Poster #M153 ENVIRONMENTAL RISK FACTORS, PRODROMAL PSYCHOTIC SYMPTOMS AND PSYCHOPATHOLOGY OF CHILD AND ADOLESCENT OFFSPRING OF PARENTS WITH BIPOLAR DISORDER, SCHIZOPHRENIA AND COMMUNITY CONTROLS. THE BIPOLAR AND SCHIZOPHRENIA YOUNG OFFSPRING STUDY (BASYS)

Abstract Background There is replicated evidence of a shared genetic load between affective and non-affective psychosis, but much less is known of whether affective psychosis is affected by the same environmental risk factors as well. The aim of this review and meta-analysis is to study the association between specific environmental risk factors of interest previously associated with schizophrenia and later affective psychoses (bipolar disorder and psychotic depression). Methods A systematic search of prospective studies was conducted in MEDLINE, EMBASE and PsycINFO databases, supplemented by hand searching. Selected exposures included: paternal age, maternal infection, obstetric and perinatal factors, childhood trauma, childhood infection, urbanicity, migration, stressful life events, head injury and cannabis or substance use. Relevant studies were selected systematically among those fulfilling inclusion criteria, and effect sizes were extracted. Pooled information was presented for those factors with enough number studies to combine extracted effect sizes, while the rest were presented in a narrative way. Results Approximately 60 studies addressing the associations between environmental risk factors of interest and later affective psychoses were identified. The compiled studies showed that paternal age, early gestational age, lifetime cannabis use, parental death during childhood and ethnic minority in UK are associated with future development of affective psychosis. Discussion These results show that, as per genetics, there may be some overlap in the environmental load between schizophrenia and affective psychosis, suggesting general risks for psychosis rather than diagnostic specific risks. Nonetheless, publish studies for some factors in this subgroup of patients are still scarce. More longitudinal studies addressing specific association between environmental risk factors and affective psychosis are warranted.

Download Full-text

Immuno-inflammation in bipolar disorder: Genetic and environmental risk factors

Neurology Psychiatry and Brain Research ◽

10.1016/j.npbr.2015.12.036 ◽

2016 ◽

Vol 22 (1) ◽

pp. 15-16

Author(s):

Marion Leboyer ◽

Ryad Tamouza

Keyword(s):

Risk Factors ◽

Bipolar Disorder ◽

Environmental Risk ◽

Environmental Risk Factors

Download Full-text

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

Frontiers in Genetics ◽

10.3389/fgene.2021.686666 ◽

2021 ◽

Vol 12 ◽

Author(s):

Natassia Robinson ◽

Sarah E. Bergen

Keyword(s):

Risk Factors ◽

Bipolar Disorder ◽

Environmental Factors ◽

Environmental Risk ◽

Genetic Risk ◽

Childhood Adversity ◽

Environmental Exposures ◽

Genetic Risk Factors ◽

Environmental Risk Factors ◽

Early Gene

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.

Download Full-text

Epidemiology and risk factors for bipolar disorder

Therapeutic Advances in Psychopharmacology ◽

10.1177/2045125318769235 ◽

2018 ◽

Vol 8 (9) ◽

pp. 251-269 ◽

Cited By ~ 62

Author(s):

Tobias A. Rowland ◽

Steven Marwaha

Keyword(s):

Risk Factors ◽

Bipolar Disorder ◽

Environmental Risk ◽

Population Level ◽

Environmental Risk Factors ◽

Mental Illnesses ◽

Sufficient Evidence ◽

Specific Gene ◽

Potential Risk Factors ◽

Genetic And Environmental Factors

Bipolar disorder is a multifactorial illness with uncertain aetiology. Knowledge of potential risk factors enables clinicians to identify patients who are more likely to develop bipolar disorder, which directs further investigation, follow up and caution when prescribing. Ideally, identifying directly causative factors for bipolar disorder would enable intervention on an individual or population level to prevent the development of the illness, and improve outcomes through earlier treatment. This article reviews the epidemiology of bipolar disorder, along with putative demographic, genetic and environmental risk factors, while assessing the strength of these associations and to what extent they might be said to be ‘causative’. While numerous genetic and environmental risk factors have been identified, the attributable risk of individual factors is often small, and most are not specific to bipolar disorder but are associated with several mental illnesses. Therefore, while some genetic and environmental factors have strong evidence supporting their association with bipolar disorder, fewer have sufficient evidence to establish causality. There is increasing interest in the role of specific gene–environment interactions, as well as the mechanisms by which risk factors interact to lead to bipolar disorder.

Download Full-text