Although significant associations of childhood adversities with adult mental disorders are widely documented, most studies focus on single childhood adversities predicting single disorders.

To examine joint associations of 12 childhood adversities with first onset of 20 DSM–IV disorders in World Mental Health (WMH) Surveys in 21 countries.

Nationally or regionally representative surveys of 51 945 adults assessed childhood adversities and lifetime DSM–IV disorders with the WHO Composite International Diagnostic Interview (CIDI).

Childhood adversities were highly prevalent and interrelated. Childhood adversities associated with maladaptive family functioning (e.g. parental mental illness, child abuse, neglect) were the strongest predictors of disorders. Co-occurring childhood adversities associated with maladaptive family functioning had significant subadditive predictive associations and little specificity across disorders. Childhood adversities account for 29.8% of all disorders across countries.

Childhood adversities have strong associations with all classes of disorders at all life-course stages in all groups of WMH countries. Long-term associations imply the existence of as-yet undetermined mediators.

Suicide is a leading cause of death worldwide, but the precise effect of childhood adversities as risk factors for the onset and persistence of suicidal behaviour (suicide ideation, plans and attempts) are not well understood.

To examine the associations between childhood adversities as risk factors for the onset and persistence of suicidal behaviour across 21 countries worldwide.

Respondents from nationally representative samples (η = 55 299) were interviewed regarding childhood adversities that occurred before the age of 18 years and lifetime suicidal behaviour.

Childhood adversities were associated with an increased risk of suicide attempt and ideation in both bivariate and multivariate models (odds ratio range 1.2–5.7). The risk increased with the number of adversities experienced, but at a decreasing rate. Sexual and physical abuse were consistently the strongest risk factors for both the onset and persistence of suicidal behaviour, especially during adolescence. Associations remained similar after additional adjustment for respondents' lifetime mental disorder status.

Childhood adversities (especially intrusive or aggressive adversities) are powerful predictors of the onset and persistence of suicidal behaviours.

The epidemiology of rapid-cycling bipolar disorder in the community is largely unknown.

To investigate the epidemiological characteristics of rapid-cycling and non-rapid-cycling bipolar disorder in a large cross-national community sample.

The Composite International Diagnostic Interview (CIDI version 3.0) was used to examine the prevalence, severity, comorbidity, impairment, suicidality, sociodemographics, childhood adversity and treatment of rapid-cycling and non-rapid-cycling bipolar disorder in ten countries (n = 54 257).

The 12-month prevalence of rapid-cycling bipolar disorder was 0.3%. Roughly a third and two-fifths of participants with lifetime and 12-month bipolar disorder respectively met criteria for rapid cycling. Compared with the non-rapid-cycling, rapid-cycling bipolar disorder was associated with younger age at onset, higher persistence, more severe depressive symptoms, greater impairment from depressive symptoms, more out-of-role days from mania/hypomania, more anxiety disorders and an increased likelihood of using health services. Associations regarding childhood, family and other sociodemographic correlates were less clear cut.

The community epidemiological profile of rapid-cycling bipolar disorder confirms most but not all current clinically based knowledge about the illness.

Community studies about the association of headache with both childhood family adversities and depression/anxiety disorders are limited.

To assess the independent and joint associations of childhood family adversities and early-onset depression and anxiety disorders with risks of adult-onset headache.

Data were pooled from cross-sectional community surveys conducted in ten Latin and North American, European and Asian countries (n=18 303) by using standardised instruments. Headache and a range of childhood family adversities were assessed by self-report.

The number of childhood family adversities was associated with adult-onset headache after adjusting for gender, age, country and early-onset depression/anxiety disorder status (for one adversity, hazard ratio (HR)=1.22–1.6; for two adversities, HR=1.19–1.67; for three or more adversities, HR=1.37–1.95). Early and current onset of depression/anxiety disorders were independently associated (HR=1.42–1.89) with adult-onset headache after controlling for number of childhood family adversities.

The findings call for a broad developmental perspective concerning risk factors for development of headache.