Introduction Open studies suggest that mirtazapine has efficacy in panic disorder treatment. We designed an open study that evaluates changes induced by mirtazapine compared with paroxetine in panic disorder. Methodology Patients 18-65 years old consecutively referred to a psychiatry liaison service with panic disorder (DSM-IV criteria) were offered either mirtazapine or paroxetine treatment. Results There were statistically significant reductions from baseline to week 3 and from week 3 to 8 for mirtazapine and paroxetine groups for: number of panic attacks, Beck Anxiety or Depression Inventory (BAI, BDI) Clinical Global Impresion (CGI) of panic disorder severity and CGI of panic disorder response (these variables were evaluated by the patient, the clinician or a blind evaluator). Responders at week 3 (BAI decrease of 50%) were 83% for the mirtazapine group and 84% for the paroxetine group. Responders at week 8 (number of panic attacks equal to 0) were 77% for the mirtazapine group and 73% for the paroxetine group Statistically significant differences between mirtazapine and paroxetine were found for number of panic attacks at weeks 3 and 8 and BAI at week 3, suggesting a faster response for mirtazapine. Responders at week 8 maintained a no recurrence figure of 95% at follow-up 6 months later. Panic disorder either with or without comorbid depression improved in both groups of treatment. Discussion Our study supports the hypothesis that mirtazapine has efficacy in the treatment of panic disorder either with or without comorbid depression.
Keywords: Mirtazapine; SSRI; open study; panic disorder; paroxetine.