The Effect of Paroxetine on the Reduction of Migraine Frequency is Independent of Its Anxiolytic Effect

Abstract

Background and purpose: Anxiety is the most important precipitating factor of migraine attacks, and more than half of migraineurs have coexisting anxiety disorders. Paroxetine, an antidepressant, is one of the selective serotonin reuptake inhibitors (SSRIs) that has an anxiolytic effect, and is also known to be effective for migraine prophylaxis. The aim of this study was to determine the role of the anxiolytic effect of paroxetine on the prevention of migraine.

Methods: This study investigated migraineurs with a general anxiety disorder who visited the neurological clinic. The following efficacy variables were assessed at baseline and after taking paroxetine (20 for 12 weeks: headache frequency, Hamilton Anxiety Rating Scale (HAM-A), Headache Management Self-Efficacy Scale (HMSE), and Headache Disability Inventory (HDI). The correlation between the headache responsiveness to paroxetine and improvement in anxiety levels was analyzed.

Results: Twenty-four patients (aged 54.96+/-12.09 years, mean+/-SD) were included in this study. Paroxetine reduced headache frequency by 49.1% within 12 weeks (p<0.05 vs baseline). HAM-A and HMSE scores also showed an improvement, whereas there was no significant change in HDI score. The baseline HAM-A scores did not differ between paroxetine responders and nonresponders. In addition, the improvement in HAM-A score was not correlated with the reduction in headache frequency.

Conclusions: Paroxetine decreased the headache frequency and reduced anxiety levels. However, the anxiolytic effect of paroxetine was not correlated with the migraine prevention effect. These observation indicate that the anxiolytic effect of paroxetine does not contribute strongly to its prophylactic effect on migraine frequency in migraineurs with anxiety disorder.

Keywords: Anxiety disorder; Headache frequency; Migraine; Paroxetine.

Figure 1

Monthly headache frequency after paroxetine administration. Headache frequency decreased to 49.1% of the baseline level at 3 following treatment with paroxetine (^*p<0.01 vs baseline, as assessed by paired t-test). mo = months.

Figure 2

Correlation between reduction in headache frequency and Hamilton Anxiety Rating (HAM-A) score. There was no direct correlation between headache frequency and HAM-A score (Pearson's correlation coefficient=-0.196; p=0.422).