Persisting positive symptoms largely unresponsive to treatment (Tuma & May, 1979; Macmillan et al, 1986; May et al, 1989) occur in about 7% of patients with schizophrenia but lesser degrees of treatment resistance are common (Hogarty, 1988; Johnstone, 1990) and problems of recurrence of positive symptoms and deterioration of negative symptoms are well known (Johnstone, 1990). Schizophrenic patients have also been found to have persisting non-psychotic symptoms, particularly depression (Cheadle et al, 1978). Disorders of movement in relation to schizophrenia and their treatment have been found to be disabling in a few patients and to cause lesser problems for many (Kane et al, 1985). The assessment of the mental state and of clinical evidence of movement disorder in the patients who form the subjects of the Harrow study was therefore clearly of interest, as it is rarely possible to examine these issues in a large, unselected sample.