ACHE and major depressive disorder: Therefore, this work reports the standardization of the depression model in adult zebrafish (aZF), in addition to evaluating the antidepressant effect of <i>Lippia grata</i> essential oil (EOLg) and the phytoceutical thymol, as well as their potential neuromodulatory mechanisms and <i>in vitro</i> antioxidant and anticholinesterase (AChE) activities.