Comments on the long-term outcome of schizophrenia.

Among the many technical issues dealt with in this symposium, two clinical problems are preeminent--how is schizophrenia defined and what is meant by outcome? Each problem is highly complex. Even given adequate designs, sampling, and analysis, the generalizability of the results depends on the extent to which the diagnostic and outcome criteria are independent of each other and reproducible. The authors amply demonstrate how far we are from achieving such comparability. Schizophrenia, at the moment, is diagnosable only on its manifestations, which can be influenced for better or worse by environmental conditions. Several standardized diagnostic systems are available but they recommend different sets of rules. It is premature, therefore, to speak of a "natural" long-term course. It is even doubtful whether further long-term studies (except perhaps of birth cohorts) should be attempted until more discriminating and reliable methods have been found. Short-term studies, however, focused on specific hypotheses, still hold out promise of yielding fruitful results.