We sought to determine whether mirtazapine is safe and well-tolerated as a 
treatment for essential tremor (ET). We studied mirtazapine in a randomized, 
double-blind, placebo-controlled, crossover study of 17 ET patients. Patients 
were started with 15 mg per day of either mirtazapine or placebo for 1 week and 
the dose was escalated weekly until the targeted dose of 45 mg per day was 
achieved. This dose was maintained for 2 weeks. Tremor was assessed at baseline 
and after 14 days of 45 mg of mirtazapine or placebo. There was a minimum 
washout period of 14 days between the two arms of the study. Tremor assessments 
included global improvement, Fahn Tolosa Marin Tremor Rating Scale, Beck 
Depression Inventory and the Parkinson's Disease Questionnaire-39. Patient 
global improvement ratings indicated that in the placebo condition 12 patients 
were unchanged and 1 patient was mildly improved. In the mirtazapine condition, 
10 patients were unchanged, 2 were moderately improved and 1 was markedly 
improved. There was no significant improvement with mirtazapine or placebo 
compared to baseline as measured by the Tremor Rating Scale. Adverse effects 
were more common in the mirtazapine group and included drowsiness, confusion, 
dry mouth, weight gain, polyuria, itching, nausea, gait and balance problems, 
blurred vision, and bad taste. We conclude that the majority of the ET patients 
do not benefit from mirtazapine. Mirtazapine has significant adverse effects and 
should be used cautiously in ET patients.