Evercore ISI analyst Umer Raffat recently called orexin a “red hot neuropsychiatry target,” and the recent Sleep 2024 meeting in Houston bolstered such a view. Also known as hypocretin, the neuropeptide orexin is known to play a crucial role in regulating wakefulness, arousal, and appetite. It’s made in the hypothalamus, and was discovered in the late 1990s. Investigators found that people with narcolepsy can show a deficiency of orexin due to the loss of neurons.