Psychological correlates of functional dysphonia: an investigation using the Minnesota Multiphasic Personality Inventory.

Abnormal psychological factors have been implicated in the development of functional dysphonia (FD). This investigation describes the personality and psychological characteristics of 25 female subjects who had received the diagnosis of FD. In all subjects symptoms were resolved after voice therapy. While vocally asymptomatic, these remitted subjects with FD completed the Minnesota Multiphasic Personality Inventory (MMPI), an objective personality questionnaire. When compared with a medical outpatient control group, the results showed that subjects with FD scored significantly higher on 7 of 10 clinical scales, suggesting an elevated degree of emotional maladjustment. A stepwise logistic discriminant analysis identified 2 clinical scales that provided valuable discriminatory power between the two groups. Scale 1 (Hs-hypochondriasis), which measures the number and type of reported somatic complaints, and scale 7 (Pt-psychasthenia), a measure of diffuse anxiety, discriminated the groups with 88% sensitivity and 89% specificity. The results suggested that in spite of symptom improvement after voice therapy, the subjects with FD continued to exhibit poor levels of adaptive functioning, which may represent trait-like vulnerability. The clinical implications of these results for voice practitioners are discussed.