Abstract
This thesis comprises three studies which examined aspects of DSM-III-R alcohol dependence in late adolescence and young adulthood in a cohort of over a thousand individuals assessed prospectively since birth. The first study examined the structure and diagnostic utility of the DSM-III-R criteria for alochol dependence in late adolescence and young adulthood. The second study examined concurrent and longitudinal comorbidity between alcohol dependence and non-alcohol psychiatric disorders. The third study examined the role of early onset of alcohol use in the development of alcohol dependence in late adolescence and young adulthood.