What exactly is ‘Captagon’, the drug of choice for Isis fighters?

Isis fighters in Syria have been using an amphetamine called ‘Captagon’ to stay alert in battle – a drug unknown outside the Middle East. Made out of easily available legal substances, this drug was first created in the sixties to treat hyperactivity, narcolepsy and depression but was banned in eighties for being too addictive. (metro.co.uk)