What is the research about?

Most psychiatric disorders are known to have a genetic component, usually related to small changes in the DNA called single nucleotide polymorphisms (SNPs, pronounced “snips”), the most common type of genetic variation . What is not well understood is whether these differences are unique to each disorder or if multiple disorder share them. The goal of this study was to examine if there is shared genetic etiology among five disorders: Schizophrenia, Bipolar Disorder, Major Depressive Disorder, Autism Spectrum Disorder (ASD), and Attention Deficit/Hyperactivity Disorder (ADHD).


What did the researchers do?

The researchers looked at the genetic relationships amongst 5 disorders that could be explained by SNPs. To do this, the author analyzed very large samples of individuals with one of the 5 disorders (“cases”) and individuals with none of the disorders (“controls”). The researchers then compared the genetics of the cases to the controls, the genetics of cases to other cases with the same disorder, and then to cases with a different one of the 5 disorders.


What did the researchers find?

This study found the following degrees of genetic relationship between disorders:

High: Schizophrenia and Bipolar Disorder

Moderate: Schizophrenia and Major Depressive Disorder

ADHD and Major Depressive Disorder

Low: Schizophrenia and ASD


Take home message

This studied showed that, to varying degrees, individuals with schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder and attention deficit/hyperactivity disorder share certain similar genetic variations. This could provide new insights into potential causes for the development of these disorders and suggests that research be done to investigate changes in the way the body works that are common in these disorders.


Notes

The original Research Report was written by the Cross-Disorder Group of the Psychiatric Genomics Consortium and was published in Nature Genetics in 2013.