Multiple contributions to clinical presentation of flat affect in schizophrenia

Flat affect has long been recognized as a central manifestation of schizophrenia, and has more recently been appreciated as a stable and prognostically important attribute of this disorder. Yet, because it is thought to be difficult to evaluate, flat affect has been deemphasized in criterion-based diagnostic systems. Results of this study suggest that the clinical evaluation of flat affect may be contaminated by a number of behaviorally similar processes. The components we identified included right hemisphere dysfunction, retardation and extrapyramidal effects, as well as the sequelae of hospitalization. Thus, in the clinical evaluation of flat affect, a multivariate approach in which these different components are considered separately might improve the reliability of evaluation and make this important sign more useful.