July 21 (IANS) A total of 6,50,000 people in Japan misused nonprescription drugs last year, with teenagers being the most affected group, according to a new study by Japan's health ministry. About 0.75 per cent of the population aged 15 to 64 used over-the-counter (OTC) medications, such as cough suppressants and painkillers, to get high, national news agency Kyodo reported, citing the findings from the latest research of the Ministry of Health, Labour and Welfare, Xinhua news agency reported. About 85,000 teenagers, or 1.46 per cent of those aged 15 to 19, abused the drugs, a rate higher than any other age group, according to the study, which offers a better understanding of the scope of drug abuse among teenagers. Takuya Shimane, a researcher at the National Center of Neurology and Psychiatry, said the outcome strongly suggests that abusive use is "centred on teenagers," reported Kyodo. The findings underscored the need to revise drug sale regulations and support those misusing medication, and the ministry is planning to restrict the sale of large quantities of addictive OTC drugs to individuals under 20. Shimane, who led the study, also stressed the importance of educating junior and senior high school students about the risks of overdose. The research, conducted between October and December through mailed questionnaires, received 3,026 valid responses from 5,000 recipients. For the first time, the questionnaire asked respondents if they had used nonprescription drugs beyond the correct dosage to alter their mood, Kyodo reported.