He has published over 250 scientific papers and four books on these and related areas. As Director of the Chicago Followup Study, he has received several national awards for his research on thought disorder, psychosis, long-term adjustment, suicide, and recovery in schizophrenia. Recently his research has focused on longitudinal studies of the long-term effects of antipsychotic medications. He has been on the faculty at Yale University and the University of Chicago, and in 1990, moved to the Medical College of the University of Illinois as Professor and Director of Psychology in the Department of Psychiatry. He is now Distinguished Professor Emeritus there.