University of Southern California scientists have identified genes connected to mental health in one of the largest genomic studies in the history of mankind. 190 scientists from around the globe teamed up to analyze the genomes of 298,420 participants. Their findings include genetic variants that may be accountable for influencing our overall sense of well-being, symptoms of depression and even neuroticism.
The new study of behavioral genetics was published on April 18th, 2016 in the Nature Genetics journal. Daniel Benjamin, corresponding author and associate professor of the Center for Economic and Social Research in the USC Dornsife College of Letters, Arts and Sciences says while we have recognized for quite some time there was a correlation between genes and how we perceive the world around us, this is the first time more than a handful of genetic variants have been connected to these traits.
It is important to note that these genetic variants are not the determining factor to whether or not someone develops a poor sense of well-being, depression or neuroticism. Benjamin reminds us that psychological well-being is both affected by our genes and the environment we live in. He says the variants that have been discovered account for a small fraction of genetic associations.
Scientists discovered a total of three genetic variants associated with what they call “subjective well-being” over the course of their study. This measurement of well-being helps calculate how satisfied a person states they feel about their life. Tests were based on the analysis of about 300,000 people. Two variants were discovered that associate with symptoms of depression during an analysis of 180,000. 170,000 people were analyzed in the discovery of 11 genetic variants associated with neuroticism.
Daniel Benjamin says most of the genetic variants that were associated with depression and/or neuroticism were also directly linked to subjective well-being as well as the other way around. Examining each variant on its own doesn’t explain very much about the tested traits. However when they are studied as a whole, their findings would imply that the cumulative effects of anywhere from thousands to millions of variants influence traits such as depression, neuroticism and feelings of well-being. The study also found that the traits listed above are predominantly influenced by the same set of genes.
Medical researchers and psychologists within the interdisciplinary team also studied whether or not genetic variants that they discovered overlapped with the variants currently known to be directly associated with other diseases, such as Alzheimer‘s, anxiety, bipolar disorder and schizophrenia. Thus far, the strongest link appeared for anxiety disorders, while bipolar disorder and schizophrenia also show a decent amount of overlap.
Benjamin wants to make clear that it is still too soon to draw complete conclusions and strength of correlation between genes and biological mechanisms. He wants to remind us that genetics are only a single factor that works to influence psychological traits. Environmental factors are just as important and also work to interact with genetic effects on the mind and body.