I am pretty certain its been debunked that cannabis would cause brain damage, in fact it actually helps protect brain cells from damage in people with epilepsy because seizures can cause brain damage. It isn't entirely understood how all it effects the brain...but studies indicate you cannot suffer a deadly overdose on it and aside from smoking it doesn't do any physical damage.

I doubt someone from out of state could order cannabis from here without getting in trouble...though there are scammers that say they can sell over the internet. People from out of state can buy some if they are in colorado, still probably illegal to take it back to their state.