Decision-making capacity for research participation among individuals in the CATIE schizophrenia trial.
OBJECTIVE
Uncertainty regarding the degree to which persons with schizophrenia may lack decision-making capacity, and what the predictors of capacity may be led us to examine the relationship between psychopathology, neurocognitive functioning, and decision-making capacity in a large sample of persons with schizophrenia at entry into a clinical trial.


METHODS
In the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia trial, a clinical trial sponsored by the National Institute of Mental Health designed to compare the effectiveness of antipsychotic drugs, subjects were administered the MacArthur Competence Assessment Tool-Clinical Research (MacCAT-CR) and had to demonstrate adequate decision-making capacity before randomization. The MacCAT-CR, the Positive and Negative Syndrome Scale (PANSS), and an extensive neurocognitive battery were completed for 1447 study participants.


RESULTS
The neurocognitive composite score and all 5 neurocognitive subscores (verbal memory, vigilance, processing speed, reasoning, and working memory) were positive correlates of the MacCAT-CR understanding, appreciation, and reasoning scales at baseline. Higher levels of negative symptoms, but not positive symptoms, were inversely correlated with these three MacCAT-CR scales. Linear regression models of all three MacCAT-CR scales identified working memory as a predictor; negative symptoms made a small contribution to the understanding and appreciation scores.


CONCLUSIONS
Negative symptoms and aspects of neurocognitive functioning were correlated with decision-making capacity in this large sample of moderately ill subjects with schizophrenia. In multiple regression models predicting performance on the MacCAT-CR scales, working memory was the only consistent predictor of the components of decision-making capacity. Individuals with schizophrenia who have prominent cognitive dysfunction, especially memory impairment, may warrant particular attention when participating in research.
Stroup
Scott
S
Department of Psychiatry, University of North Carolina at Chapel Hill, CB# 7160, Chapel Hill, NC 27599-7160, USA. sstroup@med.unc.edu
Appelbaum
Paul
P
Swartz
Marvin
M
Patel
Mukesh
M
Davis
Sonia
S
Jeste
Dilip
D
Kim
Scott
S
Keefe
Richard
R
Manschreck
Theo
T
McEvoy
Joseph
J
Lieberman
Jeffrey
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D003430:Cross-Sectional Studies; D003657:Decision Making; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D012720:Severity of Illness Index
D014150:Antipsychotic Agents