My research investigates the epidemiology of common mental illnesses in the general population. I frequently use data from longitudinal cohort studies, such as the 1946 British Birth Cohort, to investigate longitudinal and life-course processes surrounding depression and anxiety. I am particularly interested in identifying early-life factors that may predict depression and anxiety later in life, including how various developmental factors and environmental effects interact to affect mental health in adolescence and adulthood. I am also interested in long-term outcomes of childhood and adolescent mental disorders, and how these disorders progress over time. Finally, I have interests in the long-term outcomes associated with treatment for mental disorders, and the epidemiology of suicidal behaviour.