A comparison of life events in patients with unipolar disorder or bipolar disorder and controls

Association between lifetime and recent stressful life events and the early course and psychopathology in patients with newly diagnosed bipolar disorder, first-degree unaffected relatives and healthy controls: Cross-sectional results from a prospective study

OBJECTIVE

There is an accumulation of stressful life events prior to the first mood episode, but the impact of previous severe life events on psychopathology in patients with bipolar disorder (BD) is not well studied. We aimed to examine the number of recent and lifetime life events in patients with newly diagnosed BD, their unaffected relatives (UR), and healthy controls (HC) as well as the impact of severe lifetime life events on the early course of BD.

METHODS

We compared the number of recent and lifetime life events in 398 patients with newly diagnosed BD, 109 UR, and 214 HC. We subsequently dichotomized the patients with BD by >2 lifetime life events to investigate the associations of severe lifetime life events with clinical characteristics and affective symptoms.

RESULTS

Patients with newly diagnosed BD reported significantly more life events in the last 12 months and lifetime before compared with UR and HC. Patients who reported >2 lifetime life events (n = 160) compared with patients with 0-2 life events (n = 238) had a significantly longer diagnostic delay (9.5 years ± 8.2 vs. 6.2 years ± 6.9), presented with more anxiety and depressive symptoms and had at least one previous suicide attempt (30.6% vs. 15.6%) and one previous admission (51.3% vs. 36.6%).

CONCLUSION

The experience of severe lifetime life events seems to impact the early course in BD in terms of longer diagnostic delay, more severe psychopathology including more admissions and a more than doubled risk for previous suicide attempts.

Nonlinear dynamics of mood regulation in unaffected first-degree relatives of bipolar disorder patients

BACKGROUND

Mood regulation is a complex and poorly understood process. In this study, we aimed to analyze the underlying dynamics of mood regulation in unaffected first degree relatives of patients diagnosed with bipolar disorder using time-series analysis.

METHODS

We recruited 30 unaffected first-degree relatives of bipolar disorder patients. Participants rated their mood, anxiety and energy levels using a paper-based visual analog scale; they recorded their sleep and life events as well. Participants provided information on these variables over a three month period, twice per day. We compared their data using Box-Jenkins time series analysis with data from 30 healthy controls (HC) and 30 euthymic bipolar patients (BD) to obtain information on the autocorrelation and cross-correlation of the series, and calculated entropy for mood, anxiety and energy series.

RESULTS

We analyzed 14,980 data points: 5200 in the healthy control group; 4970 in the bipolar group and 4810 in the unaffected relatives group. There were no significant differences between groups in terms of age, sex or education levels. Using Kolmogorov-Smirnov test, we found that individual measures were normally distributed in the whole sample (D = 0.23, p > 0.1). Autocorrelation functions for mood in all groups are governed by the ARIMA (1,1,0) model, which means that current values in the series are related to one previous point only. In terms of entropy for the mood series, unaffected relatives and bipolar patients showed lower values [mean (SD) : 1.028 ± 0.679; 1.042 ± 0.680], respectively, compared to healthy controls [(1.476 ± 0.33); F (2,74) = 4.39, p < 0.01]. The same case was seen in the energy series, with lower values in the unaffected relatives and bipolar patient groups [mean (SD) : 1.644 ± 0.566; 1.511 ± 0.879], respectively, compared to healthy controls [2.230 ± 0.531; F(2, 75) = 7.89, p < 0.001].

LIMITATIONS

Low resolution for the visual analog scale.

CONCLUSIONS

Using nonlinear analyses, we found that the underlying structure of mood regulation in unaffected relatives is undistinguishable from the one found in bipolar patients. Compared to healthy controls, both bipolar patients and their unaffected relatives showed lower entropy levels, which is in keeping with a more rigid system, not as flexible to cope with the demands of a changing environment.

Differential Effects of Inflammatory and Psychosocial Stress on Mood, Hypothalamic-Pituitary-Adrenal Axis, and Inflammation in Remitted Depression

BACKGROUND/AIMS

Major depressive disorder (MDD) is highly recurrent. This may be due to increased stress sensitivity after remission. Both inflammatory and psychosocial stressors are implicated in the pathogenesis of MDD, but the additive or differential effect is unclear.

METHODS

We conducted a single-blind placebo-controlled study to investigate the effects of inflammatory stress (i.e., typhoid vaccination), psychosocial stress (i.e., Trier Social Stress Test [TSST]), or a combination of both in women (25-45 years old) with (partially) remitted recurrent MDD (n = 21) and healthy female controls (n = 18). We evaluated the effect on mood measured by the Profile of Mood States, markers of the hypothalamic-pituitary-adrenal (HPA) axis activity, and inflammatory system activation. The study was performed during 2 testing days, separated by a washout of 7-14 days. In a crossover design, subjects received one of the interventions on one day and placebo on the other.

RESULTS

A lowering of mood was seen in patients (β [95% CI] = -4.79 [-6.82 to -2.75], p < 0.001) only after vaccination, but not after the TSST or the combination; this effect was not observed in controls. Controls experienced a significantly different response on adrenocorticotropic hormone (ACTH) after vaccination, with a general rise in ACTH not observed in patients. In both groups, the TSST activated the HPA axis and suppressed the inflammatory parameters.

CONCLUSIONS

There is a differential effect of inflammatory and psychosocial stress on mood and HPA axis activation in patients with remitted recurrent MDD. This may be an interesting treatment target in MDD.

Psychological Distress Symptoms Associated With Life Events in Patients With Bipolar Disorder: A Cross-Sectional Study

Stressful life events, although less serious than traumatic experiences, affect the clinical course of patients with bipolar disorder. We previously found that bipolarity in patients with major depression is related to the severity of psychological distress symptoms associated with onset-related events. Here, we investigated whether, and to what extent, bipolar patients perceive stressful events as psychological distress symptoms, specifically, intrusion, avoidance, and hyperarousal. Further, we investigated the relationship between the clinical features and the severity of psychological distress symptoms associated with stressful life events, according to mood states. We recruited 79 bipolar patients (depression group, n = 32; mania, n = 22; euthymia, n = 25) in this cross-sectional study. We adopted the Impact of Event Scale-Revised (IES-R) to assess the severity of psychological distress symptoms associated with past stressful events. We also evaluated the Hamilton Depression Rating Scale (HDRS) and the Young Mania Rating Scale (YMRS). The mean (standard deviation) IES-R scores of bipolar patients with a depressive episode (38.06 [16.56], p = 0.0005) and of those with a manic/hypomanic episode (44.56 [24.14], p = 0.004) were significantly higher than of those with euthymia (19.81 [12.86]). The HDRS, but not the YMRS, scores showed significant correlations with the IES-R scores, regardless of mood episodes (depression group, r = 0.42; mania, r = 0.64; euthymia, r = 0.70). This study demonstrates that bipolar patients with a manic/hypomanic or depressive episode perceive stressful life events as more severe psychological distress symptoms than do euthymic patients. Moreover, in patients with bipolar disorder, the severity of depressive symptoms, but not of manic symptoms, is positively correlated with that of the psychological distress symptoms, regardless of their mood episodes or euthymic state. Therefore, depressive symptoms may be closely related to the psychological distress symptoms associated with stressful past events in patients with bipolar disorder.

Role of stressful life events and kindling in bipolar disorder: Converging evidence from a mania-predominant illness course

Stressful life events can precipitate relapses and recurrences in bipolar disorder. Kindling in bipolar disorder has been linked to maladaptive psychological reactivity to minor stressful life events. Systematic studies on life events and kindling are rare in bipolar disorder with a manic predominant polarity. One hundred and forty-nine remitted patients with bipolar I disorder were recruited. The National Institute of Mental Health-Life Chart Methodology was used to depict the illness course retrospectively, and the Presumptive Stressful Life Events Scale-Lifetime version was used to record the stressful life events. The role of stressful life events and the probability of kindling were assessed using appropriate statistics. There was a mania-predominant course of bipolar disorder in the sample with 55.7% (n = 83) having only recurrent mania. Family conflict and altered sleep patterns were the commonly reported stressful life events. When controlled for the severity of the stressor, the stressful life events were often associated with the initial episodes rather than the latter ones. Kindling may occur in bipolar disorder with mania as the predominant polarity. However, retrospective recall bias and hospital-based sampling limit generalizability of such observations.

Plasma copeptin and metabolic dysfunction in individuals with bipolar disorder

AIM

This study aimed to compare plasma copeptin levels, the c-terminal of provasopressin, between individuals with bipolar disorder (BD) and healthy controls and to assess the relation between copeptin and metabolic parameters.

METHODS

We measured plasma levels of copeptin in individuals with BD (n = 55) and healthy controls (n = 21). Information related to psychiatric/medical history, as well as to metabolic comorbidities and laboratorial parameters was also captured. Insulin resistance and β-cell function in basal state were calculated from fasting plasma glucose and C-peptide using the HOMA2 calculator. Impaired glucose metabolism was defined as pre-diabetes or type 2 diabetes mellitus. Copeptin, adiponectin, and leptin plasma levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Plasma copeptin levels were lower in individuals with BD, relative to healthy controls (P < 0.001). There were significant interactions between BD and plasma copeptin on β-cell function (rate ratio [RR] = 1.048; P = 0.030) and on leptin levels (RR = 1.087; P = 0.012), indicating that there was a positive correlation between these markers in the BD group, but a negative one in healthy controls. Finally, in individuals with BD only, the association between β-cell function, body mass index (RR = 1.007; P < 0.001), and insulin resistance (RR = 1.001; P = 0.037) was moderated by copeptin levels.

CONCLUSION

Copeptin levels were lower in individuals with BD than in healthy controls. There were differential associations between copeptin and metabolic parameters within the BD and healthy control subgroups, suggesting an association between abnormal copeptin and metabolic dysregulation only in the BD population.

Physical Activity Modulates Common Neuroplasticity Substrates in Major Depressive and Bipolar Disorder

Mood disorders (MDs) are chronic, recurrent mental diseases that affect millions of individuals worldwide. Although the biogenic amine model has provided some clinical utility, a need remains to better understand the interrelated mechanisms that contribute to neuroplasticity deficits in MDs and the means by which various therapeutics mitigate them. Of those therapeutics being investigated, physical activity (PA) has shown clear and consistent promise. Accordingly, the aims of this review are to (1) explicate key modulators, processes, and interactions that impinge upon multiple susceptibility points to effectuate neuroplasticity deficits in MDs; (2) explore the putative mechanisms by which PA mitigates these features; (3) review protocols used to induce the positive effects of PA in MDs; and (4) highlight implications for clinicians and researchers.

Does stress play a significant role in bipolar disorder? A meta-analysis

BACKGROUND

There is evidence that stressful life events (LE) play a crucial role in the etiology of bipolar affective disorder (BD). However, primary studies, as well as narrative reviews, have provided mixed results. The present meta-analysis combined and analyzed previous data in order to address these inconsistencies.

METHOD

Forty-two studies published in 53 records were identified by systematically searching MEDLINE, PsychINFO, and PSYCHINDEX using the terms "bipolar disorder" OR "manic-depressive" OR "bipolar affective disorder" OR "mania" AND "stress" OR "life event" OR "daily hassles" OR "goal attainment". Then, meta-analyses were conducted.

RESULTS

Individuals diagnosed with BD reported more LE before relapse when compared to euthymic phases. They also experienced more LE relative to healthy individuals and to physically ill patients. No significant difference in the number of LE was found when BD was compared to unipolar depression and schizophrenia.

LIMITATIONS

When interpreting the present meta-analytic findings one should keep in mind that most included studies were retrospective and often did not specify relevant information, e.g., if the LE were chronic or acute or if the individuals were diagnosed with BD I or II. We could not entirely rule out a publication bias.

CONCLUSION

The present meta-analyses found that individuals with BD were sensitive to LE, which corroborates recent theoretical models and psychosocial treatment approaches of BD. Childbirth, as a specific LE, affected individuals with BD more than individuals with unipolar depression. Future studies that investigate specific LE are warranted.

Relationship between childhood adversity and bipolar affective disorder: systematic review and meta-analysis

BACKGROUND

The relationship between childhood adversity and bipolar affective disorder remains unclear.

AIMS

To understand the size and significance of this effect through a statistical synthesis of reported research.

METHOD

Search terms relating to childhood adversity and bipolar disorder were entered into Medline, EMBASE, PsycINFO and Web of Science. Eligible studies included a sample diagnosed with bipolar disorder, a comparison sample and a quantitative measure of childhood adversity.

RESULTS

In 19 eligible studies childhood adversity was 2.63 times (95% CI 2.00-3.47) more likely to have occurred in bipolar disorder compared with non-clinical controls. The effect of emotional abuse was particularly robust (OR = 4.04, 95% CI 3.12-5.22), but rates of adversity were similar to those in psychiatric controls.

CONCLUSIONS

Childhood adversity is associated with bipolar disorder, which has implications for the treatment of this clinical group. Further prospective research could clarify temporal causality and explanatory mechanisms.

Nonlinear dynamics of mood regulation in bipolar disorder

OBJECTIVES

We sought to study the underlying dynamic processes involved in mood regulation in subjects with bipolar disorder and healthy control subjects using time-series analysis and to then analyze the relation between anxiety and mood using cross-correlation techniques.

METHODS

We recruited 30 healthy controls and 30 euthymic patients with bipolar disorder. Participants rated their mood, anxiety, and energy levels using a paper-based visual analog scale; and they also recorded their sleep and any life events. Information on these variables was provided over a three-month period on a daily basis, twice per day. We analyzed the data using Box-Jenkins time series analysis to obtain information on the autocorrelation of the series (for mood) and cross-correlation (mood and anxiety series).

RESULTS

Throughout the study, we analyzed 10,170 data points. Self-ratings for mood, anxiety, and energy were normally distributed in both groups. Autocorrelation functions for mood in both groups were governed by the autoregressive integrated moving average (ARIMA) (1,1,0) model, which means that current values in the series were related to one previous point only. We also found a negative cross-correlation between mood and anxiety.

CONCLUSIONS

Mood can be considered a memory stochastic process; it is a flexible, dynamic process that has a 'short memory' both in healthy controls and euthymic patients with bipolar disorder. This process may be quite different in untreated patients or in those acutely ill. Our results suggest that nonlinear measures can be applied to the study of mood disorders.

Is there a "metabolic-mood syndrome"? A review of the relationship between obesity and mood disorders

Obesity and mood disorders are highly prevalent and co-morbid. Epidemiological studies have highlighted the public health relevance of this association, insofar as both conditions and its co-occurrence are associated with a staggering illness-associated burden. Accumulating evidence indicates that obesity and mood disorders are intrinsically linked and share a series of clinical, neurobiological, genetic and environmental factors. The relationship of these conditions has been described as convergent and bidirectional; and some authors have attempted to describe a specific subtype of mood disorders characterized by a higher incidence of obesity and metabolic problems. However, the nature of this association remains poorly understood. There are significant inconsistencies in the studies evaluating metabolic and mood disorders; and, as a result, several questions persist about the validity and the generalizability of the findings. An important limitation in this area of research is the noteworthy phenotypic and pathophysiological heterogeneity of metabolic and mood disorders. Although clinically useful, categorical classifications in both conditions have limited heuristic value and its use hinders a more comprehensive understanding of the association between metabolic and mood disorders. A recent trend in psychiatry is to move toward a domain specific approach, wherein psychopathology constructs are agnostic to DSM-defined diagnostic categories and, instead, there is an effort to categorize domains based on pathogenic substrates, as proposed by the National Institute of Mental Health (NIMH) Research Domain Criteria Project (RDoC). Moreover, the substrates subserving psychopathology seems to be unspecific and extend into other medical illnesses that share in common brain consequences, which includes metabolic disorders. Overall, accumulating evidence indicates that there is a consistent association of multiple abnormalities in neuropsychological constructs, as well as correspondent brain abnormalities, with broad-based metabolic dysfunction, suggesting, therefore, that the existence of a "metabolic-mood syndrome" is possible. Nonetheless, empirical evidence is necessary to support and develop this concept. Future research should focus on dimensional constructs and employ integrative, multidisciplinary and multimodal approaches.

Eventos de vida estressores e episódios de humor: uma amostra comunitária

Transtornos de humor são consequentes de uma interação entre fatores biológicos e ambientais. O objetivo deste estudo foi identificar associações entre eventos vitais estressores e transtornos de humor em uma amostra comunitária de jovens do Sul do Brasil. Trata-se de estudo transversal de base populacional com jovens de 18 a 24 anos. A seleção da amostra foi realizada por conglomerados. Os episódios de alteração do humor foram avaliados através da Mini International Neuropsychiatric Interview , enquanto os eventos vitais estressores foram mensurados através da escala de reajustamento social de Holmes e Rahe. A amostra foi de 1172 jovens. A proporção de eventos vitais estressores no último ano, em cada categoria, no total da amostra, foi de: 53,8% trabalho, 42,4% perda de suporte social, 63,8% família, 50,9% mudanças ambientais, 61,1% dificuldades pessoais e 38,7% finanças. Houve associação significativa entre eventos vitais estressores e episódios de alteração de humor. Foi verificada maior ocorrência de eventos vitais estressores entre os jovens em episódio misto, quando comparados aos jovens em episódio depressivo, (hipo) maníaco e controles. Esses achados sugerem uma interação psicossocial entre eventos vitais estressores e os episódios de alteração de humor.

Childhood trauma in bipolar disorder

OBJECTIVE

There has been little investigation of early trauma in bipolar disorder despite evidence that stress impacts on the course of this illness. We aimed to compare the rates of childhood trauma in adults with bipolar disorder to a healthy control group, and to investigate the impact of childhood trauma on the clinical course of bipolar disorder.

METHODS

Retrospective assessment of childhood trauma was conducted using the Childhood Trauma Questionnaire (CTQ) in 60 outpatients with bipolar disorder being treated for a depressive episode and 55 control participants across two centres in north-east England and New Zealand.

RESULTS

Significantly higher rates of childhood trauma were observed in patients with bipolar I and bipolar II disorder compared to controls. Logistic regression, controlling for age and sex, identified emotional neglect to be the only significant CTQ subscale associated with a diagnosis of bipolar disorder. Childhood history of sexual abuse was not a significant predictor. Associations with clinical severity or course were less clear.

CONCLUSIONS

Childhood emotional neglect appears to be significantly associated with bipolar disorder. Limitations include the relatively small sample size, which potentially increases the risk of type II errors. Replication of this study is required, with further investigation into the neurobiological consequences of childhood trauma, particularly emotional neglect.

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

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

Long-lasting marked inhibition of periaqueductal gray-evoked defensive behaviors in inescapably-shocked rats

Clinical evidence suggests that depression and trauma predispose the subject to panic. Accordingly, here we examined the late effects of uncontrollable stress, a presumptive model of depression and/or traumatic disorder, on panic-like behaviors evoked by electrical stimulation of the dorsal periaqueductal gray (DPAG). Changes in anxiety and depression were also assessed in the elevated plus-maze (EPM) and forced-swimming test (FST), respectively. Rats with electrodes in the DPAG were subjected to a 7-day shuttle-box one-way escape yoked training with foot-shocks either escapable (ES) or inescapable (IS). The day after the end of one-way escape training, rats were trained in a two-way escape novel task (test-session) to ascertain the effectiveness of uncontrollable stress. DPAG stimulations were carried out in an open field, both before the escape training and 2 and 7 days after it, and EPM and FST were performed on the 8th and 10th days afterwards, respectively. Controls were either trained with fictive shocks (FS) or subjected to intracranial stimulations only. Although the ES rats performed significantly better than the IS group in the two-way escape task, groups did not differ with respect to either the anxiety or depression scores. Unexpectedly, however, IS rats showed a marked attenuation of DPAG-evoked freezing and flight behaviors relative to both the ES and FS groups, 2 and 7 days after one-way escape training. The conjoint inhibition of passive (freezing) and active (flight) defensive behaviors suggests that IS inhibits a DPAG in-built motivational system that may be implicated in depressed patients' difficulties in coping with daily-life stress.

Tradução e adaptação semântica para versão em português do Stressful Life Events Schedule (SLES)

O Stressful Life Events Schedule (SLES) é um instrumento que visa investigar a presença e o impacto de eventos de vida estressantes (EVE) ocorridos nos últimos 12 meses. O objetivo deste trabalho é traduzir e adaptar por equivalência semântica os itens da escala para a língua portuguesa. Seis etapas foram realizadas: (1) Tradução; (2) Retrotradução; (3) Revisão técnica e adaptação semântica; (4) Avaliação e validação do conteúdo e do significado geral considerando o contexto da população; (5) Realização de uma medida de confiabilidade em relação ao construto dependência/independência dos EVE; e (6) Produção da versão final do instrumento. O tempo verbal se manteve na maioria dos itens da escala. Algumas alterações foram necessárias como um acréscimo da variação de alguns termos. A versão adaptada demonstrou ser de fácil aplicação, não tendo sido avaliada como extensa e contemplando um número considerável de EVE.

The role of loss and danger events in symptom exacerbation in bipolar disorder

Research concerned with the association between stressful life events [SLEs] and bipolar disorder [BD] is inconsistent. Drawing on the unipolar depression literature, specific classifications of events (in particular, humiliation and loss events) seem to be especially important, while for anxiety disorders loss and danger events have been found to be pertinent. However, little or nothing is known about the relationship between such events and BD. The aim of the present investigation is to examine the association between danger and loss events and symptom exacerbation in BD. A total of 96 BD participants were interviewed using the Life Events and Difficulties Schedule [LEDS] at two time points: baseline and 4 month follow-up. Self-report and observer-rated symptom measures were administered at both interviews. The Beck Depression Inventory-Second Edition and the Montgomery Asberg Depression Rating Scale were used to measure depressive symptoms. The Self-Report Mania Inventory and Clinician-Administered Rating Scale for Mania were used to rate manic symptoms. Independent severe events, independent loss events and independent danger events were found to be significantly associated with worsening of depressive symptoms over an 8-month period. No significant associations were observed for manic symptoms. Specific relationships with different types of SLEs may explain previous discrepant findings concerning the relationship between SLEs and BD.

Life-event specificity: bipolar disorder compared with unipolar depression

BACKGROUND

Little is known about the impact of different types of stressful events (for example divorce v. bereavement) on unipolar depression compared with bipolar disorder. Inconsistencies exist concerning the association between independent events (beyond an individual's control, such as bereavement) and bipolar disorder.

AIMS

To examine the role of specific, independent and dependent events in mood disorders.

METHOD

Life-event information was collected from 512 people with bipolar disorder, 1448 people with unipolar depression and over 600 controls.

RESULTS

Various events were associated with unipolar depression and bipolar disorder, but some event specificity was detected. For example, financial crisis was more strongly related to bipolar disorder rather than unipolar depression. Independent events were only related to unipolar depression and not bipolar disorder.

CONCLUSIONS

The events that were linked to bipolar disorder and unipolar depression were similar. Independent events were not associated with bipolar episodes, suggesting that life stress may be a consequence of, rather than a trigger for, bipolar episodes.

A theoretical framework informing research about the role of stress in the pathophysiology of bipolar disorder

BACKGROUND

The staggering illness burden associated with Bipolar Disorder (BD) invites the need for primary prevention strategies. Before preventative strategies can be considered in individuals during a pre-symptomatic period (i.e., at risk), unraveling the mechanistic steps wherein external stress is transduced and interacts with genetic vulnerability in the early stages of BD will be a critical conceptual necessity.

METHODS

Herein we comprehensively review extant studies reporting on stress and bipolar disorder. The overarching aim is to propose a conceptual framework to inform research about the role of stress in the pathophysiology of BD. Computerized databases i.e. PubMed, PsychInfo, Cochrane Library and Scielo were searched using the following terms: "bipolar disorder" cross-referenced with "stress", "general reaction to stress", "resilience", "resistance", "recovery" "stress-diathesis", "allostasis", and "hormesis".

RESULTS

Data from literature indicate the existence of some theoretical models to understand the influence of stress in the pathophysiology of BD, including classical stress-diathesis model and new models such as allostasis and hormesis. In addition, molecular mechanisms involved in stress adaptation (resistance, resilience and recovery) can also be translated in research strategies to investigate the impact of stress in the pathophysiology of BD.

LIMITATIONS

Most studies are retrospective and/or cross sectional, do not consider the period of development, assess brain function with only one or few methodologies, and use animal models which are not always similar to human phenotypes.

CONCLUSION

The interaction between stress and brain development is dynamic and complex. In this article we proposed a theoretical model for investigation about the role of stress in the pathophysiology of BD, based on the different kinds of stress adaptation response and their putative neurobiological underpinnings.

The "selfish brain" hypothesis for metabolic abnormalities in bipolar disorder and schizophrenia

Metabolic abnormalities are frequent in patients with schizophrenia and bipolar disorder (BD), leading to a high prevalence of diabetes and metabolic syndrome in this population. Moreover, mortality rates among patients are higher than in the general population, especially due to cardiovascular diseases. Several neurobiological systems involved in energy metabolism have been shown to be altered in both illnesses; however, the cause of metabolic abnormalities and how they relate to schizophrenia and BD pathophysiology are still largely unknown. The "selfish brain" theory is a recent paradigm postulating that, in order to maintain its own energy supply stable, the brain modulates energy metabolism in the periphery by regulation of both allocation and intake of nutrients. We hypothesize that the metabolic alterations observed in these disorders are a result of an inefficient regulation of the brain energy supply and its compensatory mechanisms. The selfish brain theory can also expand our understanding of stress adaptation and neuroprogression in schizophrenia and BD, and, overall, can have important clinical implications for both illnesses.

The precipitants of manic/hypomanic episodes in the context of bipolar disorder: a review

BACKGROUND

Mania/hypomania is the hallmark feature of bipolar disorder. This paper aims to review the current evidence in relation to factors hypothesised to precipitate bipolar mania/hypomania, and suggest areas for future research.

METHODS

A selective review of original and review papers was conducted. The electronic databases 'PsycINFO' and 'PubMed' were searched using the following search strings: "bipolar disorder" or "mania" or "hypomania" or "manic-depression" with "triggers" or "precipitants" or "precedents" or "predictors".

RESULTS

There is evidence that goal attainment events, antidepressant medication, disrupted circadian rhythms, spring/summer seasonal conditions, and more tentatively, stressful life events and high emotional expression, may precipitate bipolar mania/hypomania in susceptible individuals. Evidence from case reports and clinical observations are also reported.

DISCUSSION

The pathways to bipolar mania/hypomania may be many and varied, and many of these pathways may be outside the awareness of individuals with bipolar disorder. Greater awareness of the broad number of precipitating factors is needed to inform self-management and psycho-educational programs to build resilience to further episodes. Future research is needed to explore what other factors may precipitate bipolar mania/hypomania, and to determine why some factors may precipitate mania/hypomania in some individuals with bipolar I or II disorder but not in others.

Functional outcome in bipolar disorder: the big picture

Previous research on functional outcome in bipolar disorder (BD) has uncovered various factors that exacerbate psychosocial disability over the course of illness, including genetics, illness severity, stress, anxiety, and cognitive impairment. This paper presents an integrated view of these findings that accounts for the precipitous decline in psychosocial functioning after illness onset. The proposed model highlights a number of reciprocal pathways among previously studied factors that trap people in a powerful cycle of ailing forces. The paper discusses implications to patient care as well as the larger social changes required for shifting the functional trajectory of people with BD from psychosocial decline to growth.

Switching to hypomania and mania: differential neurochemical, neuropsychological, and pharmacologic triggers and their mechanisms

Current data suggest that monoamines, acetylcholine, amino acids, cortisol, thyroid hormones, and melatonin may be involved in the pathophysiology of bipolar disorder (BPD). Any neuropsychological or pharmacologic factor causing a disturbance in these neurochemicals may trigger manic/hypomanic switching. Antidepressants, stimulants, anticholinergics, steroids, and thyroid hormone have been reported to cause treatment-emergent mania (TEM) in BPD, but only recently have the traditional antidepressants been systematically studied. Paroxetine, 20 mg/d, monotherapy in treatment of acute, relatively "pure" bipolar I and II depression, and fluoxetine monotherapy in bipolar II depression conferred a similar risk as placebo for TEM. Paroxetine or bupropion adjunctive therapy to mood stabilizer(s) had a similar risk as placebo for treatment of TEM in real world patients with bipolar depression during continuation treatment. Venlafaxine was shown to have an increased risk of TEM compared with bupropion and sertraline. The evolving literature continues to support the role of mood stabilizers in preventing future mood episodes of BPD.