Page 23 - JCBP-1-1

Journal of Clinical and
Basic Psychosomatics Smoking and schizophrenia symptoms

Table 1. (Continued)
Study Goal of study Main relevant results
Increased levels of the nicotine metabolite cotinine in Determine if SCZ patients self-administer SCZ patients’ higher dose of
schizophrenic smokers compared to other smokers [71] more nicotine during smoking than nicotine may target different
non-SCZ. receptors than those activated by
the lower doses self-administered
by most non-SCZ smokers.
Strain-specificity in nicotine attenuation of Individuals with SCZ may display Treatments targeting genetic
phencyclidine-induced disruption of prepulse inhibition elevated rates of tobacco smoking as a dysfunctions in nicotinic-
in mice: Relevance to smoking in SCZ patients [27] means of self-medicating against deficits glutamatergic interactions would
in sensory gating. treat cognitive problems.
Abbreviations: SCZ: Schizophrenia; AP: Antipsychotic, NMDA: N-methyl-D-aspartate.

[39]
nicotinic agonist that targets alpha-7 nicotinic receptors, likely to smoke compared to the general population .
[33]
has shown promise in improving negative symptoms . Overall, gender is a major confounding factor that can
Future studies are needed to explore and understand the contribute to inconsistent findings regarding smoking
relationship between smoking and negative symptoms in prevalence.
more details.
4.2. Age
3.1.4. Comparison of movement disorder Limited research exists on the relationship between age
TD is a common movement disorder that can occur in and smoking behavior, but certain studies have observed
patients taking both first- and second-generation AP . that the non-smoking group tended to be older compared
[34]
One study suggests that nicotinic cholinergic may reduce to the smoking group . Among men, the highest smoking
[40]
dyskinesias . Similarly, another study reported a stronger rate was observed in the older age category, while the
[35]
motivation to smoke in SCZ patients compared to control lowest rate was observed in the younger age category .
[41]
subjects for reasons related to pleasure from smoking and However, a study conducted in 2012 found that smokers
the need for psychomotor stimulation . tended to be younger . Therefore, it is important to
[18]
[36]
consider participants’ age when examining the association
4. Discussion between smoking status and SCZ symptoms.
The present review shows that smoking is associated with 4.2.1. Positive symptoms
the severity of positive, extrapyramidal, negative, and
cognitive symptoms in SCZ. In addition, most studies found The existing literature yields inconsistent findings in this
a significant association between cognitive symptoms and field. However, most studies have suggested a link between
smoking, indicating the role of dopamine. In addition increased positive symptoms and smoking [28,29] . Smoking
to social and environmental factors, smoking might has been linked with positive symptoms in acute psychiatric
contribute to the hyperactivation of the inflammatory disorders , which might also influence the development
[31]
system observed in SCZ, partially accounting for the of psychosis . Further studies employing a longitudinal
[30]
symptom severity. In addition to the duration of smoking, design are needed to investigate the relationship between
several factors should be considered systematically in positive symptoms and smoking.
future studies. Gender, age, duration of illness, detailed
medication, and psychosocial information might play 4.2.2. Negative symptoms
essential roles and interact with smoking status. As we found, the literature in this field was limited, reflecting
a complex and multifaceted relationship. While smoking
4.1. Gender may temporarily relieve specific symptoms, it can also

Biological, genetic, and social theories have been proposed contribute to developing or worsening negative symptoms
to explain the gender differences observed in smoking over time. Thus, clinicians must address smoking cessation
prevalence. Multiple studies have identified a higher as part of a comprehensive treatment plan for SCZ.
frequency of smoking among males [18,37] . Particularly, the
study by Hou et al. confirmed the hypothesis of a higher 4.2.3. Cognitive symptoms
smoking rate in males and reported rates of 53.6% and 4.0% Smoking has been proposed to alleviate cognitive deficits
for men and women, respectively . However, Xu et al. in SCZ by increasing dopaminergic neurotransmission
[38]
found that male Chinese patients with SCZ were not more in the prefrontal areas . The literature on cognitive SCZ
[42]
Volume 1 Issue 1 (2023) 6 https://doi.org/10.36922/jcbp.1014