Therapy or Pleiotropy? Analyzing the Connection Between Schizophrenia and Smoking

This study aimed to ascertain the reason for the widely observed prevalence of tobacco smoking among patients with schizophrenia. The reason for this line of inquiry is because in addition to causing malignancy, cardiovascular, and respiratory sequelae in smokers, tobacco smoking in patients with schizophrenia has been shown to cause unique neurologic, cognitive, and memory deficits. Therefore, investigating the reasons for this tendency could enable physicians to provide patients with schizophrenia with the means to effectively quit. The studies cited in this literature review were obtained by searching through Google Scholar, PubMed, and PubMed Central databases for full-text studies in the recent past conducted on human subjects, though no PRISMA checklist was created because this is not a systematic review. This review article highlights potential explanations for the association between schizophrenia and tobacco smoking. These include that tobacco smoking improves various symptoms of schizophrenia and that this may occur through the stimulation of specific receptors. Also, common genetic factors are identified, explaining the common neurologic abnormalities seen in both patients who smoke and those who have schizophrenia. In addition, this review highlights multiple shared specific genes that provide potential explanations for the link between schizophrenia and smoking. The results of the study therefore suggest that future researchers may find it productive to further investigate these neurologic, genetic, and receptor-based commonalities in the hopes of eventually creating schizophrenia medications that stimulate nicotinic acetylcholine receptors, or conversely, to eventually design screening tests or gene therapies geared towards one of the aforementioned genetic commonalities. Designing case-control or cohort studies to prove the utility of these drugs or tests may prove rewarding.