title: Nicotine dependence, symptoms and oxidative stress in male patients with schizophrenia.
abstract: The high rate of smoking in schizophrenia may reflect patients' attempts to reduce the side effects of antipsychotic medications, and one mechanism for this reduction may be a reduction in oxidative stress and free radical-mediated brain damage that may contribute to schizophrenic symptoms and to complications of its treatment. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS), side effects were assessed with the Simpson and Angus Rating Scale (SAS), and malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured in plasma. All of these measures were compared in 130 male inpatients with DSM-IV schizophrenia: 104 smokers and 26 non-smokers. The results showed that the positive PANSS symptoms were lower in smokers than non-smokers (14.5 vs 17.5), while the negative symptoms were lower in those who smoked more cigarettes (r=-0.23). The SAS showed no differences. The CAT activity was correlated with both GSH-Px and SOD activities. Of the three enzymes only the CAT activity was significantly higher in smokers than non-smokers (2.9 vs 1.6 U/ml), but greater SOD activity correlated more cigarettes smoked (r=0.24). Consistent with some protection against oxidative stress, MDA also was significantly lower in smokers than non-smokers (9.2 vs 14.4 nmol/ml). The fewer positive symptoms in smokers and fewer negative symptoms in those who smoked more cigarettes may be a selection bias, but appears to be associated with decreased oxidative stress and lipid peroxidation in schizophrenics who smoke tobacco.
authors.affiliation: Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, 2002 Holcombe Boulevard, Houston, TX 77030, USA. xyzhang@bcm.edu
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Zhang
authors.forename: Yun Long
authors.initials: YL
authors.lastname: Tan
authors.forename: Dong Feng
authors.initials: DF
authors.lastname: Zhou
authors.forename: Colin N
authors.initials: CN
authors.lastname: Haile
authors.forename: Gui Ying
authors.initials: GY
authors.lastname: Wu
authors.forename: Lian Yuan
authors.initials: LY
authors.lastname: Cao
authors.forename: Therese A
authors.initials: TA
authors.lastname: Kosten
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kosten
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001526:Behavioral Symptoms; D002374:Catalase / Q000378:metabolism; D016009:Chi-Square Distribution; D005979:Glutathione Peroxidase; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000097:blood / Q000150:complications*; D012565:Schizophrenic Psychology; D013482:Superoxide Dismutase / Q000378:metabolism; D014029:Tobacco Use Disorder / Q000097:blood / Q000150:complications*
chemical_list: D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase