Stability and course of neuropsychological deficits in schizophrenia.
BACKGROUND
Neuropsychological deficits in schizophrenia appear to predate clinical symptoms of the disease and become more pronounced at illness onset, but controversy exists about whether and when further neuropsychological progression may occur.


OBJECTIVE
To identify and characterize any subset of patients who evidenced progressive neuropsychological impairment, we compared the longitudinal stability of neuropsychological functioning in schizophrenic outpatients and normal comparison subjects.


METHODS
One hundred forty-two schizophrenic outpatients and 206 normal comparison subjects were given annually scheduled comprehensive neuropsychological evaluations during an average of 3 years (range, 6 months to 10 years). Clinically and demographically defined subgroups were compared, and test-retest norms were used to identify individual patients who showed unusual worsening over time.


RESULTS
The schizophrenic group was neuropsychologically more impaired than the normal comparison subjects but showed comparable test-retest reliability and comparable neuropsychological stability over both short (mean, 1.6 years) and long (mean, 5 years) follow-up periods. No significant differences in neuropsychological change were found between schizophrenic subgroups defined by current age, age at onset of illness, baseline level of neuropsychological impairment, improvement or worsening of clinical symptoms, and occurrence of incident tardive dyskinesia. Norms for change also failed to show neuropsychological progression in individuals with schizophrenia.


CONCLUSIONS
Neuropsychological impairment in ambulatory persons with schizophrenia appears to remain stable, regardless of baseline characteristics and changes in clinical state. Our results may not be generalizable to the minority of institutionalized poor-outcome patients.
Heaton
R K
RK
Department of Psychiatry, University of California, San Diego, 140 Arbor Dr, San Diego, CA 92103, USA. rheaton@ucsd.edu
Gladsjo
J A
JA
Palmer
B W
BW
Kuck
J
J
Marcotte
T D
TD
Jeste
D V
DV
D000328:Adult; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D014888:Wechsler Scales / Q000706:statistics & numerical data