Neuropsychiatric, stress-related symptoms and essential tremor clinical variability

Essential tremor (ET) is characterized by marked clinical variability, possibly influenced by factors such as neuropsychiatric comorbidities that elevate stress levels. Psychological stress frequently exacerbates tremor severity, establishing a feedback loop that intensifies functional impairments and social consequences, ultimately increasing the overall disease burden. Here we aim to examine the relationship between neuropsychiatric disorders and stress-related symptoms on tremor variability in ET patients. Forty-seven ET patients underwent neurological and psychiatric assessments, including standardized scales. Data were analyzed with non-parametric tests, and Spearman's correlation was used to explore relationships between demographics and clinical measures. Concomitant psychiatric disorders (also including mood and personality disorders) were identified in 23 out of 47 patients (48.9%). Patients showed elevated levels of perceived stress. Insomnia, reported by 20 patients (42.6%), was significantly associated with increased tremor severity, as reflected in total tremor scores and measures related to activities of daily living (P values < 0.001). No other significant correlations were observed between clinical or demographic variables. In ET, we observed a high frequency of neuropsychiatric disorders and elevated stress levels. Tremor severity was associated with insomnia although it did not correlate with stress or psychiatric symptoms. This finding may reflect shared mechanisms between tremor and sleep disturbances in ET, possibly involving the locus coeruleus.