New Delhi, Oct. 12 -- ONE PEPTIDE has recently transformed medicine. Drugs based on glucagon-like peptide-1 (GLP-1), a hormone released by the gut after a meal, began as treatments for diabetes before proving remarkably good at helping people shed weight. They have since shown benefits in the fields of heart disease, kidney disease, sleep apnoea and other ailments. Drugmakers are now betting that two other peptides, the orexins, could follow a similar path for a variety of brain-related ailments.

Orexins are a pair of neurotransmitters-chemicals that carry messages between neurons. One of the main jobs of these particular neurotransmitters is to regulate wakefulness. And a new generation of drugs designed to mimic their effects is approa...