Clinical and acoustic measures of the negative syndrome

We studied 12 male schizophrenia patients in a 6-week treatment trial comparing two neuroleptics and placebo. Efficacy in regard to negative symptoms was of interest, and Alphs' Negative Symptom Assessment (NSA) was included. The NSA includes behaviorally anchored ratings such as "prolonged time to response" and "restricted speech output." Audio recordings of interviews with the patients were analyzed acoustically. In general, the behavioral anchors did not prevent the ratings from being influenced by global impressions. There was a strong correlation between each item and the total of other items, but a modest correlation with the relevant behavioral measure. Results suggest that, even with specific and behaviorally anchored items, the clinician's assessment is confounded by global impressions. Treatment effects were greater for the acoustic measures than for the clinical measures.