Associations between specific parent and offspring mental disorders are likely to have been overestimated in studies that have failed to control for parent comorbidity.

To examine the associations of parent with respondent disorders.

Data come from the World Health Organization (WHO) World Mental Health Surveys (n = 51 507). Respondent disorders were assessed with the Composite International Diagnostic Interview and parent disorders with informant-based Family History Research Diagnostic Criteria interviews.

Although virtually all parent disorders examined (major depressive, generalised anxiety, panic, substance and antisocial behaviour disorders and suicidality) were significantly associated with offspring disorders in multivariate analyses, little specificity was found. Comorbid parent disorders had significant sub-additive associations with offspring disorders. Population-attributable risk proportions for parent disorders were 12.4% across all offspring disorders, generally higher in high- and upper-middle- than low-/lower-middle-income countries, and consistently higher for behaviour (11.0–19.9%) than other (7.1–14.0%) disorders.

Parent psychopathology is a robust non-specific predictor associated with a substantial proportion of offspring disorders.

Little is known about the cross-national population prevalence or correlates of personality disorders.

To estimate prevalence and correlates of DSM–IV personality disorder clusters in the World Health Organization World Mental Health (WMH) Surveys.

International Personality Disorder Examination (IPDE) screening questions in 13 countries (n = 21 162) were calibrated to masked IPDE clinical diagnoses. Prevalence and correlates were estimated using multiple imputation.

Prevalence estimates are 6.1% (s.e. = 0.3) for any personality disorder and 3.6% (s.e. = 0.3), 1.5% (s.e. = 0.1) and 2.7% (s.e. = 0.2) for Clusters A, B and C respectively. Personality disorders are significantly elevated among males, the previously married (Cluster C), unemployed (Cluster C), the young (Clusters A and B) and the poorly educated. Personality disorders are highly comorbid with Axis I disorders. Impairments associated with personality disorders are only partially explained by comorbidity.

Personality disorders are relatively common disorders that often co-occur with Axis I disorders and are associated with significant role impairments beyond those due to comorbidity.