ABSTRACT
Smoking prevalence in schizophrenia is considerably larger than in general population, playing an important role in early mortality. We compared the polygenic contribution to smoking in schizophrenic patients and controls to assess if genetic factors may explain the different prevalence. Polygenic risk scores (PRSs) for smoking initiation and four genetically correlated traits were calculated in 1108 schizophrenic patients (64.4% smokers) and 1584 controls (31.1% smokers). PRSs for smoking initiation, educational attainment, body mass index and age at first birth were associated with smoking in patients and controls, explaining a similar percentage of variance in both groups. Attention-deficit hyperactivity disorder (ADHD) PRS was associated with smoking only in schizophrenia. This association remained significant after adjustment by psychiatric cross-disorder PRS. A PRS combining all the traits was more explanative than smoking initiation PRS alone, indicating that genetic susceptibility to the other traits plays an additional role in smoking behaviour. Smoking initiation PRS was also associated with schizophrenia in the whole sample, but the significance was lost after adjustment for smoking status. This same pattern was observed in the analysis of specific SNPs at the CHRNA5-CHRNA3-CHRNB4 cluster associated with both traits. Overall, the results indicate that the same genetic factors are involved in smoking susceptibility in schizophrenia and in general population and are compatible with smoking acting, directly or indirectly, as a risk factor for schizophrenia that contributes to the high prevalence of smoking in these patients. The contrasting results for ADHD PRS may be related to higher ADHD symptomatology in schizophrenic patients.
Subject(s)
Schizophrenia/genetics , Tobacco Smoking/genetics , Adult , Attention Deficit Disorder with Hyperactivity/genetics , Body Mass Index , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Middle Aged , Multifactorial Inheritance , Nerve Tissue Proteins/genetics , Phenotype , Receptors, Nicotinic/genetics , Risk Factors , Sociodemographic FactorsABSTRACT
The objective of this study was to identify factors associated with hospital admission after suicide spectrum behaviors. Patients' characteristics, the nature of the suicidal behavior, admission rates between centers, and factors associated with admission have been examined in suicide spectrum presentations to emergency departments in 3 Spanish cities. The intent of the suicidal behavior had the greatest impact on hospitalization. Older age, living alone, self-harm method not involving drug overdose, previous history of suicide spectrum behaviors, and psychiatric diagnosis of schizophrenia, mood, or personality disorder were independently associated with being admitted. There was a 3-fold between-center difference in the rate of hospitalization. Widespread differences in the rate of hospitalization were primarily accounted for by characteristics of the individual patients and their suicidal behavior.