and natural disease of people's mood. Its etiology had been attributed mainly to biochemical alterations of the monoamines and their receptors. Nevertheless, its prevalence and considerable impact on the family and social environment of those afflicted by it have placed the disease as a global public health problem. Neuroprogression is the term used to describe the changes in several psychiatric conditions evidenced and observed in the clinical manifestations, biochemical markers, and cerebral structures of the patients with major depressive disorder (MDD), which frequently overlap with neurodegenerative disorders. DD is considered a potentially aggressive state of neuronal deterioration involving apoptosis, reduced neurogenesis, decreased neuronal plasticity, and increased immune response. Clinically, it encompasses a poor response to treatment and an increase in depressive episodes, both of which bring about vulnerability and decline of functions associated with structural changes in the brain. The interest of this work is to review the metabolic processes involved in the morphologic alterations in the limbic system reported in patients with MDD, as well as the neurologic bases of this complex pathology that include environmental stress, genetic vulnerability, alterations in the neurotransmission, and changes in the neuroplasticity, all of which today bring into limelight a mechanism of progressive neuronal damage.

Prevalence of axis II comorbidities in bipolar disorder: relationship to mood state

OBJECTIVES

A high incidence of Axis II personality disorders is described in patients with bipolar disorder; however, their relationship to mood state remains uncertain.

METHODS

A total of 966 outpatients with bipolar disorder gave informed consent and filled out the Personality Disorder Questionnaire, 4th edition (PDQ4) and a questionnaire on demographics and course of illness prior to Bipolar Treatment Outcome Network entry at average age 41 years. Patients were rated at each visit for depression on the Inventory of Depressive Symptoms-Clinician version (IDS-C) and for mania on the Young Mania Rating Scale (YMRS). In a subgroup, the PDQ4 was retaken during periods of depression and euthymia.

RESULTS

Patients met criteria for most personality disorders at a much higher rate when they took the PDQ4 while depressed compared to while euthymic, and scores were significantly related to the severity of depression (IDS) and of mania (YMRS) assessed within 2 weeks of taking the PDQ. Even when euthymic, more than quarter to half of the patients met criteria for a cluster A, B or C personality disorder.

CONCLUSIONS

A wide range of personality disorders occur in bipolar patients, but are highly dependent on filling out the form while depressed compared to while euthymic. How this relates to having a personality disorder assessed using a structured clinical interview remains to be tested. However, higher PDQ4 scores are related to an earlier age of onset of bipolar disorder and other factors portending a more difficult course of bipolar disorder, and the optimal treatment of these patients remains to be illuminated.

Neuroinflammation and neurotoxicity contribute to neuroprogression in neurological and psychiatric disorders

The immune system and inflammatory processes contribute to brain-related pathologies in most, if not all, neurological and psychiatric disorders. Stress is a key factor in inducing immune system dysregulation in conjunction with genetic, epigenetic and environmental factors. Activation of the immune response can alter neurotransmission leading, among others, to serotonin deficiency, and increased production of neurotoxic substances contributing to disease progression. The concept of neuroprogression is gaining acceptance among clinicians and researches as it seeks to explain the mechanism(s) responsible for disease chronicity, recurrence and treatment resistance. Therefore, measurement of neuroinflammatory biomarkers along with assessment of neurotoxic metabolites, oxidative stress and neuroplasticity impairment, will ultimately be useful tools to predict and possibly prevent the development and progression of neuropsychiatric disorders as well as to identify the most efficacious treatments.

The New News about Lithium: An Underutilized Treatment in the United States

Lithium use for the treatment of mood disorders remains quite low, particularly in the United States compared with some European countries. Mogens Schou pioneered the study of lithium for prophylaxis of the recurrent mood disorder and encouraged its greater use. In an effort to further address the appropriate role of this drug, the multiple assets of lithium beyond its well-known antimanic effect are reviewed, and a brief summary of its side effects is outlined. It appears that lithium has positive effects in depression and suicide prevention, cognition, and reducing the incidence of dementia. It increases the length of telomeres and has positive effects in prevention of some medical illnesses. Lithium side-effect burden, especially its association with end-stage renal disease, may be less than many have surmised. New data indicate the importance of long-term prophylaxis after a first manic episode to lessen episode recurrence, allow cognition to recover to normal, and prevent various aspects of illness progression. After a first manic episode, 1 year of randomized treatment with lithium was superior to that of quetiapine, suggesting the importance of having lithium in the treatment regimen. Given the highly recurrent and progressive course of bipolar disorder sometimes even in the face of conventional treatment, the role and enhanced use of lithium deserves reconsideration.

Episode accumulation associated with hastened recurrence and delayed recovery in bipolar disorder

AIMS

Assess episode accumulation (≥ 10 prior mood episodes) associations with demographic/baseline clinical characteristics and mood episode recurrence/recovery in bipolar disorder (BD).

METHODS

Stanford BD Clinic outpatients enrolled during 2000-2011 were assessed with Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation. Among recovered and syndromal mood episode patients, we assessed episode accumulation associations with demographic/baseline clinical characteristics and with recurrence/recovery (by Kaplan-Meier survival analyses, with mediators assessed with Cox Proportional Hazard Ratio (HR) analyses).

RESULTS

Among all 450 BD outpatients, almost twice as many had versus lacked episode accumulation (65.8% versus 34.2%), which was less common among 92 recovered versus 193 syndromal mood episode patients (51.1% versus 69.9%). Among recovered patients, episode accumulation was associated with 14/18 (77.7%) demographic/other baseline clinical characteristics, and hastened mood episode recurrence. Among syndromal mood episode patients, episode accumulation was associated with 13/18 (72.2%) demographic/other baseline clinical characteristics, and delayed mood episode recovery.

LIMITATIONS

American tertiary BD clinic referral sample.

CONCLUSION

Studies are needed to confirm episode accumulation is associated with hastened mood episode recurrence and delayed mood episode recovery in BD, and to further explore its' associations with hastened mood elevation recurrence and delayed recovery from depressive and mood elevation episodes, considered separately.

Cognitive Impairment In Treatment-Naïve Bipolar II and Unipolar Depression

Cognition dysfunction may reflect trait characteristics of bipolarity but cognitive effects of medications have confounded previous comparisons of cognitive function between bipolar II and unipolar depression, which are distinct clinical disorders with some overlaps. Therefore, we examined the executive function (WCST), attention, cognitive speed (TMT-A) and memory (CAVLT, WMS-Visual reproduction) of 20 treatment-naïve bipolar II patients (BPII), 35 treatment-naïve unipolar depressed (UD) patients, and 35 age/sex/education matched healthy controls. The subjects were young (aged 18–35), and had no history of psychosis or substance use, currently depressed and meeting either RDC criteria for Bipolar II Disorder or DSM-IV-TR criteria for Major Depressive Disorder. The patients were moderately depressed (MADRS) and anxious(HAM-A), on average within 3.44 years of illness onset. Sociodemographic data and IQ were similar between the groups. UD patients had significantly slower cognitive speed and cognitive flexibility (WCST perseverative error). BPII depressed patients showed relatively intact cognitive function. Verbal memory (CAVLT List A total) correlated with illness chronicity only in BPII depression, but not UD. In conclusion, young and treatment-naïve BPII depressed patients differed from unipolar depression by a relatively intact cognitive profile and a chronicity-cognitive correlation that suggested a stronger resemblance to Bipolar I Disorder than Unipolar Depression.

Altered Structural Covariance Among the Dorsolateral Prefrontal Cortex and Amygdala in Treatment-Naïve Patients With Major Depressive Disorder

Background: Impairments in cognitive and emotional processing are a characteristic of major depressive disorder (MDD), and the dorsolateral prefrontal cortex (DLPFC) and amygdala are involved in these processes. However, the structural covariance between these two areas in patients with MDD has not been examined. Whether anatomical patterns are further damaged or compensated in untreated multiple-episode MDD compared to those in first-episode MDD is unclear. Methods: Structural magnetic resonance imaging was performed in 35 treatment-naïve, currently depressed patients with MDD and 35 age-, sex-, and education-matched controls. The cortical thickness and subcortical volume were calculated using FreeSurfer software. Patients were divided into two subgroups based on the previous number of episodes. Results: Regional abnormalities in patients with MDD were primarily observed in the frontal-limbic circuits. The negative structural association between the left DLPFC and left amygdala and the positive structural association between the bilateral DLPFC observed in controls were absent in patients with MDD. The medial orbitofrontal cortex and posterior cingulate cortex were thicker in patients with multiple-episode MDD than in patients with first-episode MDD and were positively correlated with disorder duration. No structural alterations were correlated with symptom severity. Conclusions: These findings may provide structural evidence for deficits in functional networks in MDD and supports an underlying structural mechanism of dysfunction involving top-down or bottom-up processes. Morphological abnormalities in the medial orbitofrontal cortex and posterior cingulate cortex may be critical for the pathophysiological progression of multiple-episode MDD.

Staging, Neurocognition and Social Functioning in Bipolar Disorder

Introduction: Bipolar disorder (BD) is associated with significant neurocognitive and functional impairment, which may progress across stages. The 'latent stage' of BD remains understudied. This cross-sectional study assessed staging, neurocognition and social functioning among BD patients and their healthy siblings. Methods: Four groups were included: euthymic type I BD patients in the early (n = 25) and late (n = 23) stages, their healthy siblings (latent stage; n = 23) and healthy controls (n = 21). All 92 subjects underwent a comprehensive neuropsychological battery of processing speed, verbal learning/memory, visual memory, working memory, verbal fluency, executive cognition, and motor speed. Social functioning was assessed using the FAST scale. Results: Siblings' social functioning was identical to that of controls, and significantly better than both early- (p < 0.005) and late- (p < 0.001) stage patients. Although all patients were strictly euthymic, those at late stages had a significantly worse social functioning than early-stage patients (p < 0.001). Compared to controls, increasingly greater neurocognitive dysfunction was observed across stages of BD (F = 1.59; p = 0.005). Healthy siblings' performance lied between those of controls and patients, with deficits in tasks of processing speed, executive attention, verbal memory/learning, and visual memory. Both early- and late-stage patients had a more severe and widespread dysfunction than siblings, with no significant differences between them. Conclusions: Genetic vulnerability to BD-I seems to be associated with neurocognitive impairments, whereas social dysfunction would be the result of the clinical phenotype. Staging models of BD should take into account these divergent findings in the latent stage.

Longitudinal relationship between clinical course and neurocognitive impairments in bipolar disorder

BACKGROUND

The aim of this study was to estimate the relationship between clinical course and trajectory of neurocognitive functioning during a follow-up period in a sample of euthymic bipolar patients.

METHODS

Fifty-one patients with BD performed two-neurocognitive assessment separated by a period of at least 48 months. The clinical course during the follow-up period was documented by: three measures 1) number of affective episodes, 2) time spent ill, and 3) mood instability.

RESULTS

Patients were followed-up for a mean period of 73.21 months. Neurocognitive performance tended to be stable throughout the follow-up. Performance in verbal memory and executive functions at the end of study were related with the number of hypo/manic episodes and time spent with hypo/manic symptoms during the follow-up. None of the clinical measures considered were related to changes in neurocognitive performance over the follow-up period.

LIMITATIONS

The relatively small sample size limits the value of subgroup analysis. The study design does not rule out some risk of selection bias.

CONCLUSIONS

Although there may be a positive relationship between number of episodes and neurocognitive deficits in patients with bipolar disorder, successive episodes do not seem to modify the trajectory of neurocognitive functioning over time. Theoretical implications of these findings are discussed.

Sodium butyrate abolishes lipopolysaccharide-induced depression-like behaviors and hippocampal microglial activation in mice

Patients with major depressive disorder have elevated peripheral inflammation; the degree of this increase correlates with the severity of the disorder. Chronic psychological stress increases pro-inflammatory cytokines and promotes microglial activation, leading to stress vulnerability. Epigenetics, including DNA methylation and histone modification, are also related to the pathophysiology of major depressive disorder. Sodium butyrate (SB), a histone deacetylase inhibitor, exerts an antidepressant effect by altering gene expression in the hippocampus. In this study, we investigated whether lipopolysaccharide (LPS)-induced depressive-like behaviors in mice are affected by the repeated treatment with SB. Intraperitoneal injection of LPS (5 mg/kg) induced cytokines and ionized calcium-binding adaptor molecule 1(Iba1), a marker of microglial activation, in the hippocampus. It also increased the immobility time in a forced swim test, without changing locomotion. Repeated treatment with SB reduced LPS-induced alterations. These findings suggested that epigenetic regulation exist in hippocampal microglial activation, and is involved in depressive-like behaviors associated with neuro-inflammation. Further, using cDNA microarray analyses, we examined whether LPS and SB treatment affected the microglial gene profiles. Our results indicated 64 overlapping genes, between LPS-increased genes and SB-decreased genes. Among these genes, EF hand calcium binding domain 1 was a particularly distinct candidate gene. Altogether, our findings indicated that microglial activation mediated through epigenetic regulation may be involved in depressive-like behaviors. In addition, we demonstrated the effect of SB on gene information in hippocampal microglia under neuroinflammatory conditions.

Is "early intervention" in bipolar disorder what it claims to be?

BACKGROUND

The notion of early intervention is understandably appealing for conditions such as bipolar disorder (BD), a chronic life-long illness that increases risk of suicide and diminishes quality of life. It is purported that intervening early in the course of the illness with suitable interventions could substantially alter the trajectory of BD and improve outcomes. However, while there are obvious benefits to the prompt commencement of treatment, it is important to consider the gaps in our understanding regarding the aetiopathogenesis of bipolar disorder-upon which the paradigm of early intervention is predicated.

METHODS

A literature search was undertaken using recognized search engines: PubMed, PsycINFO Medline, and Scopus, along with auxiliary manual searches.

RESULTS

This review first examines how the unpredictable nature of BD creates substantial difficulties when determining an optimal therapeutic target for early intervention. Second, the challenges with identifying appropriate populations and apposite times for early intervention strategies is discussed. Finally, the risks associated with intervening early are examined, highlighting the potential harmful effects of initiating medication.

CONCLUSION

Early intervention for BD is a potentially useful strategy that warrants investigation, but until the emergence and trajectory of the illness are definitive, and a clear view of key targets is achieved, a more conservative approach to treating nascent BD and its antecedent symptoms is needed.

Elevated Choline-Containing Compound Levels in Rapid Cycling Bipolar Disorder

Previous studies have found increased levels of choline-containing compounds (ie, glycerophosphocholine plus phosphocholine (GPC+PC)) in bipolar disorder using in vivo proton magnetic resonance spectroscopy (¹H MRS), especially in bipolar I disorder (BD-I). Increased levels of GPC+PC suggest alterations in the membrane phospholipids metabolism in bipolar disorder. Rapid cycling (RC) bipolar disorder is considered as a severe course of bipolar disorder, but it is unclear whether rapid cycling bipolar disorder is linked to highly altered membrane phospholipid metabolism. The purpose of this study was to investigate whether the regional extent of elevated GPC+PC were greater in BD-I patients with rapid cycling compared to BD-I patients without rapid cycling and healthy controls. Using a multi-voxel ¹H MRS approach at 3 Tesla with high spatial resolution and absolute quantification, GPC+PC levels from the anterior cingulate cortex (ACC), caudate and putamen of 16 RC BD-I, 34 non-RC BD-I and 44 healthy controls were assessed. We found significantly elevated GPC+PC levels in ACC, putamen and caudate of RC BD-I patients compared to healthy controls (P<0.005) and in ACC compared to non-RC BD-I patients (P<0.05). These results suggest greater alteration of membrane phospholipid metabolisms in rapid cycling BD-I compared to non-rapid-cycling BD-I.

Hippocampal Gray Volumes Increase in Treatment-Resistant Depression Responding to Vagus Nerve Stimulation

BACKGROUND

Changes in hippocampal gray matter volumes are proposed to be involved in pathogenesis, course, and treatment response of major depressive disorder. Converging evidence suggests that reduced neurogenesis may occur in treatment-resistant depression (TRD). Vagus nerve stimulation (VNS) is a well-defined, long-term brain stimulation treatment for TRD. However, its in vivo positive effect on hippocampal modulation as mechanism of action has never been investigated before in clinical studies. In this study, we intended to explore hippocampal volumetric changes and clinical antidepressant responses in patients with TRD after 6 and 12 months of treatment with VNS.

METHODS

The TRD outpatients were evaluated for VNS implantation. Right and left hippocampal volumes in 6 TRD patients, who met the criteria for VNS treatment, were measured at baseline before the implantation and after 6 and 12 months. The patients were assessed using Beck Depression Inventory and Hamilton Depression Rating Scale at baseline and at follow-up visits.

RESULTS

There was a statistically significant and progressive increase in right and left hippocampal volumes during the follow up (P < 0.05). Furthermore, patients showed a significant improvement on Hamilton Depression Rating Scale and Beck Depression Inventory scores (P < 0.05).

CONCLUSIONS

Our data suggest a VNS modulatory effect on hippocampal plasticity as measured by hippocampal gray volume increase in TRD patients. These preliminary findings indicate the fundamental role of hippocampal remodeling as a marker of response to VNS in TRD.

Steeper Slope of Age-Related Changes in White Matter Microstructure and Processing Speed in Bipolar Disorder

OBJECTIVES

Bipolar disorder (BD) is associated with compromised white matter (WM) integrity and deficits in processing speed (PS). Few studies, however, have investigated age relationships with WM structure and cognition to understand possible changes in brain health over the lifespan. This investigation explored whether BD and healthy counterpart (HC) participants exhibited differential age-related associations with WM and cognition, which may be suggestive of accelerated brain and cognitive aging.

DESIGN

Cross-sectional study.

SETTING

University of California San Diego and the Veterans Administration San Diego Healthcare System.

PARTICIPANTS

33 euthymic BD and 38 HC participants.

MEASUREMENTS

Diffusion tensor imaging was acquired as a measure of WM integrity, and tract-specific fractional anisotropy (FA) was extracted utilizing the Johns Hopkins University probability atlas. PS was assessed with the Number and Letter Sequencing conditions of the Delis-Kaplan Executive Function System Trail Making Test.

RESULTS

BD participants demonstrated slower PS compared with the HC group, but no group differences were found in FA across tracts. Multiple linear regressions revealed a significant group-by-age interaction for the right uncinate fasciculus, the left hippocampal portion of the cingulum, and for PS, such that older age was associated with lower FA values and slower PS in the BD group only. The relationship between age and PS did not significantly change after accounting for uncinate FA, suggesting that the observed age associations occur independently.

CONCLUSIONS

Results provide support for future study of the accelerated aging hypothesis by identifying markers of brain health that demonstrate a differential age association in BD.

The Bipolar Illness Onset study: research protocol for the BIO cohort study

INTRODUCTION

Bipolar disorder is an often disabling mental illness with a lifetime prevalence of 1%-2%, a high risk of recurrence of manic and depressive episodes, a lifelong elevated risk of suicide and a substantial heritability. The course of illness is frequently characterised by progressive shortening of interepisode intervals with each recurrence and increasing cognitive dysfunction in a subset of individuals with this condition. Clinically, diagnostic boundaries between bipolar disorder and other psychiatric disorders such as unipolar depression are unclear although pharmacological and psychological treatment strategies differ substantially. Patients with bipolar disorder are often misdiagnosed and the mean delay between onset and diagnosis is 5-10 years. Although the risk of relapse of depression and mania is high it is for most patients impossible to predict and consequently prevent upcoming episodes in an individual tailored way. The identification of objective biomarkers can both inform bipolar disorder diagnosis and provide biological targets for the development of new and personalised treatments. Accurate diagnosis of bipolar disorder in its early stages could help prevent the long-term detrimental effects of the illness.The present Bipolar Illness Onset study aims to identify (1) a composite blood-based biomarker, (2) a composite electronic smartphone-based biomarker and (3) a neurocognitive and neuroimaging-based signature for bipolar disorder.

METHODS AND ANALYSIS

The study will include 300 patients with newly diagnosed/first-episode bipolar disorder, 200 of their healthy siblings or offspring and 100 healthy individuals without a family history of affective disorder. All participants will be followed longitudinally with repeated blood samples and other biological tissues, self-monitored and automatically generated smartphone data, neuropsychological tests and a subset of the cohort with neuroimaging during a 5 to 10-year study period.

ETHICS AND DISSEMINATION

The study has been approved by the Local Ethical Committee (H-7-2014-007) and the data agency, Capital Region of Copenhagen (RHP-2015-023), and the findings will be widely disseminated at international conferences and meetings including conferences for the International Society for Bipolar Disorders and the World Federation of Societies for Biological Psychiatry and in scientific peer-reviewed papers.

TRIAL REGISTRATION NUMBER

NCT02888262.

Cell therapy in the treatment of bipolar mania in an animal model: a proof of concept study

Abstract Introduction The rationale of mesenchymal stem cells (MSCs) as a novel therapeutic approach in certain neurodegenerative diseases is based on their ability to promote neurogenesis. Hippocampal atrophy has been related to bipolar disorder (BD) in preclinical, imaging and postmortem studies. Therefore, the development of new strategies to stimulate the neurogenesis process in BD is crucial. Objectives To investigate the behavioral and neurochemical changes induced by transplantation of MSCs in a model of mania-like behavior induced by lisdexamfetamine dimesylate (LDX). Methods Wistar rats (n=65) received one oral daily dose of LDX (10 mg/kg) or saline for 14 days. On the 8th day of treatment, the animals additionally received intrahippocampal saline or MSC (1 µL containing 25,000 cells) or lithium (47.5 mg/kg) as an internal experimental control. Two hours after the last administration, behavioral and neurochemical analyses were performed. Results LDX-treated rats had increased locomotor activity compared to saline-saline rats (p=0.004), and lithium reversed LDX-related hyperactive behavior (p<0.001). In contrast, the administration of MSCs did not change hyperlocomotion, indicating no effects of this treatment on LDX-treated rats (p=0.979). We did not find differences between groups in BDNF levels (p>0.05) in the hippocampus of rats. Conclusion Even though these results suggest that a single intrahippocampal injection of MSCs was not helpful to treat hyperactivity induced by LDX and neither influenced BDNF secretion, we cannot rule out the possible therapeutic effects of MSCs. Further research is required to determine direct effects of LDX on brain structures as well as in other pathophysiological targets related to BD.