Neural Inhibition as a Mechanism of Nicotine Dependence Among Persons With Schizophrenia
Status:
Completed
Trial end date:
1969-12-31
Target enrollment:
Participant gender:
Summary
Cigarette smoking decreases life expectancy, causes devastating health complications, and
costs society billions of dollars each year. These untoward consequences are especially
pronounced among persons with schizophrenia (SCZ) because approximately 80% to 95% of this
group smokes cigarettes. These high prevalence rates underscore the need for research
investigating the determinants of smoking in patients with SCZ. Several researchers have
observed that nicotine improves specific symptoms of SCZ including negative symptoms,
negative affect, and cognitive deficits. This has led to the hypothesis that patients with
SCZ smoke in an attempt to self-medicate. However, the mechanism(s) by which nicotine has its
positive effect on symptoms remains unclear. The current proposal posits that neural
inhibition (NI) is a physiological mechanism of this effect, while variation in the
alpha-7-nicotinic receptor subunit gene (CHRNA7) represents the genetic underpinnings of
these processes. The proposed study will assess NI and symptom improvement after acute
administration of nicotine to both smokers and nonsmokers with SCZ. In addition, NI and
CHRNA7 variation will be tested as predictors of patients' ability to reduce/quit smoking
following smoking treatment. These data may lead to the development of new pharmacological
strategies for treating the symptoms of SCZ and new methods for assisting these patients to
quit smoking.