India, Nov. 4 -- The face of addiction has changed in metro cities, and most families haven't caught up with what it actually looks like now. Five years ago, rehabilitation centres across Mumbai, Delhi, and Bangalore were treating mostly men in their forties and fifties. That picture has shifted. Walk into any urban psychiatrist's clinic today and a significant chunk of the caseload is under thirty. Some haven't even finished college.

These aren't the cases families brace for. There's no dramatic downward spiral. No job loss. No public incident. The person is working, socialising, splitting bills, keeping up appearances. The dependency runs underneath all of it, invisible to everyone except maybe the person themselves. Sometimes not even...