Two-year follow-up of the patients included in the WHO International Pilot Study of Schizophrenia.

Over 90% of the 1202 patients investigated in the 9 centres collaborating in the International Pilot Study of Schizophrenia were traced 2 years after the initial examination and on the average over 75% of them were re-examined, using standardized instruments and methods. Results indicate that patients diagnosed as schizophrenic on the basis of standardized assessments and clearly specified diagnostic criteria demonstrated very marked variations of course and outcome over a 2-year period. Schizophrenic patients in the centres in developing countries had considerably better course and outcome than schizophrenic patients in the centres in developed countries.