Psychiatric disorders in patients with essential tremor

Background: Previous studies have reported that a consistent proportion of patients with Essential Tremor may have psychiatric disorders but it is unclear whether these disorders are increased in frequency as compared to healthy subjects. Methods: In a case-control study, we adopted the structured interviews for DSM-IV, SCID-I and SCID-II, to investigate psychiatric and personality disorders in 37 ET patients and 34 healthy subjects. As cognitive changes in ET may be a confounding factor we enrolled patients and healthy control subjects without cognitive dysfunction. Results: SCID-I showed that Axis-I psychiatric disorders, mainly depressive disorders, were more frequent in ET patients (20 of 37; 54%) than in healthy subjects (8 of 34; 22%) (p < 0.01). Depressive disorders were more frequent in patients with a family history of ET (p < 0.05) in comparison to patients without a family history. SCID-II disclosed that the frequency of personality disorders was similar in patients with ET and healthy subjects. Conclusion: Psychiatric disorders may be associated to the neurological manifestations of ET.