a1 Hotchkiss Brain Institute, Department of Psychiatry, University of Calgary, Alberta, Canada
Although it is well established that cognitive impairment is a common feature of schizophrenia, only recently has cognitive functioning been prospectively studied in individuals at clinical high risk (CHR) for developing psychosis. To date, both cross-sectional and longitudinal studies have been conducted in the CHR population and in the context of later conversion to psychosis. A comprehensive review of the literature suggests that CHR individuals have general and specific baseline cognitive deficits compared to healthy controls. As a group, their cognitive course, tends to remain stable over time and in this way does not differ from healthy controls. For those who go on to develop a full-blown psychotic illness compared to those who do not convert, there appeared to be minimal differences at baseline with respect to cognition, although over time the converters may show deterioration in certain cognitive abilities compared to the non-converters. However, for many cognitive domains results are mixed, and may result from methodological limitations.
(Online publication July 30 2012)
c1 Address for correspondence: J. Addington, Centre for Mental Health Research and Education, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada. (E-mail: email@example.com)