AbstractBackgroundThere is concern that rates of mental disorders may be increasing although findings disagree. Using an innovative design with a daughter-mother data set we assess whether there has been a generational increase in lifetime ever rates of major depressive disorder, generalised anxiety disorder, panic disorder, and post-traumatic stress disorder (PTSD) experienced prior to 30 years of age.MethodsPregnant women were recruited during 1981–1983 and administered the Composite International Diagnostic Interview (CIDI) at the 27-year follow-up (2008–11). Offspring were administered the CIDI at the 30-year follow-up (2010–2014). Comparisons for onset of diagnosis are restricted to daughter and mother dyads up to 30 years of age. To address recall bias, disorders were stratified into more (≥12 months duration) and less persistent episodes (< 12 months duration) for the purposes of comparison. Sensitivity analyses with inflation were used to account for possible maternal failure to differentially recall past episodes.ResultsWhen comparing life time ever diagnoses before 30 years, daughters had higher rates of persistent generalised anxiety disorder, and less persistent major depressive disorder, generalised anxiety disorder and PTSD.ConclusionsIn the context of conflicting findings concerning generational changes in mental disorders we find an increase in generational rates of persistent generalised anxiety disorders and a range of less persistent disorders. It is not clear whether this finding reflects actual changes in symptom levels over a generation or whether there has been a generational change in recognition of and willingness to report symptoms of mental illness.