Lamictal for anxiety/dysregulation

Hi there, I’m looking to learn about autistic kids taking Lamictal for emotional regulation, stress, anxiety. My son is on an ssri, but needs more help for the ruminating ocd anxiety questions. We do ALL the natural therapies and techniques. Can anyone share what it’s like during the first few days of children taking Lamictal? Side effects? How long it takes to notice if it is or isn’t working? Dosing for kids under 10.

I’m aware of the rash to look out for but when I start him I want to know what to look for mood wise if he’s having a bad reaction or if it’s helping. TIA