Decisional capacity for informed consent in schizophrenia research.

BACKGROUND: The adequacy of subjects' informed consent to research is the focus of an important public and professional debate. The potential impairment of decisional capacity in persons with schizophrenia is central to the discussions. This study ascertains the decisional capacity for informed consent in schizophrenic research subjects, to determine if reduced capacity relates to specific aspects of psychopathologic features and to test the hypothesis that reduced capacity can be remediated with an educational informed consent process. METHODS: Decisional capacity was assessed for 30 research subjects with schizophrenia and 24 nonill (normal) comparison subjects. Measures of psychopathologic features and cognition were obtained for the subjects with schizophrenia. Subjects who performed poorly on the decisional capacity measure received an educational intervention designed to improve their ability to provide informed consent and were then retested. RESULTS: The patient group did not perform as well as the controls on initial decisional capacity assessment. Poor performance was modestly related to the extent of symptoms but robustly related to cognitive impairments. Following the educational intervention, the performance of subjects with schizophrenia was equal to that of the nonill comparison group. CONCLUSIONS: Many persons with schizophrenia may be challenged by the cognitive demands of an informed consent process for research participation. In many cases, their reduced capacity can be compensated by a more intensive educational intervention as part of the informed consent process.

Effects of contextual processing on visual conditional associative learning in schizophrenia.

BACKGROUND: We adapted visual conditional associative learning paradigms to assess the contextual processing deficit model of schizophrenic cognitive impairment proposed by J.D. Cohen and D. Servan-Schreiber in 1992. In this task subjects learn the associations between four sets of stimuli through the use of feedback. We administered two experimental conditional associative learning conditions: in one, the eight stimuli used to make four pairs were all different; in the other, the pairs were made from different combinations of four identical stimuli, requiring the use of contextual information to mediate correct performance. Two additional associative learning tasks were administered where subjects generated the stimulus pairings or observed the experimenter form the pairs, eliminating the need to learn from feedback. METHODS: We tested 37 patients with schizophrenia and 20 healthy control subjects in each conditional associative learning task condition. RESULTS: Patients demonstrated significant impairments on all four conditional associative learning tasks. The demand to process contextual information did not differentially impact patient performance. Patients were better able to learn associations if they generated or observed the pairings rather than utilized feedback to guide learning. CONCLUSIONS: Patients with schizophrenia demonstrate pronounced deficits in the ability to utilize feedback to guide learning. We found no evidence of an additional deficit in processing of contextual information.

Repeatable battery for the assessment of neuropsychological status as a screening test in schizophrenia I: sensitivity, reliability, and validity.

OBJECTIVE: Cognitive impairment is an important feature of schizophrenia and is correlated with functional outcome. However, psychiatry lacks a screening instrument that can reliably assess the types of cognitive impairment often seen in schizophrenia. The authors assessed the sensitivity, convergent validity, and reliability of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as well as the relationship of the RBANS to symptoms and employment status. This newly published test takes 25 minutes to administer and was standardized on a U.S.-Census-matched adult population. The test provides a total score and five index scores, each with a mean value of 100 (SD = 15). METHOD: RBANS data were obtained from 129 patients with schizophrenia in the outpatient and inpatient programs of the Maryland Psychiatric Research Center. RBANS data were correlated with WAIS-III and Wechsler Memory Scale, 3rd ed. performance in 38 patients. Reliability data for alternate forms of the RBANS were obtained from 53 patients; symptom ratings were obtained from 48 patients; and employment status was examined in 77 patients. RESULTS: The patients with schizophrenia demonstrated marked impairment on the RBANS (their mean total score was 71.4). The patients' index scores suggested that they had relatively less impairment of language and visual functions than of memory and attention. The RBANS demonstrated high correlations with full-scale IQ and memory measures. The total score demonstrated good reliability. RBANS performance minimally correlated with Brief Psychiatric Rating Scale ratings but was strongly related to employment outcome. CONCLUSIONS: The RBANS appears to be a useful cognitive screening instrument in schizophrenia. The instrument may be a useful prognostic indicator and offers a means of assessing cognitive status.