People who later develop schizophrenia have thinking and memory (or "cognitive") difficulties that disrupt their everyday functioning both early in life—long before other symptoms appear—and throughout the course of their illness. The difficulties begin at different times for different types of cognitive functions, according to the most comprehensive long-term study of these problems to date, published online September 13th in the American Journal of Psychiatry.
2010 Ruane Prizewinner for Outstanding Achievement in Child and Adolescent Psychiatric Research, Terrie Moffitt, Ph.D., of Duke University, is Associate Director of an ongoing project looking at the physical and mental health of more than 1,000 babies born at one hospital in Dunedin, New Zealand between 1972 and 1973. The Dunedin study brings participants back to the research center every few years for evaluations. In the most recent study, with participants at age 38, the researchers found that 4 percent of the children eventually developed schizophrenia. Those children were found to have declines in IQ and in a range of mental functions impacting learning, executive function and motor function (versus the children who did not develop schizophrenia and did not show such declines).
Dr. Moffitt and colleagues, including co-winner of the 2010 Ruane Prize, Avshalom Caspi, Ph.D., and NARSAD Grantees Abraham Reichenberg, Ph.D., and Richard S.E. Keefe, Ph.D. (also a member of the Foundation’s Scientific Council), report that the developmental progression of deficits in schizophrenia differed across types of mental functions, and was also unique to the children with schizophrenia in their sample. Their findings confirm the progressive nature of cognitive impairment in schizophrenia and that it starts prior to manifestation of other symptoms of the illness, reinforcing the importance of early intervention.
The researchers also say their work suggests that different types of deficits may have different underlying biological causes, which has significant implications for the development of new treatments.
2010 Outstanding Achievement Prizewinner Video: