Is there a specific psychiatric background or personality profile in functional dystonia?

The aim of this cross-sectional study was to identify if there was a specific difference between patients with functional dystonia (DysF) and those with adult-onset, isolated idiopathic ("primary") dystonia (DysP) in terms of psychiatric disorders, psychological stressor, dissociation correlates, and personality traits.

Thirty-nine clinically definite DysF and 30 DysP patients matched by age, gender and dystonia distribution underwent psychiatric interview based on DSM-5 criteria and additional testings for global cognitive and psychiatric functions (Mini-Mental State Examination, Hamilton Depression and Hamilton Anxiety Rating Scale, Apathy Scale, Somatoform Dissociation Questionnaire-20, Dissociative Experiences Scale II, and the five-dimensional Revised Neuroticism-Extroversion-Openness Personality Inventory).

Almost half of our DysF patients had prior psychiatric treatment, which was significantly more frequent when compared to DysP. Patients with DysF in comparison to DysP also had considerably more frequent preceding stress, higher apathy, dissociative and somatoform scores, as well as significantly higher rate of la belle indifférence sign. This sign, stress before dystonia and prior psychiatric disorder independently predicted having DysF. Some of psychiatric disorders (i.e. substance-related disorders, schizophrenia, adjustment disorder, borderline personality disorder, post-traumatic stress disorder, psychotic depression, delusional disorder) were exclusively present among DysF patients. DysF compared to DysP patients had lower scores for both extroversion and openness to experiences.

Our data found different pattern of psychiatric comorbidity and personality traits between DysF and DysP patients, including a higher prevalence of psychological stressor and dissociative correlates, indicating at least a partial role of psychological mechanisms in the pathogenesis of DysF.