I'm not a psychiatrist, I'm a haematologist. I deal in blood and chemotherapy, not mental health, so of course my anecdotal experience is not representative: the people I saw are the poor sods who happened to have schizophrenia AND some manner of blood cancer.
Really, I said as much in my post. Mental health is NOT my field of choice. That being said... as far as I know, from when I studied this in medical school, and for what I've talked at times with psychiatrists (eg during consultations concerning the people above), they might hesitate before recommending someone with schizophrenia to stop smoking (depending on the circumstances), but they certainly did NOT recommend them to start smoking.
I was checking the current recommendations in
medscape (which is my general medicine go-to guide btw. Poor man's Up to Date insofar it's actually free, but not really any worse), and I found an interesting tidbit
Smoking tobacco products induces the liver enzyme CYP1A2 (though nicotine patches, nicotine inhalers, and chewing tobacco do not); this enzyme metabolizes a number of antipsychotic drugs, so that, for example, patients who stop smoking while being treated with clozapine or olanzapine often experience increased antipsychotic levels; a patient who has stopped smoking may have a variety of complaints, and checking drug levels can help determine their etiology
That's a strong confusing factor for smoking cessation and schizophrenia (and mind you, I think withdrawal alone is likely a strong confusing factor by itself.
Also, more relevantly: I looked up the
NICE guidelines for schizophrenia, and, sure enough, they DO NOT recommend to smoke, and they DO recommend smoking cessation.
Offer people with psychosis or schizophrenia who smoke help to stop smoking, even if previous attempts have been unsuccessful. Be aware of the potential significant impact of reducing cigarette smoking on the metabolism of other drugs, particularly clozapine and olanzapine. [new 2014]