I've recently been reading about ADHD and smoking. I'm barely-educated on the subject but it appears that there are some cases where Nicotine patches have shown to help regulate ADHD behavior (and some where it gets worse).
I thought about opening a thread to get peoples' opinions, but I fear it will immediately border as unqualified medical advice.
I listened to this as a podcast the other day, he goes deep into the science of nicotine, most it went over my head, but it was interesting none the less. FYI, he lumps all forms of smoking tobacco together. If you don't want to hear about the risks, don't bother, but if you want to know more about the pros and cons it will be an educational couple of hours. From the bit I could take away from it, all in all, nicotine is about as bad for you as caffeine, and I ingest a lot more caffeine than nicotine.