Stuttering: Neuropsychiatric features measured by content analysis of speech and the effect of risperidone on stuttering severity

Positron-emission tomographic (PET) studies and genetic research of stutter ing have recently revealed underlying cerebral neurobiologic contributing f actors in this disorder. We aimed to assess whether cognitive impairment an d other neuropsychiatric dimensions could be detected through computerized content analysis of short samples of speech from stutterers, and whether ad ministration of risperidone in a double-blind placebo-controlled study coul d decrease the severity of stuttering, as well as any of the neuropsychiatr ic features of these stutterers. A group of 21 stutterers with the developm ental form of stuttering, an onset before age of 6 years, aged 20 to 74 yea rs, and who were otherwise free of: major medical or psychiatric problems, initially gave a B-minute tape-recorded speech sample in response to purpos ely ambiguous instructions to talk about any interesting or dramatic life e xperiences. Then, half of these subjects (n = 11) were randomly selected to receive 6 weeks of risperidone treatment up to 2.0 mg/d and the other half (n = 11) were administered a placebo. Both groups of subjects gave a secon d verbal sample after 6 weeks of treatment. Significantly elevated cognitiv e impairment and social alienation-personal disorganization scores, derived from the computerized content of the initial 5-minute speech samples, were found. After 6 weeks, the risperidone group improved significantly on a me asure of severity of stuttering but did not improve on the percentage of ti me spent stuttering. The placebo group did not improve on either measure of stuttering. The psychopathological processes of subjects who received risp eridone treatment, including those with elevated cognitive impairment and s ocial alienation-personal disorganization, did not change significantly. Ho wever, stutterers who had lower scores on Verbal content analysis-derived s hame anxiety guilt anxiety, or hostility inward measures improved significa ntly more with risperidone than stutterers with higher scores on these meas ures. The findings of elevated cognitive impairment and social alienation-p ersonal disorganization scores of adult stutterers with the early developme ntal form of stuttering are consistent with the neurobiologic abnormalities found in PET-scan and genetic research involving stutterers. Risperidone ( less than or equal to 2.0 mg/d) can reduce the severity of stuttering while not significantly affecting the magnitude of neuropsychiatric dimensions s uch as cognitive impairment or social alienation-personal disorganization. The less the inward shame, guilt, or hostility of the stutterers, the bette r the beneficial effect of risperidone on the severity of stuttering. Copyr ight (C) 1999 by W.B. Saunders Company.