Cerebrovascular reactivity following administration of mirtazapine in healthy probands--a randomized, placebo controlled double-blind clinical study

INTRODUCTION: Cerebrovascular reactivity (CVR) reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus and is important for maintaining constant cerebral blood flow. A reduced CVR increases the risk of stroke. We recently found that CVR was reduced in patients with depression. This might contribute to the higher risk of stroke that has been found in subjects suffering from depression. The characterization of pathophysiological conditions in the cerebral circulation requires the knowledge of influencing factors on CVR. We therefore investigated the influence that antidepressant administration might have on CVR in humans. METHODS: We investigated CVR in 48 healthy men before and after a 10-day application of either mirtazapine or placebo. CVR was determined by calculating the increase in cerebral blood flow velocity after stimulation with acetazolamide. Blood flow velocities were measured by transcranial Doppler ultrasound. RESULTS: There was no significant group-difference of CVR after the treatment trial compared to baseline. DISCUSSION: Mirtazapine does not seem to have an influence on CVR, or any impact on CVR might have been quickly limited by a cerebral autoregulatory response.