TAAR1 and major depressive disorder: Recent preclinical investigations have indicated that TAAR1 may play a pivotal role in a variety of psychiatric disorders, including schizophrenia, sleep disturbances, drug addiction, and stress-related disorders such as depression, bipolar disorder, and anxiety (Gainetdinov et al., 2018; Liu et al., 2024; Rantala et al., 2021; Maercker et al., 2022; Berry et al., 2017; Liu et al., 2022; Revel et al., 2011; Revel et al., 2013; Black et al., 2017; Goonawardena et al., 2019).