As the prevalence of tobacco use has decreased, it has become clear that individuals with
mental illness comprise a substantial portion of the remaining smokers. Seventy to eighty percent of patients with
schizophrenia smoke and their smoking is established before their first psychotic episodes or the initiation of treatment. Many patients with
schizophrenia, and approximately 50% of their first degree relatives have abnormalities in auditory sensory gating and/or smooth pursuit eye movements. These abnormalities are corrected by
nicotine, and they appear to be transmitted as autosomal dominant traits. Evidence is accumulating that these abnormalities reflect genetic variations in
nicotine receptor number and function, that may increase susceptibility for
schizophrenia. Recent studies suggest that
bupropion, added to treatment with an atypical
antipsychotic, can enhance the likelihood of smoking cessation or reduction in patients with
schizophrenia. The prevalence of smoking is also substantially increased among patients with
bipolar disorder, perhaps especially so among those with psychotic features.
Nicotine delivered by gum or
transdermal patch can provide short term relief for exacerbations of
Tourette's Syndrome, but its use is limited by frequent toxicity, primarily
nausea.