Differential diagnosis of stuttering for forensic purposes.

PURPOSE: This case study demonstrates the application of an assessment protocol for differential diagnosis of psychogenic stuttering, neurogenic stuttering, developmental stuttering, and malingering.

METHOD: A male in his late 30s, accused of armed robbery, was evaluated for stuttering at the request of his defense attorney. The speech assessment included 4 main sections: collection of speech samples, observation in multiple speaking conditions, evaluation of communication attitudes, and consideration of case history and background information.

RESULTS

The defendant stuttered severely in all speaking conditions. He demonstrated typical stuttering loci and consistency, but no adaptation. Communication attitudes were typical of people who stutter, but steady, direct eye contact was atypical. His statements about his speech conflicted with reports of outside witnesses.

CONCLUSIONS

Characteristics were consistent with developmental stuttering and partial malingering. Both psychogenic and neurogenic forms of stuttering were suspected, but mixed results were largely unsupportive. Valuable protocol elements included speech sampling under multiple speaking conditions, careful examination of case history information, and indirect tests of malingering. Further knowledge and research are warranted to improve processes of differential diagnoses among subtypes of developmental, psychogenic, and neurogenic forms of stuttering as well as malingering.