Personality and voice disorders: a multitrait-multidisorder analysis.

To examine whether personality has causal, concomitant, or outcome status in common voice disorders, a vocally normal control group and 4 groups with voice disorders--functional dysphonia (FD), vocal nodules (VN), spasmodic dysphonia (SD), and unilateral vocal fold paralysis (UVFP)--were compared using the Multidimensional Personality Questionnaire (MPQ). Univariate and discriminant analyses confirmed that the FD and VN groups differed significantly from each other, the controls, and the other voice-disordered groups at both a superfactor and lower-trait level of personality description. The FD group was introverted, stress reactive, alienated, and unhappy. The VN group was described as socially dominant, stress reactive, aggressive, and impulsive. Comparisons involving the SD, UVFP, and the control subjects did not identify consistent personality differences. While group trends supported the central tenets of a trait theory outlining the dispositional bases of FD and VN, further research is needed to elucidate the specific causal mechanism(s) in individual cases. The disability hypothesis, which suggests that personality features represent the negative effects of vocal disability, was not strongly supported.