I was put on adhd pills about 8 months ago,

Patient: I was put on adhd pills about 8 months ago, concerta. 56mg. I was having troubles sleeping so my doctor suggested melatonin. I have been taking 1-3 every night for about 8 months now, ive suddenly ran into the fact that i cant sleep anymore. My bodys tired but my minds awake, i cant fall asleep till about 12-2 in the morning and last about an hour before waking up and struggling to go back to sleep. this has been going on for about a week now, could this be a side affect to long term use of melatonin?

Symptoms: None,

Doctor: