The number of under-18s being treated for cocaine addiction has risen more than 65%.
NHS figures also show the number of 18 to 24-year-olds being treated for the same addiction in the same period doubled.
Meanwhile, three-quarters of users combined the drug with alcohol, according to the study by the National Treatment Agency (NTA) in England. Mixing is thought to boost the high but causes more damage to the heart and makes users more violent.
Four in 10 addicts were clean after six months of cognitive behavioural therapy, although nearly 25% of those taking treatment dropped out.
Paul Hayes, chief executive of the NTA, said: "More people are using powder cocaine, more people are seeking help for dependency, and more are being successfully treated. Powder cocaine is a powerful stimulant drug which induces psychological rather than physical dependence.
"Most users will be treated locally in their communities with talking therapies rather than medication, and our message to users is that if they need help, they can get it and it works."
Last year 12,354 people were treated for cocaine addiction in England.