ABSTRACT
Introduction Many reviews of Nordic registers and their uses in medical research have focused on specific topics or on only one country (Cappelen & Lyshol, 2004; Gissler & Haukka, 2004; Mortensen, 2004; Munk-Jørgensen, Kastrup, & Mortensen, 1993). We describe a range of Nordic registers that have been used in psychiatric research and discuss a number of general issues related to register-based research. We then review a selection of studies in psychiatric epidemiology arising from Denmark, Finland, Norway and Sweden that have made use of such registers, and highlight some, such as a study of the psychiatric sequelae of viral infections of the nervous system during childhood, that we feel epitomize the scope for opportunistic research in this context.
