1) I am wondering about the direct effects nitrous oxide has on the brain, and if it is a fallacy that it kills brain cells.

2) What are the health dangers of inhaling nitrous oxide? I have heard people say that it "kills brain cells," but no one seems to know how, to what extent, and what the resulting effects are. Since nitrous oxide is commonly administered as anesthesia, is there a safe way to consume it for recreational use? If the user controls her oxygen intake, do the harmful effects (if any) still occur?

I have a friend at school who quit smoking last year in January, and went back to it in October. I have no idea why, and he also started doing other drugs, such as smoking blunts, doing ecstasy, and taking steroids. The drug that I am worried about him doing the most is ecstasy, because it's a dangerous drug. Also, he is always talking about doing drugs. How can I help him? I still want him to be my friend. Please help. This is serious.

I have smoked marijuana on and off for about a year, not ever more than about once every other week. The last two times I smoked, I experienced uncontrollable tremors in my leg. It wasn't painful like a muscle spasm, but it was uncomfortable and unsettling. Was this merely nervousness (this was the first time I had people "over" at my own suite to smoke and I was a little worried that my roommates would be angry)? Or, could this be a side effect of the drug?

Lately, I have been doing a drug called Special K. I know it is a sedative/tranquilizer (what's the difference?), but very little about side effects, etc. Also, can you go over similar information about the drug X?

I have been a smoker for about 8 years and smoke about a pack per day. I am also an alcoholic and now drink about 7 to 10 beers a day, and have been for the past 2.5 years. Last night I decided to quit drinking beer every day and today I am already shaky, nervous, and can't concentrate. I want to quit smoking also so I can join the army. Is it dangerous to quit both at once? Would it be too much stress on my body and mind? And also, would having just one beer a day for the next couple days help with the withdrawal symptoms?

I used to be a heavy ecstasy user and now am clean from ecstasy. I find I can't ejaculate. Alice, I guess my question is would the ecstasy have affected me sexually, so that I can't ejaculate when I'm having sex?

I am a teenage girl currently taking Adderall (20 mg) to treat my ADHD. My question: does taking this medication affect sexual wantings or behavior? I am supposed to start taking it at 7:00am so it will wear out at about 9:00 or 9:30pm. Since I go out later at night, my medicine is usually worn off before I engage in any kind of sexual activity. But sometimes on weekends I wake up late and have to take it at later times such as 12:00 or 1:00pm. Since then it will not wear off until after I go out, would being on Adderall affect my sexual behavior? I feel like I am less "horny" when on Adderall and sex is worse because of the lack of my desires. Does this have anything to do with my medicine or is it just a coincidence?