Smoke, GPx activity and symptoms improvement in patients with drug-naive first-episode schizophrenia: A large-scale 12-week follow-up study

Smoking affects symptom improvement in schizophrenia: a prospective longitudinal study of male patients with first-episode schizophrenia

Patients with schizophrenia (SCZ) smoke up to three times more than general people. However, there are conflicting results regarding the relationship between tobacco smoke and clinical symptom severity in SCZ. The aim of this study was to assess the impact of smoking on clinical symptoms after antipsychotic treatment in a 12-week cohort study after controlling for confounding factors. One hundred and forty-five male patients with drug-naïve first-episode (DNFE) SCZ received antipsychotic monotherapy for 12 weeks. Symptom severity was assessed at baseline and at week 12 by the Positive and Negative Syndrome Scale (PANSS). We found no differences in clinical symptoms among male smokers with SCZ compared with male nonsmokers. However, male smokers showed greater improvement in negative symptoms after 12 weeks of treatment, controlling for age, years of education, onset age, and baseline body mass index (BMI). Our study showed that after 12 weeks of treatment with antipsychotics, male smokers showed greater improvement in negative symptoms than male nonsmokers.

Smoking Affects the Predictive Roles of Antioxidant Enzymes in the Clinical Response to Risperidone in Schizophrenia: A Large-scale Cohort Study

OBJECTIVES

There is overwhelming evidence of the relationship between smoking and schizophrenia (SZ). Tobacco smoke is considered to ameliorate the symptoms and reduce the side effects of antipsychotics in SZ patients. However, the underlying biological mechanism by which tobacco smoke improves symptoms in SZ remains unclear. This study was designed to examine the effects of tobacco smoke on antioxidant enzyme activities and psychiatric symptoms after receiving 12-week risperidone monotherapy.

METHODS

Two hundred and fifteen antipsychotic-naïve first-episode (ANFE) patients were recruited and treated with risperidone for 3 months. The severity of the patient's symptoms was assessed by the Positive and Negative Syndrome Scale (PANSS) at baseline and at post-treatment. Plasma SOD, GSH-Px, and CAT activities were determined at baseline and follow-up.

RESULTS

Relative to nonsmoking patients with ANFE SZ, patients who smoked had higher baseline CAT activity. In addition, among non-smokers with SZ, baseline GSH-Px was associated with clinical symptom improvement, while baseline CAT was associated with positive symptom improvement in smokers with SZ.

CONCLUSION

Our findings demonstrate that smoking affects the predictive role of baseline SOD, GSHPx, and CAT activities on clinical symptom improvement in patients with SZ.