On the boundaries of blunt affect/alogia across severe mental illness: implications for Research Domain Criteria.

There is growing awareness that reduced expressive behaviors (e.g., blunt affect, alogia, psychomotor retardation) are characteristic of a range of psychiatric conditions, including mood and schizophrenia-spectrum disorders. From a Research Domain Criteria (RDoC) perspective, it would be critical to determine whether these symptoms manifest similarly across diagnostic groups--as they may share common pathophysiological underpinnings. The present study employed computerized acoustic analysis of speech produced in reaction to a range of visual stimuli in 48 stable outpatients with schizophrenia and mood disorders to offer preliminary understanding of this issue. Speaking assessments were administered 1 week-apart to examine how temporal stability might vary as a function of clinical diagnosis and symptom severity. Speech characteristics generally did not differ between groups and were similarly, and for the most part, highly stable over time. Aspects of speech were significantly associated with severity of psychosis and negative symptoms, but not with clinical depression/anxiety severity. Moreover, stability of speech characteristics generally did not vary as a function of diagnostic group or clinical severity. The magnitudes of group differences were almost exclusively in the negligible to small range. Speech production was associated with social functioning deficits. In sum, these preliminary data suggest that speech variables tap a stable and clinically important facet of psychopathology that cut across diagnostic categories. Computerized acoustic analysis of speech appears to be a promising method for understanding the pathological manifestation of these variables.