Personality profile in essential tremor: A case-control study

Background: Neuropsychiatric findings described in essential tremor (ET) include depression and anxiety. There may be personality features as well; in 2004, we demonstrated higher harm avoidance (HA) scores in ET patients than controls. We now (1) determined whether this finding could be replicated in a new sample of cases and controls, and (2) analyzed HA sub-scores (HA1-HA4) to further understand case-control differences. Design/Methods: 60 ET cases and 35 controls were evaluated using the Tridimensional Personality Questionnaire (TPQ), which assesses three domains of personality: HA, novelty seeking (NS), and reward dependence (RD). Results: Total HA and total NS scores were marginally higher in cases than controls (14.8 ± 7.6 vs. 12.4 ± 5.3, p = 0.09) and (13.8 ± 5.4 vs. 11.8 ± 4.9, p = 0.09), respectively. When adjusted for age and gender, cases and controls differed with respect to total HA score (p = 0.03) but not total NS score (p = 0.10). Further analysis of HA sub-scores demonstrated that HA1 (anticipatory worry and pessimism) and HA4 (fatigability and asthenia) were most robustly elevated in cases vs. controls (p = 0.04 and p = 0.01, respectively). Conclusions: This study suggests that ET cases have a personality profile characterized by a greater HA, with certain domains of HA most affected. It is unclear whether this personality profile is pre-morbid or is a co-morbid feature of the illness, nor it is known whether the greater tendency towards HA in ET lessens receptivity to deep brain stimulation surgery and other therapies.