The role of environmental exposures as risk factors for bipolar disorder: A systematic review of longitudinal studies

Investigating 7,8-Dihydroxyflavone to combat maternal immune activation effects on offspring gene expression and behaviour

Infection during pregnancy is a substantial risk factor for the unborn child to develop autism or schizophrenia later in life, and is thought to be driven by maternal immune activation (MIA). MIA can be modelled by exposing pregnant mice to Polyinosinic: polycytidylic acid (Poly-I:C), a viral mimetic that induces an immune response and recapitulates in the offspring many neurochemical features of ASD and schizophrenia, including altered BDNF-TrkB signalling and disruptions to excitatory/inhibitory balance. Therefore, we hypothesised that a BDNF mimetic, 7,8-Dihydroxyflavone (7,8-DHF), administered prophylactically to the dam may prevent the neurobehavioural sequelae of disruptions induced by MIA. Dams were treated with 7,8-DHF in the drinking water (0.08 mg/ML) from gestational day (GD) 9-20 and were exposed to Poly-I:C at GD17 (20 mg/kg, i.p.). Foetal brains were collected 6 h post Poly-I:C exposure for RT-qPCR analysis of BDNF, cytokine, GABAergic and glutamatergic gene targets. A second adult cohort were tested in a battery of behavioural tests relevant to schizophrenia and the prefrontal cortex and ventral hippocampus dissected for RT-qPCR analysis. Foetal brains exposed to Poly-I:C showed increased IL-6, but reduced expression of Ntrk2 and multiple GABAergic and glutamatergic markers. Anxiety-like behaviour was observed in adult offspring prenatally exposed to poly-I:C, which was accompanied by altered expression of Gria2 in the prefrontal cortex and Gria4 in the ventral hippocampus. While 7-8 DHF normalised the expression of some glutamatergic (Grm5) and GABAergic (Gabra1) genes in Poly-I:C exposed offspring, it also led to substantial alterations in offspring not exposed to Poly-I:C. Furthermore, mice exposed to 7,8-DHF prenatally showed increased pre-pulse inhibition and reduced working memory in adulthood. These data advance understanding of how 7,8-DHF and MIA prenatal exposure impacts genes critical to excitatory/inhibitory pathways and related behaviour.

Factors that influence participation in physical activity for people with bipolar disorder: a synthesis of qualitative evidence

BACKGROUND

Mental health problems contribute significantly to the overall disease burden worldwide and are major causes of disability, suicide, and ischaemic heart disease. People with bipolar disorder report lower levels of physical activity than the general population, and are at greater risk of chronic health conditions including cardiovascular disease and obesity. These contribute to poor health outcomes. Physical activity has the potential to improve quality of life and physical and mental well-being.

OBJECTIVES

To identify the factors that influence participation in physical activity for people diagnosed with bipolar disorder from the perspectives of service users, carers, service providers, and practitioners to help inform the design and implementation of interventions that promote physical activity.

SEARCH METHODS

We searched MEDLINE, PsycINFO, and eight other databases to March 2021. We also contacted experts in the field, searched the grey literature, and carried out reference checking and citation searching to identify additional studies. There were no language restrictions.

SELECTION CRITERIA

We included qualitative studies and mixed-methods studies with an identifiable qualitative component. We included studies that focused on the experiences and attitudes of service users, carers, service providers, and healthcare professionals towards physical activity for bipolar disorder.

DATA COLLECTION AND ANALYSIS

We extracted data using a data extraction form designed for this review. We assessed methodological limitations using a list of predefined questions. We used the "best fit" framework synthesis based on a revised version of the Health Belief Model to analyse and present the evidence. We assessed methodological limitations using the CASP Qualitative Checklist. We used the GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) guidance to assess our confidence in each finding. We examined each finding to identify factors to inform the practice of health and care professionals and the design and development of physical activity interventions for people with bipolar disorder.

MAIN RESULTS

We included 12 studies involving a total of 592 participants (422 participants who contributed qualitative data to an online survey, 170 participants in qualitative research studies). Most studies explored the views and experiences of physical activity of people with experience of bipolar disorder. A number of studies also reported on personal experiences of physical activity components of lifestyle interventions. One study included views from family carers and clinicians. The majority of studies were from high-income countries, with only one study conducted in a middle-income country. Most participants were described as stable and had been living with a diagnosis of bipolar disorder for a number of years. We downgraded our confidence in several of the findings from high confidence to moderate or low confidence, as some findings were based on only small amounts of data, and the findings were based on studies from only a few countries, questioning the relevance of these findings to other settings. We also had very few perspectives of family members, other carers, or health professionals supporting people with bipolar disorder. The studies did not include any findings from service providers about their perspectives on supporting this aspect of care. There were a number of factors that limited people's ability to undertake physical activity. Shame and stigma about one's physical appearance and mental health diagnosis were discussed. Some people felt their sporting skills/competencies had been lost when they left school. Those who had been able to maintain exercise through the transition into adulthood appeared to be more likely to include physical activity in their regular routine. Physical health limits and comorbid health conditions limited activity. This included bipolar medication, being overweight, smoking, alcohol use, poor diet and sleep, and these barriers were linked to negative coping skills. Practical problems included affordability, accessibility, transport links, and the weather. Workplace or health schemes that offered discounts were viewed positively. The lack of opportunity for exercise within inpatient mental health settings was a problem. Facilitating factors included being psychologically stable and ready to adopt new lifestyle behaviours. There were positive benefits of being active outdoors and connecting with nature. Achieving balance, rhythm, and routine helped to support mood management. Fitting physical activity into a regular routine despite fluctuating mood or motivation appeared to be beneficial if practised at the right intensity and pace. Over- or under-exercising could be counterproductive and accelerate depressive or manic moods. Physical activity also helped to provide a structure to people's daily routines and could lead to other positive lifestyle benefits. Monitoring physical or other activities could be an effective way to identify potential triggers or early warning signs. Technology was helpful for some. People who had researched bipolar disorder and had developed a better understanding of the condition showed greater confidence in managing their care or providing care to others. Social support from friends/family or health professionals was an enabling factor, as was finding the right type of exercise, which for many people was walking. Other benefits included making social connections, weight loss, improved quality of life, and better mood regulation. Few people had been told of the benefits of physical activity. Better education and training of health professionals could support a more holistic approach to physical and mental well-being. Involving mental health professionals in the multidisciplinary delivery of physical activity interventions could be beneficial and improve care. Clear guidelines could help people to initiate and incorporate lifestyle changes.

AUTHORS' CONCLUSIONS

There is very little research focusing on factors that influence participation in physical activity in bipolar disorder. The studies we identified suggest that men and women with bipolar disorder face a range of obstacles and challenges to being active. The evidence also suggests that there are effective ways to promote managed physical activity. The research highlighted the important role that health and care settings, and professionals, can play in assessing individuals' physical health needs and how healthy lifestyles may be promoted. Based on these findings, we have provided a summary of key elements to consider for developing physical activity interventions for bipolar disorder.

Refugee status and the incidence of affective psychotic disorders and non-psychotic bipolar disorder: A register-based cohort study of 1.3m people in Sweden

BACKGROUND

Refugees are at increased risk of non-affective psychotic disorders, but it is unclear whether this extends to affective psychotic disorders [APD] or non-psychotic bipolar disorder [NPB].

METHODS

We conducted a nationwide cohort study in Sweden of all refugees, non-refugee migrants and the Swedish-born population, born 1 Jan 1984-31 Dec 2016. We followed participants from age 14 years until first ICD-10 diagnosis of APD or NPB. We fitted Cox proportional hazards models to estimate hazard ratios [HR] and 95 % confidence intervals [95%CI], adjusted for age, sex and family income. Models were additionally stratified by region-of-origin.

RESULTS

We followed 1.3 million people for 15.1 million person-years, including 2428 new APD cases (rate: 16.0 per 100,000 person-years; 95%CI: 15.4-16.7) and 9425 NPB cases (rate: 63.8; 95%CI: 62.6-65.1). Rates of APD were higher in refugee (HRadjusted: 2.07; 95%CI: 1.55-2.78) and non-refugee migrants (HRadjusted: 1.40; 95%CI: 1.16-1.68), but lower for NPBs for refugee (HRadjusted: 0.24; 95%CI: 0.16-0.38) and non-refugee migrants (HRadjusted: 0.34; 95%CI: 0.28-0.41), compared with the Swedish-born. APD rates were elevated for both migrant groups from Asia and sub-Saharan Africa, but not other regions. Migrant groups from all regions-of-origin experienced lower rates of NPB.

LIMITATIONS

Income may have been on the causal pathway making adjustment inappropriate.

CONCLUSIONS

Refugees experience elevated rates of APD compared with Swedish-born and non-refugee migrants, but lower rates of NPB. This specificity of excess risk warrants clinical and public health investment in appropriate psychosis care for these vulnerable populations.

Genetic causal association between varicella-zoster virus infection and psychiatric disorders: A 2-sample Mendelian randomization study

BACKGROUND

Psychiatric disorders, such as schizophrenia (SCZ), major depressive (MDD), and bipolar disorder (BD) have a profound impact on millions of individuals worldwide. The critical step toward developing effective preventive and treatment strategies lies in comprehending the causal mechanisms behind these diseases and identifying modifiable risk factors associated with them.

METHODS

In this study, we conducted a 2-sample Mendelian randomization analysis to explore the potential links between chickenpox(varicella-zoster virus infection) and three major psychiatric disorders(SCZ, MDD, BD).

RESULTS

In our MR study, among the three major psychiatric disorders, chickenpox was shown to be causally related to BD, indicating that infection with chickenpox may increase the risk of developing BD (IVW: OR = 1.064, 95% CI =1.025-1.104, P=0.001; RAPS: OR=1.066, 95% CI=1.024-1.110, P=0.002), while there was no causal relationship between SCZ and MDD. Similar estimated causal effects were observed consistently across the various MR models. The robustness of the identified causal relationship between chickenpox and BD holds true regardless of the statistical methods employed, as confirmed by extensive sensitivity analyses that address violations in model assumptions. The MR-Egger regression test failed to reveal any signs of directional pleiotropy (intercept = -0.042, standard error (SE) = 0.029, p = 0.236). Similarly, the MR-PRESSO analysis revealed no evidence of directional pleiotropy or outliers among the chickenpox-related instrumental variables (global test p = 0.653). Furthermore, a leave-one-out sensitivity analysis yielded consistent results, further underscoring the credibility and stability of the causal relationship.

CONCLUSIONS

Our findings provide compelling evidence of a causal effect of chickenpox on the risk of BD. To gain a more comprehensive understanding of this association and its underlying mechanisms, additional research is needed. Such investigations are pivotal in identifying effective interventions for promoting BD prevention.

The emerging neuroimmune hypothesis of bipolar disorder: An updated overview of neuroimmune and microglial findings

Bipolar disorder (BD) is a severe and multifactorial disease, with onset usually in young adulthood, which follows a progressive course throughout life. Replicated epidemiological studies have suggested inflammatory mechanisms and neuroimmune risk factors as primary contributors to the onset and development of BD. While not all patients display overt markers of inflammation, significant evidence suggests that aberrant immune signaling contributes to all stages of the disease and seems to be mood phase dependent, likely explaining the heterogeneity of findings observed in this population. As the brain's immune cells, microglia orchestrate the brain's immune response and play a critical role in maintaining the brain's health across the lifespan. Microglia are also highly sensitive to environmental changes and respond to physiological and pathological events by adapting their functions, structure, and molecular expression. Recently, it has been highlighted that instead of a single population of cells, microglia comprise a heterogeneous community with specialized states adjusted according to the local molecular cues and intercellular interactions. Early evidence has highlighted the contribution of microglia to BD neuropathology, notably for severe outcomes, such as suicidality. However, the roles and diversity of microglial states in this disease are still largely undermined. This review brings an updated overview of current literature on the contribution of neuroimmune risk factors for the onset and progression of BD, the most prominent neuroimmune abnormalities (including biomarker, neuroimaging, ex vivo studies) and the most recent findings of microglial involvement in BD neuropathology. Combining these different shreds of evidence, we aim to propose a unifying hypothesis for BD pathophysiology centered on neuroimmune abnormalities and microglia. Also, we highlight the urgent need to apply novel multi-system biology approaches to characterize the diversity of microglial states and functions involved in this enigmatic disorder, which can open bright perspectives for novel biomarkers and therapeutic discoveries.

Bipolar disorder and cumulative trauma: A systematic review of prevalence and illness outcomes

BACKGROUND

The experience of cumulative trauma may be common in bipolar disorder (BD). However, it is not frequently reported as most studies focus on childhood trauma without examining differences in the amount of trauma experienced. This systematic review aimed to determine the prevalence of lifetime cumulative trauma in BD as well as explore associated illness outcomes.

METHODS

A systematic review was completed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Both the prevalence and outcomes of cumulative trauma in BD were assessed. Five electronic databases were searched (Embase, MEDLINE, PsycINFO, Web of Science, and PTSD Pubs) for records from January 2010 until December 2022.

RESULTS

A total of 20 studies, with 9304 participants were included in the narrative synthesis. At least one-third of BD participants had experienced cumulative trauma, with a prevalence range from 29% to 82%. The main outcomes associated with a history of cumulative trauma were earlier age of onset, longer episode duration, more lifetime mood episodes, greater likelihood of experiencing psychotic features, and higher likelihood of past suicide attempts.

LIMITATIONS

This review has been limited by the lack of studies directly assessing cumulative trauma in BD.

CONCLUSIONS

Cumulative trauma is prevalent in BD. Preliminary evidence indicates an association with a range of adverse outcomes, emphasizing the need for clinicians to obtain a detailed trauma history and to consider these risks in the management of the disorder. Future studies should report on the prevalence of cumulative trauma, particularly in adulthood as this area remains unexplored.

Time on our side: An exploratory investigation of the relationship between psychiatric disorder and time attitudes

Time attitudes indicate how individuals feel about the past, present, and future. A growing body of research has demonstrated that scores on the Adolescent and Adult Time Inventory-Time Attitudes Scale relate meaningfully to a variety of measures of well-being and psychiatric symptomatology. To date, no study has examined how (if at all) Time Attitudes scores relate to psychiatric disorder. The present study used an existing clinical cohort (N = 68) and assessed the associations among time attitudes, lifetime disorder, and a retrospective measure of childhood trauma. Preliminary analyses revealed that mean scores of the six time attitudes in the present study did not differ substantially from scores reported in a recent meta-analysis. Correlations between time attitude scores and retrospective trauma scores were particularly large for past negative and past positive. Individuals with no past or current disorder reported substantially higher positive attitudes and substantially lower negative attitudes than those without a disorder across all three time periods with interpretable effect sizes. Finally, past negative time attitudes scores were significantly associated with lifetime mood or anxiety disorder, prior to adjustment for scores on self-reported childhood trauma. These results suggest that time attitudes could be a variable of consequence beyond feelings of general well-being and beyond psychiatric symptoms. More studies with larger sample sizes are required in order to examine the relationship between time attitudes and psychiatric disorder.

The relationship between childhood interpersonal and non-interpersonal trauma and autobiographical memory: a systematic review

Childhood trauma can have negative effects on several domains of mental functioning, including Autobiographical Memory (AM). Conflicting results emerge in the scientific literature regarding the effects of childhood trauma on AM. In this review, we explored the relationship between the childhood trauma and AM, classifying childhood trauma as interpersonal, non-interpersonal and overall (interpersonal and non-interpersonal). We carried out a systematic literature review, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA statement). From searching the PubMed, Scopus, and Web of Science databases, we identified 48 studies conducted from 2014 to 2023, which were included when they: (a) were written in English, (b) investigated the relationship between AM and childhood trauma, (c) included a sample of children, adolescents, or adults who had experienced childhood interpersonal and/or non-interpersonal trauma. Of the 48 eligible studies, 29 referred to trauma of an interpersonal nature, 12 to trauma of a non-interpersonal nature, and 7 to overall trauma. Regarding the relationship between childhood trauma and AM, 24 studies found a negative relationship between childhood interpersonal trauma and AM; among the articles on non-interpersonal trauma, 10 studies found no relevant relationship; in the studies on overall trauma, 4 articles found negative relationship between overall trauma and AM. The literature explored in our systematic review supports the prevalence of a negative relationship between interpersonal childhood trauma and AM. This relationship is present regardless of psychiatric disorders (e.g., Depression, Post Traumatic Stress Disorder, and Personality Disorders), and in the presence of the latter, AM results even more fragmented. Future research should use more accurate methodologies in identifying and classifying childhood trauma in order to more precisely determine its effect on AM.

Unhealthy behaviors associated with mental health disorders: a systematic comparative review of diet quality, sedentary behavior, and cannabis and tobacco use

Background

There are well-established literatures documenting the associations between mental disorders and unhealthy behaviors such as poor diet quality, sedentary behavior, and cannabis and tobacco use. Few studies have attempted to understand the respective findings in light of each other, however.

Objective

The purpose of this review was to assemble comparable data for each behavior-disorder association and assess the associations in terms of their overall strength. The review aimed to include a representative, but not exhaustive, range of studies that would allow for explorative comparisons.

Methods

Eligible studies were identified via Pubmed searches and citation searching, restricted to publications no older than 2015 written in English. To obtain comparable data, only studies that reported findings as odds ratios were included, and risk of bias related to study samples, behavioral measurement disparities, and control variables was assessed via sensitivity analyses. Findings for each disorder were compared on the basis of different measures of central tendency.

Results

From 3,682 records, 294 studies were included. The review found evidence of associations between each of the four unhealthy behaviors and psychosis, depression, anxiety, bipolar disorder, attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), while personality disorder was only investigated in relation to cannabis and tobacco use. In overall comparison, the associations were generally of similar strength, and only the association between cannabis use and personality disorder was exceptional in terms of being significantly stronger than its counterparts across disorders and across behaviors. Analyses of bias risk identified some influence from behavioral measurement disparities and lack of adequate statistical control, but findings were generally robust across a range of sensitivity analyses.

Conclusion

This explorative and comparative review found that poor diet quality, sedentary behavior, and cannabis and tobacco use are about equally strongly associated with a range of different mental disorders. Given the general nature of these associations, we should probably understand them to reflect a general and shared etiology. However, the findings in this review should be regarded as tentative until confirmed by more comprehensive investigations.

Modelling the effects of the exposome score within the extended psychosis phenotype

It has been reported that cumulative measures of risk factors for psychosis might help to predict its development. However, it remains unknown as to whether these measures are also associated with the extended psychosis phenotype that refers to a continuum of features bridging subclinical symptoms with clinically relevant outcomes. In this study, we aimed to investigate the association of the exposome score (ES) with psychosis risk in a non-clinical population. A total of 1100 non-clinical adults (aged 18-35 years, 51.4% females) with a negative history of psychiatric treatment were recruited. The Prodromal Questionnaire-16 (PQ-16) was used to screen for psychosis risk. Self-reports were used to record environmental exposures. The ES was significantly higher in participants with the positive PQ-16 screening. Specifically, the prevalence of obstetric complications, non-right handedness, all categories of childhood trauma, and problematic cannabis use was significantly higher in this group of participants. A network analysis demonstrated that the ES was directly connected not only to items representing psychotic experiences ("paranoid thoughts", "a lack of control over own ideas or thoughts", "thought echo", and "being distracted by distant sounds") but also those covering depressive or anxiety symptoms ("uninterested in things used to enjoy" and "feeling anxious when meeting people for the first time"). In conclusion, the ES is associated with the extended psychosis phenotype, suggesting its potential to identify individuals who may benefit from further psychosis risk assessment. The ES appears to contribute to non-specific psychopathology, which may, in some cases, progress to psychosis.

De-Salazar P, Alegría M. Association of sociocultural stressors with bipolar disorder onset in Puerto Rican youth growing up as members of a minoritized ethnic group: results from the Boricua Youth Longitudinal Study

Background

The development of bipolar disorder is currently explained by a complex interaction of genetic and environmental factors. Less is known regarding the influence of sociocultural factors. This study aims to evaluate the incidence and impact of sociocultural factors on bipolar disorder onset in two comparable samples of youth growing up in different social settings.

Methods

We leveraged data from two urban population-based cohorts representative of Puerto Rican children growing up in either San Juan (Puerto Rico) or the South Bronx (NYC) and followed up for 17 years. Bipolar disorder diagnoses were based on retrospective self-reports on the World Health Organization Composite International Diagnostic Interview. We used a causal inference approach to estimate associations of sociocultural factors with bipolar disorder onset after adjusting for potential confounders.

Findings

We found that South Bronx children, who grew up as a minoritized group, had twice the risk of bipolar disorder onset as young adults, with an incidence rate of 2.22 new cases per 1000 person-years compared to 1.08 new cases in San Juan (incidence rate difference, 1.13; 95% CI, 0.09-1.20). After adjusting for potential confounders, South Bronx children had the same lifetime hazard of bipolar disorder onset compared to San Juan children. However, our analysis demonstrated that caregivers' exposure to societal cultural stress partially explained the increased risk of bipolar disorder onset in the South Bronx, in addition to the potential contribution of genetics.

Interpretation

Our results provide evidence that societal cultural stress can increase the risk of lifetime bipolar disorder onset in youth growing up as a minoritized group. Addressing stress in minoritized groups might reduce the risk of bipolar disorder onset.

Funding

The Boricua Youth Study has been supported by the National Institutes of HealthMH56401, MH098374, DA033172, and AA020191. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the article.

Does circadian dysrhythmia drive the switch into high- or low-activation states in bipolar I disorder?

OBJECTIVES

Emerging evidence suggests a role of circadian dysrhythmia in the switch between "activation" states (i.e., objective motor activity and subjective energy) in bipolar I disorder.

METHODS

We examined the evidence with respect to four relevant questions: (1) Are natural or environmental exposures that can disrupt circadian rhythms also related to the switch into high-/low-activation states? (2) Are circadian dysrhythmias (e.g., altered rest/activity rhythms) associated with the switch into activation states in bipolar disorder? (3) Do interventions that affect the circadian system also affect activation states? (4) Are associations between circadian dysrhythmias and activation states influenced by other "third" factors?

RESULTS

Factors that naturally or experimentally alter circadian rhythms (e.g., light exposure) have been shown to relate to activation states; however future studies need to measure circadian rhythms contemporaneously with these natural/experimental factors. Actigraphic measures of circadian dysrhythmias are associated prospectively with the switch into high- or low-activation states, and more studies are needed to establish the most relevant prognostic actigraphy metrics in bipolar disorder. Interventions that can affect the circadian system (e.g., light therapy, lithium) can also reduce the switch into high-/low-activation states. Whether circadian rhythms mediate these clinical effects is an unknown but valuable question. The influence of age, sex, and other confounders on these associations needs to be better characterised.

CONCLUSION

Based on the reviewed evidence, our view is that circadian dysrhythmia is a plausible driver of transitions into high- and low-activation states and deserves prioritisation in research in bipolar disorders.

Relationships between childhood trauma and dimensional schizotypy: A network analysis and replication

OBJECTIVES

Childhood trauma (CT) has been found to increase the risk of developing schizophrenia and other psychiatric disorders. Little is known regarding the complex interplay between CT, subclinical psychotic, and affective symptoms in the general population. This cross-sectional study adopted network analysis to examine such a complex relationship. We hypothesized that CT would show strong connections with schizotypy dimensions, and the high schizotypy subgroup would show a network with higher global strength compared with the low schizotypy subgroup.

METHODS

A total of 1813 college students completed a set of self-report questionnaires measuring CT, schizotypal features, bipolar traits, and depressive symptoms. The subscales of these questionnaires were used as nodes, and the partial correlations between nodes were used as edges to construct a network. Network Comparison Tests were used to investigate the differences between participants with high schizotypy and low schizotypy. An independent sample (n = 427) was used to examine the replicability of the results.

RESULTS

Findings from the main dataset showed that CT was closely connected with schizotypy and motivation, after controlling for the inter-relationships between all nodes in the network. Relative to the low schizotypy subgroup, the network of the high schizotypy subgroup showed higher global strength. The two subgroups did not differ in network structure. Network analysis using the replication dataset showed comparable global strength and network structure.

CONCLUSIONS

Our findings support specific links between CT and schizotypy dimensions in healthy youth populations, and such links appear to become stronger in those with high schizotypy.

Diagnosis and management of bipolar disorders

Bipolar disorders (BDs) are recurrent and sometimes chronic disorders of mood that affect around 2% of the world's population and encompass a spectrum between severe elevated and excitable mood states (mania) to the dysphoria, low energy, and despondency of depressive episodes. The illness commonly starts in young adults and is a leading cause of disability and premature mortality. The clinical manifestations of bipolar disorder can be markedly varied between and within individuals across their lifespan. Early diagnosis is challenging and misdiagnoses are frequent, potentially resulting in missed early intervention and increasing the risk of iatrogenic harm. Over 15 approved treatments exist for the various phases of bipolar disorder, but outcomes are often suboptimal owing to insufficient efficacy, side effects, or lack of availability. Lithium, the first approved treatment for bipolar disorder, continues to be the most effective drug overall, although full remission is only seen in a subset of patients. Newer atypical antipsychotics are increasingly being found to be effective in the treatment of bipolar depression; however, their long term tolerability and safety are uncertain. For many with bipolar disorder, combination therapy and adjunctive psychotherapy might be necessary to treat symptoms across different phases of illness. Several classes of medications exist for treating bipolar disorder but predicting which medication is likely to be most effective or tolerable is not yet possible. As pathophysiological insights into the causes of bipolar disorders are revealed, a new era of targeted treatments aimed at causal mechanisms, be they pharmacological or psychosocial, will hopefully be developed. For the time being, however, clinical judgment, shared decision making, and empirical follow-up remain essential elements of clinical care. This review provides an overview of the clinical features, diagnostic subtypes, and major treatment modalities available to treat people with bipolar disorder, highlighting recent advances and ongoing therapeutic challenges.

Association of Primary Immunodeficiencies in Parents With Psychiatric Disorders and Suicidal Behavior in Their Offspring

Importance

Maternal immune activation (MIA) leading to altered neurodevelopment in utero is a hypothesized risk factor for psychiatric outcomes in offspring. Primary antibody immunodeficiencies (PIDs) constitute a unique natural experiment to test the MIA hypothesis of mental disorders.

Objective

To assess the association of maternal and paternal PIDs with psychiatric disorders and suicidal behavior in offspring.

Design, Setting, and Participants

Cohort study of 4 294 169 offspring of parents with and without PIDs living in Sweden at any time between 1973 and 2013. Data were extracted from Swedish nationwide health and administrative registers and were analyzed from May 5 to September 30, 2022. All individuals with diagnoses of PIDs identified between 1973 and 2013 from the National Patient Register were included. Offspring were included if born before 2003. Parent-offspring pairs in which both parents had a history of PIDs were excluded.

Exposures

Lifetime records of parental PIDs according to the International Classification of Diseases, Eighth Revision (ICD-8); International Classification of Diseases, Ninth Revision (ICD-9); and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnostic codes.

Main Outcomes and Measures

Lifetime records of 10 psychiatric disorders and suicidal behavior identified using ICD-8, ICD-9, and ICD-10 diagnostic codes, including suicide attempts and death by suicide, among offspring. Covariates included sex, birth year, parental psychopathology, suicide attempts, and autoimmune diseases. Additional analyses excluded offspring with their own PIDs and autoimmune diseases. Poisson regression models were fitted separately for mothers and fathers to estimate incidence rate ratios (IRRs) and 95% CIs for the risk of psychiatric and suicidal behavior outcomes in the offspring of PID-exposed vs PID-unexposed mothers or fathers.

Results

The cohort included 4 294 169 offspring (2 207 651 males [51.4%]) and 3 954 937 parents (1 987 972 females [50.3%]). A total of 7270 offspring (0.17%) had parents with PIDs, and 4 286 899 offspring had parents without PIDs. In fully adjusted models, offspring of mothers with PIDs had an increased risk of any psychiatric disorder, while no such risks were observed in offspring of fathers with PIDs (IRR, 1.17; 95% CI, 1.10-1.25 vs IRR, 1.03; 95% CI, 0.94-1.14; P < .001). Likewise, an increased risk of suicidal behavior was observed among offspring of mothers with PIDs but not offspring of fathers with PIDs (IRR, 1.20; 95% CI, 1.06-1.36 vs IRR, 1.10; 95% CI, 0.91-1.34; P = .01). For the offspring of mothers with PIDs, the risk of developing any psychiatric disorder was significantly higher for those with mothers with 6 of 10 individual disorders, with IRRs ranging from 1.15 (95% CI, 1.04-1.26) for anxiety and stress-related disorders and 1.15 (95% CI, 1.03-1.30) for substance use disorders to 1.71 (95% CI, 1.37-2.14) for bipolar disorders. Offspring of mothers with both PIDs and autoimmune diseases had the highest risk for any psychiatric disorder (IRR, 1.24; 95% CI, 1.11-1.38) and suicidal behavior (IRR, 1.44; 95% CI, 1.17-1.78).

Conclusions and Relevance

Findings of this cohort study suggest that maternal, but not paternal, PIDs were associated with a statistically significant increased risk of psychiatric disorders and suicidal behavior in the offspring, particularly when PIDs co-occur with autoimmune diseases. These findings align with the MIA hypothesis of mental disorders, but the precise mechanisms remain to be elucidated.

The maladaptive domains according to the alternative model of personality disorders (AMPD) criterion B in patients with affective disorders and temperamental triads related to these domains: two unique profiles

OBJECTIVES

The study aimed to (i) compare the maladaptive domains and facets according to the Alternative Model of Personality Disorders (AMPD) Criterion B in patients with a type II bipolar disorder (BD-II) or major depressive disorder (MDD) with healthy controls (HCs), and (ii) investigating the relationship between affective temperaments and these domains and facets in the total sample.

METHODS

Outpatients diagnosed with current BD-II (n = 37; female 62.2%) or MDD (n = 17; female 82.4%) based on the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria and community HCs (n = 177; female 62.1%) in Kermanshah from July to October 2020 included this case-control study. All participants completed the Personality Inventory for DSM-5 (PID-5), the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A), and the second version of the Beck Depression Inventory (BDI-II). Data were analyzed using analysis of variance (ANOVA), Pearson correlation, and multiple regression.

RESULTS

The score of patients with BD-II in all five domains and those with MDD in three domains including negative affectivity, detachment, and disinhibition are significantly higher than the HCs (p < 0.05). Depressive temperament (related to negative affectivity, detachment, and disinhibition) and cyclothymic temperament (related to antagonism and psychoticism) were the most important correlates of the maladaptive domains.

CONCLUSIONS

Two unique profiles are proposed, including three domains of negative affectivity, detachment, and disinhibition associated with the depressive temperament for MDD, and two domains of antagonism and psychoticism related to cyclothymic temperament for BD-II.

Changes in neurofilament light chain protein (NEFL) in children and adolescents with Schizophrenia and Bipolar Disorder: Early period neurodegeneration

AIM

Neurofilament light chain protein (NEFL), is defined as a structural protein which exists particularly in axones of neurons and is released to the cerum in consequence of neuroaxonal damage. The aim of this study is to investigate the peripheral cerumNEFLlevels of children and adolescents with early onset schizophrenia and bipolar disorder.

METHOD

In this study, we evaluated serum levels of NEFL in children and adolescents (13-17 years) with schizophrenia, bipolar disorder and healthy control group. The study is conducted with 35 schizophrenia, 38 bipolar disorder manic episode patients and 40 healthy controls.

RESULTS

The median age of the patient and control groups was 16 (IQR- Interquartile Range: 2). There was no statistical difference in median age (p = 0.52) and gender distribution(p = 0.53) between groups. NEFL levels of the patients with schizophrenia were significantly higher than the controls. NEFL levels of the patients with bipolar disorder were significantly higher than the controls. Serum levels of NEFL of the schizophrenia were higher than the bipolar disorder; however, the difference was not statistically significant.

CONCLUSION

In conclusion, serum NEFL level, as a confidential marker of neural damage, is increased in the children and adolescents with bipolar disorder and schizophrenia. This result may indicatea degenerative period in neurons of children and adolescents with schizophrenia or bipolar disorder and may play a role in the pathophisiology of these disorders. This result shows that there is neuronal damage in both diseases, but neuronal damage may be more in schizophrenia.

The ethics and management of cannabis use in pregnancy following decriminalisation and licensing for medical use: narrative review

AIMS AND METHOD

As drug policies pertaining to cannabis use become more liberalised, the prevalence of cannabis use in pregnancy could increase. However, there is limited guidance available for clinicians. This paper presents a narrative review of literature published in the past 16 years (2006-2021) to (a) address the impact of legalisation and decriminalisation on the risks, ethics and support of women who use cannabis during pregnancy and (b) develop guidance for clinicians.

RESULTS

Both national and international trends suggest increased use of cannabis over the past decade, while the risks of cannabis use for recreational or medicinal purposes in pregnancy remain unmitigated.

CLINICAL IMPLICATIONS

This review confirmed that the recommendation of cannabinoid-based products for pregnant and breast-feeding women is currently premature. More research is needed to address safety concerns. We discussed navigating ethical concerns and suggest targeted management strategies for clinicians treating pregnant women who choose to use cannabis.

Environmental Factors in the Etiology of Mental Disorders in the Czech Republic

BACKGROUND

Both genetic and environmental factors are important in etiology of mental disorders. Calculating polyenviromic risk/protective scores provides an updated perspective in research on the environmental causes of psychiatric disorders. We aimed to compare environmental risk and protective factors in patients with psychosis or a mood disorder (PSYCH+MOOD) and those with an anxiety disorder (ANX).

METHODS

We administered the internationally accepted questionnaire from the EUropean Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) study, enriched with mood and anxiety disorder-relevant measures, to patients at two large university hospitals in the Czech Republic.

RESULTS

Ninety-four PSYCH+MOOD patients (average age 42.5 years; 46 males) and 52 ANX patients (average age 47.2 years; 17 males) participated. Neither polyenviromic risk score nor polyenviromic protective score differed significantly between PSYCH+MOOD and ANX groups (p = 0.149; p = 0.466, respectively).

CONCLUSION

Scientific validity of the polyenviromic risk/protective score construct must still be demonstrated in large psychiatric samples, ideally in prospective studies. Nevertheless, researchers have already started to investigate environmental factors in the etiology of mental disorders in their complexity, similarly to polygenic risk scores.

Prenatal and perinatal risk factors for bipolar disorder: A systematic review and meta-analysis

BACKGROUND

Perinatal and prenatal risk factors may be implicated in the development of bipolar disorder, but literature lacks a comprehensive account of possible associations.

METHODS

We performed a systematic review and meta-analyses of observational studies detailing the association between prenatal and perinatal risk factors and bipolar disorder in adulthood by searching PubMed, Embase, Web of Science and Psycinfo for articles published in any language between January 1st, 1960 and September 20th, 2021. Meta-analyses were performed when risk factors were available in at least two studies.

FINDINGS

Twenty seven studies were included with 18 prenatal or perinatal factors reported across the literature. Peripartum asphyxia (k = 5, OR = 1.46 [1.02; 2.11]), maternal stress during pregnancy (k = 2, OR = 12.00 [3.30; 43.59]), obstetric complications (k = 6, OR = 1.41 [1.18; 1.69]), and birth weight less than 2500 g (k = 5, OR = 1.28 [1.04; 1.56]) were associated with an increased risk for bipolar disorder.

INTERPRETATION

Perinatal and prenatal risk factors are implicated in the pathogenesis of bipolar disorder, supporting a role of prenatal care in preventing the condition.

The critical periods of cerebral plasticity: A key aspect in a dialog between psychoanalysis and neuroscience centered on the psychopathology of schizophrenia

Through research into the molecular and cellular mechanisms that occur during critical periods, recent experimental neurobiological data have brought to light the importance of early childhood. These have demonstrated that childhood and early environmental stimuli play a part not only in our subjective construction, but also in brain development; thus, confirming Freud's intuition regarding the central role of childhood and early experiences of the environment in our psychological development and our subjective outcomes. "Critical periods" of cerebral development represent temporal windows that mark favorable, but also circumscribed, moments in developmental cerebral plasticity. They also vary between different cortical areas. There are, therefore, strictly defined temporal periods for learning language, music, etc., after which this learning becomes more difficult, or even impossible, to acquire. Now, research into these critical periods can be seen as having a significant part to play in the interdisciplinary dialog between psychoanalysis and neurosciences with regard to the role of early experiences in the etiology of some psychopathological conditions. Research into the cellular and molecular mechanisms controlling the onset and end of these critical periods, notably controlled by the maturation of parvalbumin-expressing basket cells, have brought to light the presence of anomalies in the maturation of these neurons in patients with schizophrenia. Starting from these findings we propose revisiting the psychoanalytic theories on the etiology of psychosis from an interdisciplinary perspective. Our study works from the observation, common to both psychoanalysis and neurosciences, that experience leaves a trace; be it a "psychic" or a "synaptic" trace. Thus, we develop a hypothesis for an "absence of trace" in psychosis; reexamining psychosis through the prism of the biological theory of critical periods in plasticity.

The relationships between use of alcohol, tobacco and coffee in adolescence and mood disorders in adulthood

INTRODUCTION

Alcohol, tobacco and coffee are commonly used substances and use in adolescence has previously been linked to mood disorders. However, few large prospective studies have investigated adolescent use in relation to mental health outcomes in adulthood. The main aim of this study was to examine the prospective associations between alcohol use, cigarette smoking and coffee consumption at age 16 and subsequent mood disorders up to 33 years of age.

METHODS

Data from The Northern Finland Birth Cohort 1986 Study were used and a total of 7660 participants (49.9% male) were included. Associations between alcohol use, cigarette smoking and coffee consumption at age 16 and later diagnoses of major depression and bipolar disorder were examined using multinomial logistic regression analyses.

RESULTS

Mean number of cigarettes/day (OR, 1.23 [95% CI 1.01-1.50]) and mean volume of alcohol consumption (OR, 1.22 [95% CI 1.01-1.47]), but not frequency of excessive drinking, in adolescence were associated with increased risk for subsequent bipolar disorder after adjustment for sex, parental psychiatric disorders, family structure, illicit substance use, and emotional and behavioral problems at age 16. An association between cigarette smoking and major depression attenuated to statistically non-significant when adjusted for emotional and behavioral problems. No associations were observed between adolescent coffee consumption and subsequent mood disorders.

CONCLUSIONS

This is the first study to report an association of adolescent cigarette smoking and subsequent bipolar disorder diagnosis providing grounds for further research and pointing to a place for preventive measures among adolescents.

A revised and extended systematic review and meta-analysis of the relationship between childhood adversity and adult psychiatric disorder

This study aimed to systematically review the evidence for an association between adversity experienced in childhood (≤ 17 years old), and the diagnosis of psychiatric disorder in adulthood. Electronic databases (Scopus, Medline (for Ovid), EMBASE, and PsychINFO) were searched for peer-reviewed, longitudinal cohort studies examining child or adolescent exposure to adversity, and adult-diagnosed depression, anxiety, psychotic disorder, eating disorders, substance abuse disorder, illness anxiety disorder, somatoform disorder, or personality disorder. A total of 39 manuscripts were retained. Results revealed a significant association between the following childhood exposures and adult mental disorder (1.24 ≤ Odds ratios ≤ 2.09): bullying (victimhood, and frequency); emotional abuse; neglect; physical abuse; parental loss; and general maltreatment (unspecified and/or multiple adversity exposure). There were opposing results for being a victim and perpetrator of bullying, and the result for sexual abuse was not statistically significant. There was some evidence of a dose-response relationship with those exposed to multiple forms of maltreatment having more two and a half times odds of developing a mental disorder (Odds ratio = 2.59). The result for sexual abuse is likely an artefact of the prospective assessment of this adversity. In summary, there was strong evidence of an association between childhood adversity and later mental illness, and this supports previously reported meta-analyses. The evidence suggests that childhood and adolescence is an important time for risk for later mental illness, and an important period in which to focus intervention strategies for those known to have been exposed to adversity, particularly multiple adversities.

The Role of Equilibrium between Free Radicals and Antioxidants in Depression and Bipolar Disorder

Background: Increasing evidence suggests that the presence of oxidative stress and disorders of the antioxidant defense system are involved in a wide range of neuropsychiatric disorders, such as bipolar disorder, schizophrenia and major depression, but the exact mechanism remains unknown. This review focuses on a better appreciation of the contribution of oxidative stress to depression and bipolar disorder. Methods: This review was conducted by extracting information from other research and review studies, as well as other meta-analyses, using two search engines, PubMed and Google Scholar. Results: As far as depression is concerned, there is agreement among researchers on the association between oxidative stress and antioxidants. In bipolar disorder, however, most of them observe strong lipid peroxidation in patients, while regarding antioxidant levels, opinions are divided. Nevertheless, in recent years, it seems that on depression, there are mainly meta-analyses and reviews, rather than research studies, unlike on bipolar disorder. Conclusions: Undoubtedly, this review shows that there is an association among oxidative stress, free radicals and antioxidants in both mental disorders, but further research should be performed on the exact role of oxidative stress in the pathophysiology of these diseases.

Mediating role of impaired wisdom in the relation between childhood trauma and psychotic-like experiences in Chinese college students: a nationwide cross-sectional study

BACKGROUND

The association between childhood trauma (CT) and psychotic-like experiences (PLEs) is well-established. Many previous studies have recognized wisdom as a protective factor for mental health, but its role in the relation between CT and PLEs remains unknown. We aimed to investigate the mediating effect of wisdom in the above association among Chinese college students.

METHODS

We conducted a nationwide survey covering 9 colleges across China and recruited a total of 5873 students using online questionnaires between September 14 and October 18, 2021. Convenience sampling was adopted. We employed the San Diego Wisdom Scale (SD-WISE), the Childhood Trauma Questionnaire (CTQ-28), and the 15-item Positive Subscale of the Community Assessment of Psychic Experiences (CAPE-15) to measure the wisdom, CT and PLEs, respectively. Descriptive, correlation, and mediation analysis were utilized.

RESULTS

The positive correlation between CT and PLEs was well-replicated among college students (Pearson's r = 0.30, p < 0.001). Wisdom was negatively associated with CT (Pearson's r = - 0.46, p < 0.001) and frequency of PLEs (Pearson's r = - 0.25, p < 0.001). Total wisdom scores partially mediated the relationship between cumulative childhood trauma, neglect, abuse and PLEs, separately. The mediated model respectively explained 21.9%, 42.54% and 18.27% of the effect of CT on PLEs. Our model further suggested that childhood trauma could be related to PLEs through decreasing the following wisdom components: decisiveness, emotional regulation and prosocial behavior.

CONCLUSION

For the first time, our results suggested that impaired wisdom played a role in the translation from childhood adversity to subclinical psychotic symptoms, implicating wisdom as a possible target for early intervention for psychosis among young individuals. Longitudinal work is warranted to verify the clinical implications.

Schizophrenia, Bipolar and Major Depressive Disorders: Overview of Clinical Features, Neurotransmitter Alterations, Pharmacological Interventions, and Impact of Oxidative Stress in the Disease Process

Psychiatric disorders are one of the leading causes of disability worldwide and affect the quality of life of both individuals and the society. The current understanding of these disorders points toward receptor dysfunction and neurotransmitter imbalances in the brain. Treatment protocols are hence oriented toward normalizing these imbalances and ameliorating the symptoms. However, recent literature has indicated the possible role of depleted levels of antioxidants like glutathione (GSH) as well as an alteration in the levels of the pro-oxidant, iron in the pathogenesis of major psychiatric diseases, viz., schizophrenia (Sz), bipolar disorder (BD), and major depressive disorder (MDD). This review aims to highlight the involvement of oxidative stress (OS) in these psychiatric disorders. An overview of the clinical features, neurotransmitter abnormalities, and pharmacological treatments concerning these psychiatric disorders has also been presented. Furthermore, it attempts to synthesize literature from existing magnetic resonance spectroscopy (MRS) and quantitative susceptibility mapping (QSM) studies for these disorders, assessing GSH and iron, respectively. This manuscript is a sincere attempt to stimulate research discussion to advance the knowledge base for further understanding of the pathoetiology of Sz, BD, and MDD.

Severe mental disorders and vaccinations - a systematic review

OBJECTIVES

People with severe mental illnesses (SMI: schizophrenia, depressive disorder, bipolar disorder) have a high risk of being infected by viruses and suffer a more severe infection illness course than the general population. The aim of this literature review was to elucidate rates as well as immunogenicity and side effects of vaccinations in SMI.

METHODS

All studies in the English or German language, which investigated either prevalence rates or effects of vaccinations in the target groups, were systematically searched in the databank PubMed by three independent authors using the PRISMA guidelines and discussed in more detail.

RESULTS

The search found 24 studies reporting epidemiological data and 16 investigating immunogenicity of vaccinations. The results on prevalence rates, antibody production, inflammation response and side effects were inconsistent. About interactions with psychotropic medication, only two studies on clozapine were found.

CONCLUSIONS

Only a few trials with heterogeneous samples have investigated prevalence and effects of vaccinations in SMI. Sex, age and other factors such as somatic comorbidities and special vaccination programmes have not been considered continuously and may influence rates as well. As individuals with SMI might be at special risk, further research on the willingness to be vaccinated as well as efficacy of vaccinations is needed.

Index of multiple deprivation contributed to common psychiatric disorders: A systematic review and comprehensive analysis

BACKGROUND

Limited studies have been conducted to explore the interaction effects of social environmental and genetic factors on the risks of common psychiatric disorders.

METHODS

56,613-106,695 individuals were collected from the UK Biobank cohort. Logistic or liner regression models were first used to evaluate the associations of index of multiple deprivation (IMD) with bipolar disorder (BD), depression and anxiety in UK Biobank cohort. Then, for the significant IMD associated with BD, depression and anxiety, genome-wide gene-environment interaction study (GWEIS) was performed by PLINK 2.0.

RESULT

Totally, the higher levels of IMD were significantly associated with higher risks of BD, depression and anxiety. For BD, GWEIS identified multiple significant SNPs interacting with IMD, such as rs75182167 for income and rs111841503 for education. For depression and anxiety, GWEIS found significant SNPs interacting with income and education, such as rs147013419 for income and rs142366753 for education.

CONCLUSION

Social environmental deprivations contributed to the risks of psychiatric disorders. Besides, we reported multiple candidate genetic loci interacting with IMD, providing novel insights into the biological mechanism.

Willingness to be vaccinated against COVID-19 is equal in individuals with affective disorders and healthy controls

Affective disorders such as major depressive disorder and bipolar disorder are associated with higher infection rates and a more severe course of coronavirus disease (COVID-19). In turn, COVID-19 could trigger mental disease relapse. Vaccinations lead to a reduction of infections and the prevention of severe courses. This work aims to survey the willingness of individuals with affective disorders to get vaccinated and concerns about vaccinations.

METHODS

An online study (April-May 2021) assessed the current infection and vaccination rate amongst individuals with affective disorder in Austria by surveying attitudes towards the vaccination, the willingness to get vaccinated soon and possible reasons for decision. The analyses included 59 individuals with affective disorders and 59 healthy controls, matched for sex and age.

RESULTS

There was an overall high willingness to get vaccinated against COVID-19. Individuals with affective disorders were more skeptical about vaccinations in general but there was no significant difference between the groups in the willingness to get vaccinated against COVID-19. In both groups reasons for waiting were mainly fears of acute and/or long-term side effects and the fast development of the vaccines.

LIMITATIONS

It was a cross sectional design. Due to the online design, no objective rating of current psychopathological symptoms was assessed. Willingness to get vaccinated in general and against COVID-19 in particular were self-created variables, whereas item statistics and factor analysis were conducted.

DISCUSSION

Because of the higher risk for individuals with affective disorders, preventive strategies like vaccinating should be promoted in this group. It is important to help individuals with AD to overcome barriers such as negative beliefs and concerns about acute and/or long-term side effects.

The U-shaped relationship between parental age and the risk of bipolar disorder in the offspring: A systematic review and meta-analysis

Parenthood age may affect the risk for the development of different psychiatric disorders in the offspring, including bipolar disorder (BD). The present systematic review and meta-analysis aimed to appraise the relationship between paternal age and risk for BD and to explore the eventual relationship between paternal age and age at onset of BD. We searched the MEDLINE, Scopus, Embase, PsycINFO online databases for original studies from inception, up to December 2021. Random-effects meta-analyses were conducted. Sixteen studies participated in the qualitative synthesis, of which k = 14 fetched quantitative data encompassing a total of 13,424,760 participants and 217,089 individuals with BD. Both fathers [adjusted for the age of other parent and socioeconomic status odd ratio - OR = 1.29(95%C.I. = 1.13-1.48)] and mothers aged ≤ 20 years [(OR = 1.23(95%C.I. = 1.14-1.33)] had consistently increased odds of BD diagnosis in their offspring compared to parents aged 25-29 years. Fathers aged ≥ 45 years [adjusted OR = 1.29 (95%C.I. = 1.15-1.46)] and mothers aged 35-39 years [OR = 1.10(95%C.I. = 1.01-1.19)] and 40 years or older [OR = 1.2(95% C.I. = 1.02-1.40)] likewise had inflated odds of BD diagnosis in their offspring compared to parents aged 25-29 years. Early and delayed parenthood are associated with an increased risk of BD in the offspring. Mechanisms underlying this association are largely unknown and may involve a complex interplay between psychosocial, genetic and biological factors, and with different impacts according to sex and age range. Evidence on the association between parental age and illness onset is still tentative but it points towards a possible specific effect of advanced paternal age on early BD-onset.

Circulating miRNAs as Potential Biomarkers for Patient Stratification in Bipolar Disorder: A Combined Review and Data Mining Approach

Bipolar disorder is a debilitating psychiatric condition that is shaped in a concerted interplay between hereditary and triggering risk factors. Profound depression and mania define the disorder, but high clinical heterogeneity among patients complicates diagnosis as well as pharmacological intervention. Identification of peripheral biomarkers that capture the genomic response to the exposome may thus progress the development of personalized treatment. MicroRNAs (miRNAs) play a prominent role in of post-transcriptional gene regulation in the context of brain development and mental health. They are coordinately modulated by multifarious effectors, and alteration in their expression profile has been reported in a variety of psychiatric conditions. Intriguingly, miRNAs can be released from CNS cells and enter circulatory bio-fluids where they remain remarkably stable. Hence, peripheral circulatory miRNAs may act as bio-indicators for the combination of genetic risk, environmental exposure, and/or treatment response. Here we provide a comprehensive literature search and data mining approach that summarize current experimental evidence supporting the applicability of miRNAs for patient stratification in bipolar disorder.

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.

Limited association between infections, autoimmune disease and genetic risk and immune activation in severe mental disorders

BACKGROUND

Low-grade inflammation may be part of the underlying mechanism of schizophrenia and bipolar disorder. We investigated if genetic susceptibility, infections or autoimmunity could explain the immune activation.

METHODS

Seven immune markers were selected based on indicated associations to severe mental disorders (IL-1Ra, sIL-2R, IL-18, sgp130, sTNFR-1, APRIL, ICAM-1) and measured in plasma of patients with schizophrenia (SCZ, N = 732) and bipolar spectrum disorders (BD, N = 460) and healthy controls (HC, N = 938). Information on rate of infections and autoimmune diseases were obtained from Norwegian national health registries for a twelve-year period. Polygenic risk scores (PRS) of SCZ and BD were calculated from genome-wide association studies. Analysis of covariance were used to test effects of infection rate, autoimmune disease and PRS on differences in immune markers between patients and HC.

RESULTS

Infection rate differed between all groups (BD > HC > SCZ, all p < 0.001) whereas autoimmune disease was more frequent in BD compared to SCZ (p = 0.004) and HC (p = 0.003). sIL-2R was positively associated with autoimmune disease (p = 0.001) and negatively associated with PRS of SCZ (p = 0.006) across SCZ and HC; however, associations represented only small changes in the difference of sIL-2R levels between SCZ and HC.

CONCLUSION

There were few significant associations between rate of infections, autoimmune disease or PRS and altered immune markers in SCZ and BD, and the detected associations represented only small changes in the immune aberrations. The findings suggest that most of the low-grade inflammation in SCZ and BD is explained by other factors than the underlying PRS, autoimmunity and infection rates.

Adverse Childhood Experiences Predict the Phenome of Affective Disorders and These Effects Are Mediated by Staging, Neuroimmunotoxic and Growth Factor Profiles

Adverse childhood experiences (ACEs) enhance pro-inflammatory and pro-oxidant responses. In affective disorders, recent precision nomothetic psychiatry studies disclosed new pathway phenotypes, including an ROI—reoccurrence of illness (ROI)—oxidative stress latent construct. The aim of the present study is to delineate a) whether ACEs sensitize the M1 macrophage, the T helper cells (Th)1, Th2, and Th17, the IRS (immune-inflammatory-responses system), the CIRS (compensatory immunoregulatory system), and the neuroimmunotoxic and growth factor (GF) profiles and whether they are associated with ROI and the phenome of affective disorders and b) the molecular pathways underpinning the effects of the ACEs. We collected supernatants of stimulated (5 μg/mL of PHA and 25 μg/mL of LPS) and unstimulated diluted whole blood in 20 healthy controls and 30 depressed patients and measured a panel of 27 cytokines/GF using a Luminex method. ACEs (comprising mental and physical trauma, mental neglect, domestic violence, family history of mental disease, and parent loss) are accompanied by the increased stimulated, but not unstimulated, production of M1, Th1, Th2, Th17, IRS, neuroimmunotoxic, and GF profiles and are strongly correlated with ROI and the phenome. A latent vector extracted from the ROI features (recurrent episodes and suicidal behaviors) and the IRS/neuroimmunotoxic/GF profiles explains 66.8% of the variance in the phenome and completely mediates the effects of ACEs on the phenome. Enrichment analysis showed that the ACE-associated sensitization of immune/GF profiles involves JAK-STAT, nuclear factor-κB, tumor necrosis factor-α, G-protein coupled receptor, PI3K/Akt/RAS/MAPK, and hypoxia signaling. In summary, the ACE-induced sensitization of immune pathways and secondary immune hits predicts the phenome of affective disorders.

Going beyond risk factor: Childhood maltreatment and associated modifiable targets to improve life-long outcomes in mood disorders

Childhood maltreatment increases risk for mood disorders and is associated with earlier onset-and more pernicious disease course following onset-of mood disorders. While the majority of studies to date have been cross-sectional, longitudinal studies are emerging and support the devastating role(s) childhood maltreatment has on development of, and illness course in, mood disorders. This manuscript extends prior reviews to emphasize more recent work, highlighting longitudinal data, and discusses treatment studies that provide clues to mechanisms that mediate disease risk, course, relapse, and treatment response. Evidence suggesting systemic inflammation, alterations in hypothalamic-pituitary-adrenal (HPA) axis function and corticotropin-releasing factor (CRF) neural systems, genetic and other familial factors as mechanisms that mediate risk and onset of, and illness course in, mood disorders following childhood maltreatment is discussed. Risky behaviors following maltreatment, e.g., substance use and unhealthy lifestyles, may further exacerbate alterations in the HPA axis, CRF neural systems, and systematic inflammation to contribute to a more pernicious disease course. More research on sex differences and the impact of maltreatment in vulnerable populations is needed. Future research needs to be aimed at leveraging knowledge on modifiable targets, going beyond childhood maltreatment as a risk factor, to inform prevention and treatment strategies and foster trauma-informed care.

Geographical Variation in Mental Hospital Discharges in Greece: A Nationwide Study (1999–2012)

Background: The primary goal of this study is to estimate the pattern of hospital discharges throughout Greece due to mental disorders between 1999 and 2012. Methods: Data for discharges were obtained from the Hellenic Statistical Authority. A sex- and age-adjusted proportional hospitalization ratio (PHR) was used to estimate the ratio between the hospitalizations in each prefecture and the overall hospitalizations. Additionally, age-adjusted admission rates and hospitalization days were calculated for each sex. Descriptive and time series analysis were conducted to understand the epidemiological characteristics and to investigate the trend of annual PHR, respectively. Correlation between disorders and sociodemographic characteristics was also tested. Global and local spatial analysis was conducted to assess the spatial homogeneity of disorders and to detect any clusters of similar values. Results: More males (55%) were hospitalized. Schizophrenic and other psychoses were stated as the primary diagnosis of discharges (54.3%) for mental disorders, contributing to the highest annual mean number of hospitalization-days for male (296.9) and female patients (341.0). Most patients were out of the workforce, and most patients with drug dependence (74.5%) and schizophrenia and other psychoses (55.9%) remained unmarried. Higher PHRs were discovered in the north, while schizophrenic and other psychoses (R = 0.492), affective psychoses (R = 0.534), senile and presenile organic psychotic conditions (R = 0.543) were correlated with alcohol consumption (p < 0.001). Conclusions: The study provides evidence of geographical variation of discharges due to mental disorders and a significant association between disorders and alcohol consumption, marriage status and absence of the workforce.

Childhood adversities and bipolar disorder: a neuroimaging focus

Early-life adverse events or childhood adversities (CAs) are stressors and harmful experiences severely impacting on a child's wellbeing and development. Examples of CAs include parental neglect, emotional and physical abuse and bullying. Even though the prevalence of CAs and their psychological effects in both healthy and psychiatric populations is established, only a paucity of studies have investigated the neurobiological firms associated with CAs in bipolar disorder (BD). In particular, the exact neural mechanisms and trajectories of biopsychosocial models integrating both environmental and genetic effects are still debated. Considering the potential impact of CAs on BD, including its clinical manifestations, we reviewed existing literature discussing the association between CAs and brain alterations in BD patients. Results showed that CAs are associated with volume alterations of several grey matter regions including the hippocampus, thalamus, amygdala and frontal cortex. A handful of studies suggest the presence of alterations in the corpus callosum and the pre-fronto-limbic connectivity at rest. Alterations in these regions of the brain of patients with BD are possibly due to the effect of stress produced by CAs, being hippocampus part of the hypothalamus-pituitary-adrenal axis and thalamus together with amygdala filtering sensory information and regulating emotional responses. However, results are mixed possibly due to the heterogeneity of methods and study design. Future neuroimaging studies disentangling between different types of CAs or differentiating between BD sub-types are needed in order to understand the link between CAs and BD.

Differentiation and comorbidity of bipolar disorder and attention deficit and hyperactivity disorder in children, adolescents, and adults: A clinical and nosological perspective

Bipolar Disorder (BD) and Attention Deficit and Hyperactivity Disorder (ADHD) are mental disorders with high degree of lifetime comorbidity. Both BD and ADHD are disorders with onset in childhood and early adolescence. Both disorders are often undiagnosed, misdiagnosed, and sometimes overdiagnosed, leading to high rates of morbidity and disability. The psychiatric and behavioral symptoms associated with ADHD and BD have significant overlap. Albeit the existence of a large body of literature, it is far from being clear whether comorbidity can be explained by the confounding overlap of operationally defined criteria or whether it reflects a genuine comorbidity of two biologically distinct disorders. The aim of this paper is to recognize and/or differentiate the pattern of ADHD across the course of BD from a nosological point of view, focusing on specific clinical and neurobiological dimensions. We found that some critical issues may help to fulfill the purpose of our perspective. We suggest that the relationship between ADHD and BD, based on clinical, developmental, and epidemiological commonalities, can be better clarified using four different scenarios.

Substance use as a risk factor for bipolar disorder: A systematic review

Detecting substance use as a predictor of bipolar disorder (BD) is important for clinicians to perform accurate and early diagnosis, as well as better manage the treatment of individuals with BD. The aim of this systematic review was to describe whether substance use is a predictor of BD. A literature search was conducted using the following databases: PubMed, PsycINFO, and Embase. All eligible studies published up to February 9, 2021 were included. This systematic review included 22 studies. We found that 66.7% of the studies assessing overall substance use found that overall substance use was a risk factor for BD. Regarding the specific substances assessed, cannabis use was described as a risk factor for BD in 55.6% of the studies, nonmedical use of prescription medications was a risk factor for BD in 50% of the studies, nicotine was found as a risk factor for BD in 50% of the studies, and alcohol use was described as a risk factor for BD in 42.9% of the studies assessing it. Only one study assessed whether cocaine use was a risk factor for BD and found a significant association. Interestingly, some studies suggested that the greater frequency of cannabis use was associated with greater risk to develop BD or hypomanic/manic symptoms. In conclusion, there is evidence supporting that substance use is a risk factor for BD. Importantly, when assessing the risk factors for BD related to psychoactive substance use, special attention should be given for the frequency of cannabis use.

Maternal perceived bonding towards the infant and parenting stress in women at risk of postpartum psychosis with and without a postpartum relapse

BACKGROUND

Postpartum psychosis (PP) is the most severe psychiatric disorder associated with childbirth. However, there is little research on maternal bonding towards the infant and parenting stress in this clinical population.

METHODS

We investigated maternal bonding during pregnancy and post-partum in 75 women: 46 at risk of PP (AR), because of a DSM-IV diagnosis of bipolar disorder, schizoaffective disorder or previous PP, and 29 healthy controls. Of the AR women, 19 developed a psychiatric relapse within 4 weeks' post-partum (AR-unwell), while 27 remained symptom-free (AR-well). We investigated childhood maltreatment, parenting stress and psychiatric symptoms as potential predictors of maternal bonding.

RESULTS

In pregnancy, AR-unwell women reported a more negative affective experience towards their infants than AR-well women (d = 0.87, p = .001), while postnatally there was no significant difference in bonding. In contrast, AR women as a group reported a more negative affective experience than HC postnatally (d = 0.69, p = .002; d = 0.70, p = .010), but not antenatally. Parenting stress and psychiatric symptoms significantly predicted less optimal postnatal bonding (b = -0.10, t = -4.29, p < .001; b = -0.37, t = -4.85, p < .001) but only psychiatric symptoms explained the difference in bonding between AR and HC (b = -1.18, 95% BCa CI [-2.70,-0.04]).

LIMITATIONS

A relatively small sample size precluded a more in-depth investigation of underlying pathways.

CONCLUSION

This study provides new information on maternal bonding in women at risk of PP, and particularly in those that do and do not develop a postpartum relapse. The results suggest that improving maternal symptoms and parenting stress in the perinatal period in women at risk of PP could also have positive effects on bonding.

Developmental Profile of Psychiatric Risk Associated With Voltage-Gated Cation Channel Activity

BACKGROUND

Recent breakthroughs in psychiatric genetics have implicated biological pathways onto which genetic risk for psychiatric disorders converges. However, these studies do not reveal the developmental time point(s) at which these pathways are relevant.

METHODS

We aimed to determine the relationship between psychiatric risk and developmental gene expression relating to discrete biological pathways. We used postmortem RNA sequencing data (BrainSeq and BrainSpan) from brain tissue at multiple prenatal and postnatal time points, with summary statistics from recent genome-wide association studies of schizophrenia, bipolar disorder, and major depressive disorder. We prioritized gene sets for overall enrichment of association with each disorder and then tested the relationship between the association of their constituent genes with their relative expression at each developmental stage.

RESULTS

We observed relationships between the expression of genes involved in voltage-gated cation channel activity during early midfetal, adolescence, and early adulthood time points and association with schizophrenia and bipolar disorder, such that genes more strongly associated with these disorders had relatively low expression during early midfetal development and higher expression during adolescence and early adulthood. The relationship with schizophrenia was strongest for the subset of genes related to calcium channel activity, while for bipolar disorder, the relationship was distributed between calcium and potassium channel activity genes.

CONCLUSIONS

Our results indicate periods during development when biological pathways related to the activity of calcium and potassium channels may be most vulnerable to the effects of genetic variants conferring risk for psychiatric disorders. Furthermore, they indicate key time points and potential targets for disorder-specific therapeutic interventions.

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

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

Is being born in spring significantly associated with early-onset bipolar affective disorder? A case-control study

Few studies have investigated relationships between birth season and early-onset bipolar affective disorder (BAD) in young adults. In the current study, birth season was compared in patients with early-onset BAD and in sex-matched and age-matched controls. A total of 957 patients aged <25 years of age from three hospitals in the North China Plain region were enrolled in the study. Sex-matched and age-matched control group data were collected in universities and schools via questionnaires. The R*C chi-square test was used to assess distributional differences in season of birth both in the patient and control group. A binary logistic regression model adjusted for age and sex was used to evaluate associations between season of birth and BAD. Using spring as the reference season, BAD patients showed significantly lower odds ratios of being born in any other season. There were associations between birth season and early-onset BAD, and early-onset BAD patients were more likely to have been born in spring. These data have implications for future disease prevention strategies and future research.

Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions

Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.