Psychological Medicine

Original Articles

Cognitive deficit and the prediction of rehabilitation success in a chronic psychiatric group

Til Wykesa1 c1 and Graham Dunna1

a1 Departments of Psychology, Biostatistics and Computing, Institute of Psychiatry, London


This paper describes the second stage (years 4, 5 and 6) of a prospective follow-up of a sample of chronic patients which was designed to investigate the in service use. It also tested the relative predictive power of variables which included demographic, symptomatic and behavioural factors as well as a novel reaction time variable which reflects response processing time.

During the six years of the study 91% of the patients in the sample changed either the degree of their day and/or night care. Many moved to more independence but, a number did also become more dependent on psychiatric services. There were no differences in outcome between a schizophrenic group and patients with other diagnoses. These results suggest a level of flexibility in outcome even in a severely disabled chronic group.

The main predictor of future service use at each stage of the follow-up for the whole group was chronicity at entry to the study. But, when the group was divided into schizophrenic patients and ‘others’, the response processing measure was a significant predictor of service use in the schizophrenic group and accounted for between 17% and 30% of the variance. For the ‘other’ diagnostic group, the age of the patient seemed to be the major determinant of care.

The reaction time variable seems to be an extra class correlate of a strict diagnosis of schizophrenia. It may also be a stable or episodic vulnerability factor, but as well as these promising hypotheses, which have yet to be justified, this measure does seem to have pragmatic value in predicting outcome in a rehabilitation network.


c1 Address for correspondence: Dr Til Wykes, Department of Psychology, Institute of Psychiatry, De Crespigny Park, London SE5 8AF.