During the past year, we have continued to analyze the data from this unique prospective cohort study that covers a total observation period of 30 years for this cohort of young adults who have been followed since the age of 18. In collaboration with our colleagues in Zurich, we are preparing an analysis describing the frequency of occurrence of mental disorders across adulthood, taking into account information from the latest wave of follow-up in 2008. This will be the only study to describe these patterns among a cohort starting in young adulthood. Analyses are conducted to approximate the lifetime risk of disorders through age 50. Results indicate that mental disorders occur relatively commonly across this age range;lifetime risks range from 1.21% for Bipolar I Disorder to 32.54% for Major Depressive Disorder. We have also undertaken a study investigating patterns of sleep across adulthood and the relationship between sleep patterns and mental disorders. While a substantial body of research has investigated the occurrence and course of sleep disorders in adults, most longitudinal studies of sleep patterns have focused on adolescents and older adults. Thus, the Zurich Cohort Study provides a unique opportunity to assess basic sleep parameters such as bedtime, sleep time, and sleep duration across the course of middle adulthood. Preliminary results indicate that while average sleep parameters are relatively stable across adulthood, associations between sleep and mental disorders may change. These are most pronounced for substance use disorders;while differences in sleep duration between those with different groups of disorders are apparent from about age 30-40, these differences appear to diminish by age 50. Public Health Impact: These studies provide valuable insight into the nature of mental disorders in adulthood and the relationship between mental disorders and physiological processes such as sleep. The Zurich Cohort Study is an extremely valuable data source, as it is the longest community-based longitudinal study in which participants were enrolled at the beginning of adulthood. Data on the frequency of occurrence of mental disorders are important for planning interventions and service delivery and for research on etiology. Investigation into associations between mental disorders and sleep will ultimately help us learn more about the nature of mental disorders by connecting them to other physiological processes controlled by the brain. Future Plans: During the next year, in addition to completing the projects described above, we plan to analyze the 30 year follow up data on the following topics: 1) the structure of psychopathology across adulthood, including the structure of specific disorders, comorbidity of mental disorders, and comorbidity between mental and physical disorders;2) the course of psychopathology, including the prevalence and correlates of chronic conditions that are present throughout adulthood;3) the spectrum of mania, hypomania, and depression, including order of onset and patterns across age;and 4) the reliability of reported age of onset of mental disorders in communitybased studies.
