Anecdotally as an adult with autism and not epilepsy, I was prescribed lamotrigine for mood stabilization in conjuction with antidepressants. My mood was more even(antidepressants chopped the bottoms off the lows, but everything was still a neurlogical roller coaster; lamotrigine addition turned it into a kiddy coaster with smaller valleys and shorter peaks instead of a thrill seeker's death trap) so it worked for that... But it did nothing at all for autism symptoms, no.