India, July 28 -- Over one-fifth of teenagers in India may be at moderate-to-high risk of substance use, according to a study of more than 6,000 adolescents across 108 schools in six districts.

Published in The Lancet Regional Health-Southeast Asia, the study found that 21.4 per cent of adolescents were at moderate or high risk of substance use, with 10.3 per cent at moderate risk and 11.1 per cent at high risk. The remaining 78.6 per cent were classified as low risk.

The study was conducted in government and private schools across Gorakhpur in Uttar Pradesh, Kamrup in Assam, Nagpur in Maharashtra, Rajkot in Gujarat, Deoghar in Jharkhand and Puducherry.

Schools in Guwahati and Deoghar had the highest proportions of adolescents in the h...