Of the 1,769 patients in ongoing treatment during a one-year period, 554 (31 percent) were lost to follow-up. Among a random sample of 102 patients who left treatment, two had died and 47 were interviewed. Compared with patients who left treatment, patients who stayed were older, more likely to have schizophrenia, less likely to be married, more likely to be living in an institution, more satisfied with their relationships with friends and family, and less likely to have legal problems. Average outcomes improved both for patients who stayed and for patients who left. Patients who left and could be located for follow-up were less severely ill and showed the greatest improvement and the best outcomes. Patients who left and could not be located may have been more severely ill at baseline