Hundreds of thousands of people in Bangladesh have become hooked on yaba - a mixture of methamphetamine and caffeine sold as cheap red or pink pills. The official response has been harsh, with hundreds of people killed in alleged incidents of "crossfire".
"I was awake for seven, eight, even 10 days at a time. I was taking yaba in the morning, the afternoon, in the evening, again late at night, and then working all night and not going to bed."