I personally was addicted to synth cannabinoids for about three months 8 years ago. I never had a seizure, or a stroke, and very very little bad experiences. Though I was prescribed Ativan at the time, and one time I let a guy take four hits of f a bowl I was smoking, and he looked like he was dieting. His eyes got super wide, and he tried to get up only to fall over, that repeated a number of times, I had to pretty much carry him home. I would smoke it 24/7, and just a out ev Ray night, I would puke violently, and have violent diarrhea(not simultaneously, thank god) and the withdrawals were similar to opiate withdrawals, or dxm withdrawals. But it felt AWESOME, I would have a smile stuck to my face most of the time, like I would not be able not to smile, and I would nod off on it, and have a great buzz. The main difference between synths and regular thc is thc is a partial agonist, while most synths are full agonists, that makes a big difference