Neuropsychological performance over time in people at high risk of developing schizophrenia and controls.
BACKGROUND
Neuropsychological assessments of relatives of schizophrenics have shown subtle impairments in verbal memory, executive and intellectual function, which are stable in those beyond the age of maximum risk for the disorder. We sought to: (1) determine baseline neurocognitive predictors of psychosis, and (2) compare performance over time between relatives within the age of maximum risk, and controls.


METHODS
(1) and (2) were examined in 118 individuals at familial high risk of schizophrenia (HR) and 30 controls (C), using one-way analyses of variance (ANOVAs) and repeated measures analyses of covariance (ANCOVAs), controlling for intelligence quotient, time between and number of assessments, and correcting for multiple comparisons.


RESULTS
HR who became ill (n = 13) performed nonsignificantly less well at baseline than HR who did not (n = 105) on a test of verbal learning (t(109) = 2.1, p = .03). Across assessments, C performed significantly better than the entire HR group on immediate (F(3,133) = 5.11, p = .002) and delayed (F(3,133) = 5.02, p = .002) story recall. There were no significant interactions of time by group.


CONCLUSIONS
Results suggest greater verbal memory impairment in HR who go on to develop schizophrenia. Stable differences between groups over time suggest a trait deficit, which is relatively unaffected by the presence of psychotic symptoms and psychosis onset. Alternatively, small numbers may have precluded detection of group by time interactions.
Whyte
Marie-Claire
MC
Division of Psychiatry, University of Edinburgh, Morningside Park, Edinburgh, United Kingdom.
Brett
Caroline
C
Harrison
Lesley K
LK
Byrne
Majella
M
Miller
Patrick
P
Lawrie
Stephen M
SM
Johnstone
Eve C
EC
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007360:Intelligence / Q000502:physiology; D007361:Intelligence Tests / Q000706:statistics & numerical data; D008297:Male; D008568:Memory / Q000502:physiology; D008609:Mental Status Schedule; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011594:Psychometrics; D012189:Retrospective Studies; D012306:Risk; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013997:Time Factors; D014706:Verbal Learning / Q000502:physiology