The level of disability among severely mentally ill persons is a substantial and costly burden on society as well as a burden on family members and the affected individual. In the past decade, research findings have brought new hope that the disabling aspects of severe mental problems can be significantly reduced by early interventions that bring individuals under the care of professionals using effective treatment and rehabilitation methods. A major challenge for research in the 1990s will be to provide the information necessary to improve the existing systems of care by answering two questions: