when I worked on K Street in DC, and used a doctor in the building who treated a lot of high-profile print and television journalists, doc told me that almost all of them were heavy tobacco users who had a hard time giving it up, because it helped them to write and to concentrate.
I’m not suggesting tobacco as a ‘good idea’ for those who write and want to concentrate; but there is definitely a difference between the effects of tobacco v. MJ on the brain and intellect.
From what I’ve read, 90% of bipolar disordered people smoke as they use tobacco to regulate their brain. It stimulates when they’re down and calms when their manic. It seems fairly apparent to me that if bipolars are able to utilize it to self-medicate, it obviously does something beneficial. Unfortunately the benefits are far outweighed by the damage to the body that it entails with long term use.