Neurobiological Determinants of Tobacco Smoking in Schizophrenia

Abstract

Purpose of review: To provide an overview of the underlying neurobiology of tobacco smoking in schizophrenia, and implications for treatment of this comorbidity.Recent findings: Explanations for heavy tobacco smoking in schizophrenia include pro-cognitive effects of nicotine, and remediation of the underlying pathophysiology of schizophrenia. Nicotine may ameliorate neurochemical deficits through nicotine acetylcholine receptors (nAChRs) located on the dopamine, glutamate, and GABA neurons. Neurophysiological indices including electroencephalography, electromyography, and smooth pursuit eye movement (SPEM) paradigms may be biomarkers for underlying neuronal imbalances that contribute to the specific risk of tobacco smoking initiation, maintenance, and difficulty quitting within schizophrenia. Moreover, several social factors including socioeconomic factors and permissive smoking culture in mental health facilities, may contribute to the smoking behaviors (initiation, maintenance, and inability to quit smoking) within this disorder.Summary: Tobacco smoking may alleviate specific symptoms associated with schizophrenia. Understanding the neurobiological underpinnings and psychosocial determinants of this comorbidity may better explain these potential beneficial effects, while also providing important insights into effective treatments for smoking cessation.

mGluR5 receptor availability is associated with lower levels of negative symptoms and better cognition in male patients with chronic schizophrenia

“…Acknowledging the very high prevalence of smoking (more than 60%) in subjects with schizophrenia (Chapman, Ragg, & McGeechan, ) and their greater difficulties in quitting smoking (Wing, Wass, Soh, & George, ), a more precise understanding of the common neurobiological basis of schizophrenia and nicotine dependence is of particular importance. Several investigations have emphasized the potential usage of tobacco by schizophrenia patients for self‐medication purposes in order to alleviate specific symptoms (Lucatch, Lowe, Clark, Kozak, & George, ), particularly negative symptoms and dysfunctional reward circuits (Peechatka, Whitton, Farmer, Pizzagalli, & Janes, ). However, investigations in this field have yielded mixed findings.…”

Use of tobacco in schizophrenia: A double‐edged sword

“…An established hypothesis proposed that neurotransmitter dysfunction (e.g., dopamine, glutamate, gamma‐aminobutyric acid, and acetylcholine) is the important pathological mechanism of schizophrenia (Devor et al, ; Dineley, Pandya, & Yakel, ; McCutcheon, Abi‐Dargham, & Howes, ; Wierońska & Pilc, ). Nicotine—the addictive ingredient in tobacco—binds to the nicotinic acetylcholine receptors, which are expressed in the human brain and influence neurotransmitter systems, thereby normalizing neurotransmitter dysfunction and improving disease (Lucatch et al, ).…”

“…Ach, acetyl choline; DA, dopamine; GABA, gamma-aminobutyric acid; GLU, glutamic acid; nAChRs, nicotine acetylcholine receptors rather than a cause of schizophrenia. The self-medication hypothesis may provide an interpretation, which states that patients with schizophrenia smoke to alleviate clinical symptoms, cognitive deficits, and the side effects of antipsychotic medications (Lucatch et al, 2018). The potential neurobiological mechanism involved in this process is shown in Figure 3.…”

“…Schizophrenic patients (SPs) exhibit a higher rate of smoking than the general population, even after adjusting for an array of potential confounding factors (Zhang et al, ). The use of tobacco is an established cause of physical health problems (e.g., cardiovascular disorders, chronic respiratory disorders, lung cancer, and other malignancies), which may result in early death among individuals with schizophrenia (GBD, 2015 Tobacco Collaborators, ; Lucatch, Lowe, Clark, Kozak, & George, ). The etiology of predisposition to smoking in schizophrenia remains largely unknown.…”

“…The use of tobacco is an established cause of physical health problems (e.g., cardiovascular disorders, chronic respiratory disorders, lung cancer, and other malignancies), which may result in early death among individuals with schizophrenia (GBD, 2015Tobacco Collaborators, 2017Lucatch, Lowe, Clark, Kozak, & George, 2018).…”