My son is ADHD and was having alot of trouble sleping at night and was prescribed clonidine. It had not affect on him and he continued to wake up and wander during the night. I discovered that this medication is a blood pressure medication and our pediatrician was not monitoring him while he was on this. We also have tried the melatonin and he was up to 3mg a night and it had no affect.
Our doctor had us try 1 mg of melatonin and it works well. Natural, so no side affects, we have had to increase to 2 mg on occassion, but it doesn't knock him out like the clonidine did. Maybe you could try that?