India, Aug. 8 -- In the back alleys of Delhi or inside a government-run Jan Aushadhi Kendras, a quiet drug crisis is unfolding. The substance in question isn't heroin or cocaine - it's Pregabalin, a prescription medication meant to treat anxiety, epilepsy, and nerve pain.

But on Delhi's streets, it has earned a far more sinister reputation: the "trance drug."

"I used to take it just once a week for the high," said a 28-year-old who began using Pregabalin recreationally after friends introduced him to its effects. "Soon I couldn't stop. Now I take it almost every day. And I've never once been asked for a prescription."

Pregabalin, marketed under brand names such as Lyrica, Alzain, and Axalid, is meant to be dispensed only with a doctor'...