Longitudinal research on the entire long-stay population of a Dutch general psychiatric hospital produced three principal results. 1) Psychiatric diagnosis showed little consistency: 46% of the patients did not receive the same main diagnosis in the study s two measurement years, 1989 en 1991. 2) When age was controllerd for, patients who had stayed longer in the hospital tended to function at a higher level. 3) There are strong indications that systematic, individualized programs of care, together with an open and respectful attitude, lead patients to function at a higher level, especially in the area of social skills.