Abstract
BACKGROUND: There 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. METHODS: Pregnant 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. RESULTS: When 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. CONCLUSIONS: In 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.