Long term effects of smoking cessation in hospitalized schizophrenia patients

Abstract

BackgroundThe prevalence of smoking in patients with schizophrenia is higher than that in the general population and is an important medical issue. Short-term smoking cessation tends to worsen psychiatric symptoms in patients with schizophrenia but decreases sympathetic nervous system activity and improves plasma cholesterol levels in healthy people. Few studies have assessed the long-term effects of smoking cessation in patients with schizophrenia.MethodsSubjects were 70 Japanese patients with schizophrenia (38 smokers, 32 non-smokers). We compared the following clinical parameters between the two groups at baseline (before smoking cessation) and in each group separately between baseline and at three years after smoking cessation: autonomic nervous system activity, plasma cholesterol levels, body weight, drug therapy, and Global Assessment of Functioning scores. We also compared the mean changes in clinical parameters throughout this study between the groups at both time points. Autonomic nervous system activity was assessed by power spectral analysis of heart rate variability.ResultsParasympathetic nervous system activity and the doses of antiparkinsonian drugs in smokers were significantly higher than those in non-smokers at baseline. Smoking cessation was associated with significantly decreased sympathetic nervous system activity and decreased doses of antipsychotics and antiparkinsonian drugs at three years after smoking cessation. However, there was no significant difference in the mean change in clinical factors scores, except for Global Assessment of Functioning scores, between smokers and non-smokers at three years after smoking cessation.ConclusionsOur results suggest that smoking reduces both autonomic nervous system activity and the effectiveness of drug therapy with antipsychotics and antiparkinsonian drugs in patients with schizophrenia, but that both factors could be ameliorated over the long term by smoking cessation. Taken together with the findings of previous studies, smoking cessation in patients with schizophrenia has many long-term positive physiological effects.

Smoking Rates and Number of Cigarettes Smoked per Day in Schizophrenia: A Large Cohort Meta-Analysis in a Japanese Population

“…We found 89 relevant articles in PubMed and Web of Science using the search terms mentioned in the Methods section. Of these, a total of 12 studies, including the present study, met the inclusion criteria (supplementary Figure 2) for our meta-analysis (1.845 Japanese SZ patients) (Shimoda et al, 1999; Mori et al, 2003; Yoshimura et al, 2008; Moriwaki et al, 2009; Kobayashi et al, 2010; Shinozaki et al, 2011; Watanabe et al, 2012; Sasayama et al, 2013; Niitsu et al, 2014; Oniki et al, 2016; Miyauchi et al, 2017). Although the definitions of the smoking status differed slightly among the studies (supplementary Table 1), we were able to obtain current smoking rates for Japanese SZ patients.…”

Lung cancer incidence in patients with schizophrenia: meta-analysis

“…Previous studies showed a higher prevalence of tobacco smoking and higher risk of lung cancer in patients with schizophrenia than in the general population. [2][3][4] However, results of a previous meta-analysis did not support this notion, showing that the risk of lung cancer incidence was higher than the general population. 5 Indeed, a previous genetic study reported that differences in p53 polymorphisms might be responsible for the genetic association between patients with schizophrenia and a potentially reduced risk of lung cancer, 6 which further complicates the association between schizophrenia and lung cancer risk.…”

Mendelian Randomization and GWAS Meta Analysis Revealed the Risk-Increasing Effect of Schizophrenia on Cancers

“…The relationship between psychiatric disorders and tumors has sparked much interest and controversy [ 1 ]. On the one hand, the health of patients with Schizophrenia (SCZ) is affected by a multitude of risk factors associated with cancer development, such as smoking [ 2 , 3 ], alcohol [ 4 ], drug abuse [ 5 ], obesity [ 6 ], and physical inactivity [ 7 ]. Some epidemiological and meta-analyses have argued that SCZ can increase the risk of breast cancer [ 8 , 9 ].…”