ABSTRACT
BACKGROUND: A functional polymorphism in the catechol-O-methyltransferase (COMT) gene (Val158Met) appears to influence cognition in people with alcohol/substance use disorders (AUD/SUD) and in those with psychosis. METHODS: To explore the potential moderating effect of these factors, a cross-sectional study was conducted, randomly recruiting subjects with DSM-IV diagnosis of schizophrenia. AUD/SUD was rigorously assessed, as well as COMT Val158Met polymorphism. Executive control functioning was measured using the Intra-Extra Dimensional Set Shift (IED). The effect of a possible interaction between comorbid AUD/SUD and COMT Val158Met polymorphism on IED scores was explored. RESULTS: Subjects with schizophrenia, comorbid AUD/SUD, and MetMet carriers for SNP rs4680 of the COMT gene showed worse performance on IED completed stages scores, as compared with individuals with ValVal genotype. However, among subjects without AUD/SUD, those with the MetMet variant performed better than people carrying ValVal genotype. CONCLUSIONS: This study is the first to date examining the impact of COMT on cognition in a highly representative sample of people with schizophrenia and comorbid AUD/SUD. Differential moderating effects of COMT Val/Met genotype variations may similarly influence executive functions in people with schizophrenia and comorbid AUD/SUD.
Subject(s)
Catechol O-Methyltransferase/genetics , Executive Function/physiology , Methionine/genetics , Schizophrenia/genetics , Substance-Related Disorders/genetics , Valine/genetics , Adult , Cognition/physiology , Comorbidity , Cross-Sectional Studies , Diagnosis, Dual (Psychiatry)/methods , Female , Humans , Male , Middle Aged , Polymorphism, Genetic/genetics , Random Allocation , Schizophrenia/diagnosis , Schizophrenic Psychology , Substance-Related Disorders/diagnosis , Substance-Related Disorders/psychologyABSTRACT
OBJECTIVE: To examine the association between posttraumatic stress disorder (PTSD) and obesity in the literature to date. DATA SOURCES: We systematically searched PubMed, Embase, Scopus, Web of Science, and ProQuest from database inception till September 2013. Search phrases combining the terms Obesity and Post-Traumatic Stress Disorder were used. STUDY SELECTION: We selected observational studies estimating obesity prevalence in samples of people with PTSD, as well as in comparison groups without PTSD. DATA EXTRACTION: Obesity rates as well as demographic, clinical, and methodological variables were extracted from each publication or obtained directly from its authors. RESULTS: A total of 113, 395, 59, 115, and 400 records were generated from PubMed, Embase, Scopus, Web of Science, and ProQuest, respectively. Thirteen studies were eligible according to inclusion criteria. The pooled crude odds ratio (OR) and 95% confidence interval (CI) for obesity among people with PTSD, based on 589,781 subjects, was 1.55 (1.32-1.82). A large heterogeneity was found (I(2) = 90%), and risk of publication bias was statistically significant (P = .002). However,subgroup and sensitivity analyses including only studies with most accurate methods to assess obesity (OR = 1.35; 95% CI,1.05-1.74; I(2) = 47%) and PTSD (OR = 1.82; 95% CI, 1.33-2.50; I(2) = 75%) also confirmed the association between PTSD and obesity. CONCLUSIONS: Despite some limitations, individuals suffering from PTSD seem more likely, relative to controls, to suffer from obesity. As such, individuals with this comorbidity should be targeted for intensive prevention and treatment focused on both disorders. Future research is needed to identify the role of unknown factors and mediators that might clarify the nature of this association.