I have smoked weed probably over a hundred times AT LEAST. The first time I did was 4 years ago and I did it sporadically until this past summer when I did it pretty much everyday. Once school started I only do it about once a week.
I have taken ritalin before, but yesterday I took Adderall XR for the first time (to study for finals).
Everyone wanted to take a study break, so we bought an eigth and decided to smoke. After about 5 deep hits, I started to laugh uncontrollably. I didn't think anything was funny, I was in PAIN from laughing so much, and the severity of my cotton mouth made it hard to breathe. I started to get this feeling (inside) that a certain combination of muscles (the same ones that tense when you laugh) were contracting which was causing me to make the motion to laugh--which was causing me to laugh. it was the scariest experience. My hear rate was EXTREMELY high and my muscle contractions were in sync with my heart rate. Everytime I started to calm down and explain what was happening I would start up laughing again. After nearly 40 minutes (yes this was timed) I finally realized that if I gripped the table my body wouldn't move (I could feel the contractions still, but nobody else could see the contractions in my body). I tried to calm down and for the next 30 min any time I started laughing it;d be hard to stop. Finally after about 2 hours I started to calm down and was able to get up (Oh, i forgot to mention that i was pretty much stuck in the position, the only ways my muscles would move were if i moved them into some sort of motion that resembled what my muscles do when I laugh, therefore I could not even stand up).
I laid down and after about 30 min fell asleep finally. when I woke up this morning, i felt perfectly normal. I looked on the internet and it looks like perhaps it was some form of Myoclonus, however, my symptoms were also similar to that of a concious seizure--that affects your muscles more so than your brain!

That makes me very nervous! Can someone PLEASE explain what happened!?! Or if you've ever experienced/seen anything similar!?