ST. LOUIS, July 5 -- For years, veterans in the waiting rooms of clinics across the country were handed two separate problems: a prescription for their weight, and a referral to addiction counseling they often could not reach. A growing body of research now suggests the first prescription may have been quietly addressing both.

A landmark study of 606,434 U.S. veterans with type 2 diabetes, published in March in The BMJ, found that those prescribed GLP-1 receptor agonists, including semaglutide-based medications sold under brand names Ozempic and Wegovy, were significantly less likely to develop a substance use disorder or, if they already had one, to overdose, be hospitalized, or die from it. Overdose events fell by 40 percent among user...