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

Effects of escitalopram 10-20 mg/day and mirtazapine 30-45 mg/day on verbal memory of 18 healthy participants were assessed in a randomized, double-blind, placebo-controlled, three-way crossover trial.

Each treatment period lasted for 15 days and was separated from the next period by a washout period of at least 13 days. Participants received an evening dose of escitalopram 10 mg, mirtazapine 30 mg, or placebo from days 1 to 7 and an evening dose of escitalopram 20 mg, mirtazapine 45 mg, or placebo from days 8 to 15. On days 2, 9, and 16 a visual verbal memory task was performed measuring drug effects during the acute phase, after dose increase and at steady state.

Escitalopram did not affect immediate or delayed verbal memory score throughout treatment. During mirtazapine treatment, participants performed less well in the overall immediate recall score compared to placebo. This impairment was most pronounced in the final trial of the visual verbal learning task.

Verbal memory was not affected by acute and subchronic escitalopram treatment in healthy participants. Overall immediate verbal memory was slightly but significantly impaired throughout mirtazapine treatment, probably due to a general reduction in overall arousal caused by H1 blockade.