Smoking’s Ties to Schizophrenia

Dirk Hanson
May 2, 2012

For mental health workers, it is well known that an overwhelming majority of psychiatric patients diagnosed with schizophrenia are heavy cigarette smokers. Surveys have shown that at least 60 percent of patients exhibiting symptoms of schizophrenia are smokers, compared with a national average that hovers just above 20 percent. Writing in the New England Journal of Medicine, researcher Judith J. Prochaska, associate professor of psychiatry at the University of California in San Francisco, found that “smokers with serious mental illnesses are dying 25 years sooner, on average, than Americans overall.” [i] And tobacco is one of the reasons why.

Cigarettes, long familiar in institutional settings as a tool for reinforcing wanted behavior, are slowly disappearing from state hospitals. “For state inpatient psychiatric facilities responding to surveys,” says Prochaska, “the best estimate is that about half have adopted smoke-free policies.” Increasingly, acute nicotine withdrawal is a strong part of the mix for the recently admitted smoker with schizophrenia.

An earlier study by Prochaska and colleagues, published in Psychiatric Services, found that while 42 percent of psychiatric patients at a smoke-free San Francisco hospital were smokers, averaging slightly more than a pack per day, none of the smokers received a diagnosis of dependence or withdrawal, and none were offered treatment planning for smoking cessation.[ii] “Smokers who were not given a prescription for nicotine replacement therapy were more than twice as likely to be discharged from the hospital against medical advice as nonsmokers and smokers who were given a prescription for nicotine replacement therapy,” the study concludes. The authors believe that “nicotine withdrawal left unaddressed may compromise psychiatric care…. Given the complicated relationship between mental illness and smoking, integration of cessation efforts into psychiatric care is recommended.”

During the first few hours after patients with schizophrenia enter smoke-free psychiatric emergency settings, more than half become agitated, and 6 percent are physically restrained, according to a recent study by Dr. Michael H. Allen and coworkers at the University of Colorado School of Medicine. Published in the American Journal of Psychiatry,[iii] the double-blind study looked at 40 patients admitted to the psychiatric emergency service of the Hospital of the University of Geneva, and found that a relatively safe and simple addition to the emergency stabilization of patients with schizophrenia—a 21 mg nicotine patch—markedly reduced agitation in patients who smoked. The practice of “forced abstinence,” which is the consequence of recent trends toward smoke-free institutions, may not be in the patient’s best interest—especially since formal smoking cessation programs are not always a part of hospital routine.

Allen and colleagues gave out either the nicotine patch or a placebo patch to 40 smokers recently admitted to the hospital with symptoms of schizophrenia. While agitation diminished over time in both the intervention group and the placebo group, “the intervention group had a 33 percent greater reduction in agitation at 4 hours and a 23 percent greater reduction at 24 hours.” The authors say that the differences are similar to those observed in industry trials of common antipsychotics. According to Allen, “forced tobacco abstinence may have the effect of increasing aggressive behavior.”

For patients with schizophrenia, smoking works

The importance of nicotine to patients with schizophrenia should not be underestimated. There are rational biological reasons why schizophrenics smoke.  A review of earlier studies published in Psychiatric Services suggests that smokers with schizophrenic symptoms may be self-medicating to improve the processing of auditory stimuli, and to reduce the side-effects caused by common antipsychotic medications.[iv]

“Neurobiological factors provide the strongest explanation for the link between smoking and schizophrenia,” writes Edward R. Lyon, the study’s author, “because a direct neurochemical interaction can be demonstrated.” Flaws in sensory gating, the process by which the brain lowers its response to a repeated sound, are believed to be involved in the auditory hallucinations common to people with schizophrenia. And sensory gating improves for schizophrenics after they load up on nicotine.  Other research has shown a reduction in expression of nicotinic receptors in schizophrenia, suggesting that a susceptibility to smoking and schizophrenia may be related.

Prochaska sees smoking among patients in psychiatric settings as the consequence of several factors, including clinicians’ failure to treat nicotine addiction, as well as the role nicotine plays as an antidote to drug side effects. Patients are familiar with the side effects of the drugs they take, “so they smoke and it reduces the blood levels of their medications,” she says. “They’re less sedated, and they can focus more.”

This complicates the picture for psychiatric staff: Antipsychotic drugs are metabolized faster in smokers, leading to the need for higher doses of medication. Prochaska notes that tobacco smoke may inhibit the effect of commonly used drugs like haloperidol, and the inhibition “can be as high as an increase clearance of 40–98 percent for olanzapine, a costly medication.”[v]

In an interview, Prochaska said that the heaviest smokers “may need to stay on cessation medications for an extended period, and that’s certainly better for them than smoking. Combination therapy also is recommended. In our studies, we combine the nicotine patch with gum or lozenge so they’re able to add to the patch to get sufficient coverage of withdrawal symptoms.”

Mental health professionals have traditionally argued that patients with schizophrenia do not want to quit smoking, but Prochaska’s work suggests otherwise. Patients in psychiatric settings are about as likely as the general population to want to quit smoking, her research shows. “There is growing evidence that smokers with mental illness are as ready to quit as other smokers and can do so without any threat to their mental health recovery,” she said.

By some estimates, people with psychiatric disorders make up almost half of the current U.S. market for tobacco products. As Prochaska has written, “nicotine dependence is the most prevalent substance use disorder among adult psychiatric patients, and it needs to be placed on the radar of psychiatric practice.”

It’s up to healthcare providers to get the ball rolling. “Many facilities are still struggling with it,” she says. “It’s not been in their purview traditionally, so changing the culture is a big piece of the solution. It’s very much a matter of trying to get tobacco treatment medicalized, having it be automatic, so that nicotine replacement is right there in the admitting orders. And ideally, working with patients while they are hospitalized to motivate smoking cessation, and supporting them when they leave.”


[i] Prochaska, JJ. Smoking and Mental Illness — Breaking the Link. New England Journal of Medicine. 2011, 365: 196-198.

[ii] Prochaska JJ, Gill P, and Hall SM. Treatment of Tobacco Use in an Inpatient Psychiatric Setting. Psychiatric Services. 2004, 55(11): 1265-1270.

[iii] Allen MH, Debanné M, Lazignac C, Adam E, Dickinson LM, Damsa C. Effect of nicotine replacement therapy on agitation in smokers with schizophrenia: a double-blind, randomized, placebo-controlled study. American Journal of Psychiatry. 2011, 168(4): 395-396.

[iv] Lyon ER. A Review of the Effects of Nicotine on Schizophrenia and Antipsychotic Medications. Psychiatric Services. 1999, 50(10): 1346-1350.

[v] Prochaska, JJ. Ten Critical Reasons for Treating Tobacco Dependence in Inpatient Psychiatry. Journal of the American Psychiatric Nurses Association. 2009, 15(6): 404–409.