Background: Primary focal dystonia (PFD) is characterized by motor symptoms. Frequent co-occurrence of abnormal mental conditions has been mentioned for decades but is less well defined. We evaluated prevalence rates of psychiatric disorders, personality disorders and traits in a large cohort of PFD patients.
Methods: Prevalence rates of clinical psychiatric diagnoses in 86 PFD patients were compared to a population-based sample (N=3943) using a multiple regression approach. Furthermore, participants were evaluated for personality disorders with the Five Factor Personality Inventory.
Results: Lifetime prevalence for any psychiatric or personality disorder was 70.9%. More specifically, axis I disorders occurred at a 4.5-fold increased chance. Highest odds ratios were found for social phobia (OR 21.6), agoraphobia (OR 16.7) and panic disorder (OR 11.5). We further found an increased prevalence rate of 32.6% for anxious personality disorders comprising obsessive-compulsive (22.1%) and avoidant personality disorders (16.3%). Except for social phobia, psychiatric disorders manifested prior to the occurrence of dystonia symptoms. In the self-rating of personality traits, PFD patients demonstrated pronounced agreeableness, conscientiousness, and reduced openness.
Conclusions: Patients with PFD show distinct neuropsychiatric and personality profiles of the anxiety spectrum. PFD should therefore be viewed as a neuropsychiatric disorder rather than a pure movement disorder.