Severe mental illness and substance use disorder frequently co-occur. Individuals suffering from schizophrenia?a common, persistent, and severe mental illness?have much higher rates of heavy alcohol use and smoking than the general population. Similarly, individuals with substance use disorder often suffer from other mental illnesses. For example, 22% of individuals with alcohol use disorder have another mental illness, compared to 11% of individuals without alcohol use disorder. Despite the prevalence of comorbidity, it is not known whether shared genetic factors contribute to schizophrenia and substance use disorders. In this study, we use existing genome-wide association study (GWAS) data and state-of-the-art statistical methodology to evaluate whether schizophrenia shares genetic factors with alcohol use disorder or nicotine dependence. Specifically, in aim 1 we will evaluate whether genetic factors that contribute to schizophrenia also contribute to alcohol use disorder and to nicotine dependence. Then, in aim 2, we will evaluate whether genetic factors that contribute to either alcohol use disorder or nicotine dependence also contribute to schizophrenia. This novel proposal is significant because it will lead to improved understanding of comorbidity of schizophrenia with alcohol use disorder and with nicotine dependence at a genetic level.

Public Health Relevance

Individuals with alcohol use disorder or nicotine dependence are much more likely to have mental illness than the general population. However, no study has evaluated whether there are shared genetic factors between substance use disorders and severe mental illness. In this study, we address this scientific gap by using existing data to evaluate whether schizophrenia shares genetic factors with alcohol use disorder or nicotine dependence. This study will lead to improved understanding of the genetic factors that may lead to the co- occurrence of schizophrenia with alcohol use disorder or nicotine dependence.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AA024888-02
Application #
9462002
Study Section
National Institute on Alcohol Abuse and Alcoholism Initial Review Group (AA)
Program Officer
Parsian, Abbas
Project Start
2017-04-01
Project End
2019-03-31
Budget Start
2018-04-01
Budget End
2019-03-31
Support Year
2
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Washington University
Department
Psychiatry
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
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Hartz, Sarah M; Horton, Amy C; Oehlert, Mary et al. (2017) Association Between Substance Use Disorder and Polygenic Liability to Schizophrenia. Biol Psychiatry 82:709-715