The orexin or hypocretin system controls a broad range of physiological and psychological functions including arousal or wakefulness (España et al. 2002; reviewed in Alexandre et al. 2013); feeding (reviewed in Sakurai 1999; Muthmainah et al. 2021); reward (reviewed in Plaza-Zabala et al. 2012); energy homeostasis (reviewed in Tsuneki et al. 2012); the multi-modal stress response precipitating anxiety (reviewed in Grafe and Bhatnagar 2018); and reproduction (reviewed in Silveyra et al. 2010). This evidence concerns the gene HCRT and Anxiety.