Study Methodology

Isos is a follow-up study on the course of illness and outcomes of a subset of subjects who had been in previous WHO-coordinated research studies of schizophrenia— the International Pilot Study of Schizophrenia (IPSS), the study on the Determinants of Outcome of Severe Mental Disorders (DOSMeD), and the study on Reduction and Assessment of Psychiatric Disability (RAPyD or Disability)—and additionally, subjects who had been in studies conducted locally at three other centers (Retrospective Analysis or Invited). Throughout this volume, these four distinct long-term follow-up cohorts (IPSS, DOSMeD, RAPyD, and Retrospective Analysis) are referred to as the “subsamples” of ISoS.