Yes, numerous studies and tests have proven that smoking weed does damage the brain. It has also been found to cause behavior problems, like booze and other drugs do. In addition Marijuana also does permanent damage to the sperm and egg cells of the reproductive tract, and can affect ones sperm levels, as well as the ability to "perform." Like booze, it also impairs thinking and physical ability, so one is not safe behind the wheel, or operating any kind of equipment.
Unfortunately, too many people are willing to overlook the hazards of drugs and booze in order to enjoy the feelings that these things provide. Abusing these things is illegal because people under the influence are a hazard to others. Making them illegal is also done to protect young people who might, in ignorance, other wise use them.
I don't use drugs myself, except for necessary meds, because I don't want to hurt my body and mind with them, and I don't want to be hurt or killed by other drivers who are under the influence of drugs/booze. I also don't appreciate being put at risk by drivers distracted with their electronic gadgets, including phones, or who are distracted by other activities that should only be done when the car is safely parked somewhere. And no, I don't make calls or answer them when the car is rolling. If it is important, they will call back, or they can wait until I can stop somewhere and safely listen to my voice mail, and then return their call. The same goes for text messages. I don't want to get hurt or killed by mine or another's bad choices on the road, and I don't want to hurt or kill someone, either.
If you are thinking of doing this to "fit in", you need to find a better group of people to hang out with. Anyone who would pressure you into doing drugs or booze, and messing up your body, mind, and life, is not your friend. You will have better luck finding real friends if you volunteer with charitable organizations. The other volunteers are bound to be a much nicer crowd. If that's not your bag, you can try sports or join a club.
Please don't mess up your mind, body, and life with drugs and booze. It's not worth it. If you want a legal "buzz" take up exercise. Your body makes endorphins when you exercise. These are a safe, natural "drug" that boosts the mood, and won't mess up your body or your mind, and you will be healthier from all that exercise. And remember, we on the spectrum are all:
A Different Drummer
If a man does not keep pace with his companions,
Perhaps it is because he hears a different drummer.
Let him step to the music which he hears,
However measured or far away.
--Henry David Thoreau