I strongly suspect there are long-term effects for anyone who would be described as a "pothead". However, there are also quite a few occasional users who you wouldn't normally think of as users, and who do not suffer apparent long-term effects. In this respect, it's fairly similar to alcohol. futureteach, I understand your revulsion, but is personal revulsion really a basis to criminalize something? After all, I could be revolted and think it is incredibly stupid for men to wear women's clothing, but I'm not going to suggest men in drag should be arrested.