The clinical relevance of an auditory attention task (PAT) in a longitudinal study of chronic schizophrenia, with placebo substitution for chlorpromazine.

A new auditory attention task (PAT) is described. The test comprises four different subtest combinations (diotic/dichotic, slow/fast) each of 5 min duration. Omission and commission errors are combined by an index of errors (IE). The PAT was given fortnightly to 20 chronic schizophrenic inpatients for more than one year. Independent psychiatrists rated the patients according to the Brief Psychiatric Rating Scale and a Global Rating Scale. All measures yielded significant test-retest reliabilities. The patients were stabilized on individualized doses of chlorpromazine (CPZ) and randomized to two groups. Placebo was substituted for CPZ during 10 weeks, according to a double-blind cross-over design. Significant deterioration under placebo was detected by all three methods, but the PAT was the most sensitive to change. The PAT mean score (M IE) was correlated with both rating scales. Unlike the rating scales, it also correctly ordered the twenty patients along a dimension which measured the severity of illness and 'predicted' hospital discharge.