Results from a longitudinal twin study combining diagnostic interviews and registry data on personality, mental disorders, and substance use

The Norwegian Institute of Public Health Twin Panel has followed a population-based twin sample since 1998 with questionnaires and interviews and in governmental health registries. The diagnostic interviews include DSM... [ view full abstract ]

The Norwegian Institute of Public Health Twin Panel has followed a population-based twin sample since 1998 with questionnaires and interviews and in governmental health registries. The diagnostic interviews include DSM criteria based measures (CIDI and SIDP) on internalizing and externalizing mental disorders, substance use and abuse and personality disorders. In addition, we have a rich set of questionnaires, covering normal personality, alternative conceptualization of malfunctioning personality, life events, and lifestyle. The registry data include measures of education, income, employment, disability, and primary and secondary health service use. In total, questionnaire and registry data are available for 11,727 individuals and interview data are available for 2,801 twins. We will present results from these rich data. The symposium covers methodological issues such as whether governmental health registries reflect the same etiological factors as mental disorders assessed at interview. We then proceed to discuss whether different conceptualization of personality and personality disorders measure the same etiological factors, how personality disorders relate to substance use, and how substance use relates to stressful life events and psychosocial outcomes.