HCRTR2 and major depressive disorder: In an exploratory clinical study (Clinical trial identification number NCT02067299), the drug demonstrated a dose-dependent normalization of sleep after a single dose of 10–20 or 40 mg in MDD patients treated with SSRI or SNRI with residual insomnia (Brooks et al., 2019); the dose-dependent effect is in line with previous studies of OX2R antagonists in heathy subjects (Ark et al., 2018).