Melatonin Or Not ??

Hi everyone, 

Advice needed please, 

Right my little man is 2 and half years old. With suspected Autism and ADHD ? We are on the list for a MDA and currently receiving support from the child development centre.

So one massive issue is sleep, we can get him in a semi ok routine still going to sleep far too late then anything from routine appoitment at Great Ormond st hosp, or a day out, illness, attempted family holiday will throw him off course, so the most recent is whats done it this time.

But it lasts for months currently going into third month where he isnt falling to sleep till between 10.30/12.30 waking every 3-4 hours.  He has always woke a lot and demands with agression to come doen stairs to eat, drink watch tv act like its 9 am basically. 

So as this has been the case on and off since he was a baby, his pead at child deveolpment centre and his behaviour/play theripst is suggesting Melatonin ?  

But I have read some scary reviews on it? making kids agressive >? and my little man is already very agressive   and that if there are sleep issues there is a deeper issue and the Melatonin just hides it. and more in depth investigations should be done?? 

ANy advice welcome, any one use it for there little ones?> any one taken a different to sort sleep issues.

Thanks 

Stacey