No, I'm not advocating the benefits of taking up smoking but I did come across an interesting article in a rercent issue of 'Cosmos' magazine (#29) entitled, Why Schizophrenics Smoke (p16).
Statistics suggest over three times as many people suffering from schizophrenia smoke when compared to the population as a whole (the short article quotes work done by psychiatrist Ruth Barr at Queen's University Belfast, so I suspect the numbers are based on the UK population). It had been thought that the benenfits of nicotine were assosicated with overcoming the symptoms of smoking/nicotine withdrawal (I take this to be studies using nicotine patches to help smokers quit). Whereas this study investigated the link between the high incidence of smoking and the effect of nicotine on the symptoms of the illness and suggests it helps attention span, memory and reduces impulsive behaviour. So it may go at least part of the way to explain why so many people who suffer from schizophrenia smoke (...and help their family more understanding of their smoking...well perhaps!).