monitoring should be taken. Efficacy and tolerability Mirtazapine has been found to be one of the most effective antidepressants available and has a generally tolerable side effect profile. In a major systematic review published in 2009 which compared the efficacy and tolerability of 12 popular antidepressants, mirtazapine, escitalopram (Lexapro, Cipralex), venlafaxine (Effexor),