Why do patients with schizophrenia smoke?
OBJECTIVE
Among the mentally ill, smoking prevalence is highest in patients with schizophrenia ( approximately 70-80%). This can impose a significant financial burden on patients, not to speak of increased smoking-related morbidity and mortality. Therefore, it is critical for clinicians to understand why patients with schizophrenia smoke in order to adapt treatment schemes. Understanding the reasons may also help to develop new drugs that target the nicotinic system in the brain as well as smoking cessation programs that are specifically designed for this particular patient population.


RESULTS
So far, several reasons have been identified which are believed to explain tobacco consumption in patients with schizophrenia. Originally, it was widely believed that patients with schizophrenia smoke to increase hepatic clearance and to restore the dopamine blockade of certain antipsychotic drugs to diminish their side effects. However, more recently it became obvious that cigarette smoking may also be reinforcing for patients because it improves psychiatric symptoms, most notably negative and cognitive symptoms. The underlying molecular mechanisms of these nicotine effects are currently under intensive investigation.


CONCLUSIONS
Heavy smoking in schizophrenia cannot simply be viewed as a 'bad habit'. Rather, self-medication of clinical symptoms and side effects of antipsychotic drugs appear to play a major role.
Winterer
Georg
G
Department of Psychiatry, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany. georg.winterer@uni-duesseldorf.de
D000223:Adaptation, Psychological; D003072:Cognition Disorders / Q000453:epidemiology / Q000517:prevention & control; D005731:Ganglionic Stimulants / Q000494:pharmacology*; D006801:Humans; D051596:Neurocalcin / Q000187:drug effects / Q000235:genetics; D009538:Nicotine / Q000494:pharmacology*; D015995:Prevalence; D011582:Psychological Theory; D011950:Receptors, Cholinergic / Q000187:drug effects; D012054:Reinforcement, Psychology; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics; D012651:Self Medication; D015398:Signal Transduction / Q000187:drug effects; D012907:Smoking / Q000453:epidemiology*
D005731:Ganglionic Stimulants; D051596:Neurocalcin; D011950:Receptors, Cholinergic; C496688:VSNL1 protein, human; D009538:Nicotine