Neural, endocrine, and immune stress mediators are hypothesized to increase risks of diverse chronic diseases, including arthritis. Retrospective data from the World Mental Health Surveys (N=18,309) were employed to assess whether adult onset of arthritis was associated with childhood adversities and early onset psychological disorder. Cox proportional hazard models assessed the association of number of childhood adversities and the presence of early onset psychological disorder with arthritis age of onset. Controlling for age, sex, and early onset mental disorder, relative to persons with no childhood adversities, persons with two adversities had an increased risk of adult onset arthritis (hazard ratio=1.27, 95% CI=1.08, 1.50), while persons with three or more adversities had a higher risk (HR=1.44, CI=1.24, 1.67). Early onset depressive and/or anxiety disorder was associated with an increased risk of adult onset arthritis after controlling for childhood adversities (HR=1.43, CI=1.28, 1.61). Since psychosocial stressors may be broad spectrum risk factors that increase risks of diverse chronic conditions in later life (e.g. arthritis, heart disease, diabetes, asthma, and chronic pain), prospective studies of childhood psychosocial stressors may be most productive if multiple disease outcomes are assessed in the same study. Results from this study provide methodological guidance for future prospective studies of the relationship between childhood psychosocial stressors and subsequent risk of adult onset arthritis.