Verbal memory performance during subchronic challenge with a selective serotonergic and a mixed action antidepressant

Area of Science:

• Neuroscience
• Psychopharmacology

Background:

• Selective serotonin reuptake inhibitors (SSRIs) like escitalopram and noradrenergic and specific serotonergic antidepressants (NaSSAs) like mirtazapine are commonly prescribed for depression.
• Their effects on cognitive functions, particularly verbal memory in healthy individuals, require thorough investigation.

Purpose of the Study:

• To evaluate the impact of escitalopram and mirtazapine on verbal memory in healthy participants.
• To compare the effects of acute and subchronic doses of these antidepressants against a placebo.

Main Methods:

• A randomized, double-blind, placebo-controlled, three-way crossover trial involving 18 healthy participants.
• Participants received escitalopram (10-20 mg/day), mirtazapine (30-45 mg/day), or placebo for 15-day periods separated by washout.
• Verbal memory was assessed using a visual verbal memory task on days 2, 9, and 16.

Main Results:

• Escitalopram treatment showed no significant effect on immediate or delayed verbal memory scores.
• Mirtazapine treatment resulted in a slight but significant impairment in the overall immediate recall score compared to placebo.
• This verbal memory impairment with mirtazapine was most evident in the final assessment of the visual verbal learning task.

Conclusions:

• Acute and subchronic escitalopram treatment does not appear to affect verbal memory in healthy individuals.
• Mirtazapine may cause a mild impairment in immediate verbal memory, potentially linked to its H1 receptor blockade and subsequent reduction in overall arousal.