Nearly 80 genes have been linked to depression in a new report that could help explain why some people may be at a higher risk for the condition.
Researchers have long struggled to pinpoint the causes of depression, which is the leading cause of disability among adults under 44 affecting an estimated 16 million Americans and 13 million people in the UK.
The UK study published Monday is part of a growing body of evidence suggesting that genetic factors play a significant role in the development of the condition that has become increasingly common in the last decade.
The authors emphasized that these findings could lead to a better understanding the underlying causes of depression and the creation of more effective treatment.
A new study of 300,000 people in the UK has identified 80 genes linked to depression, supporting previous research that the condition is partly influenced by genetic factors
‘This study identifies genes that potentially increase our risk of depression, adding to the evidence that it is partly a genetic disorder,’ said lead author Dr David Howard, a professor at the University of Edinburgh’s Centre for Clinical Brain Sciences.
‘The findings also provide new clues to the causes of depression and we hope it will narrow down the search for therapies that could help people living with the condition.’
While life events such as trauma or stress have been found to contribute to the onset of depression, it is unclear why some people appear to be more likely to develop the condition.
Twin studies have shown that approximately 40 percent of people with depression were genetically predisposed to the condition.
The study published Monday was part of a £4.7 million ($7 million) project to better understand the condition called Stratifying Resilience and Depression Longitudinally.
The researchers from the University of Edinburgh analyzed data from more than 300,000 people in the UK to search for genetic indicators of depression.
Several of the nearly 80 genes identified have been known to be involved in the function of synapses, tiny connectors that facilitate communication in the brain through electrical and chemical signals.
Why are depression rates higher in women than in men?
Women are twice as likely to suffer from depression than men, according to the most recent figures from the Centers for Disease Control and Prevention.
Eight percent of American adults over 20 are depressed, including 5.5 percent of men and 10.4 percent of women.
Previous research has attempted to explain the disparity citing hormonal fluctuations or the possibility that women may simply be more likely to admit to suffering from the condition.
However, experts have warned that depression should not be considered a ‘normal’ part of womanhood and that more research is needed to determine the causes of the gender differences.
This fits with previous research that has shown an association between depression and serotonin, a ‘feel good’ chemical also involved in the brain’s communication processes.
Imbalances in serotonin have been implicated in the development of mood disorders and other issues such as obsessive-compulsive disorder and panic attacks.
The findings published in the journal Nature Communications were confirmed through a cross-reference with data from California-based genetics-research firm 23andMe.
‘These new findings help us better understand the causes of depression and show how the study and big data research has helped advance mental health research,’ said co-author Andrew McIntosh, a professor at the University of Edinburgh’s Centre for Clinical Brain Sciences.
‘We hope that the UK’s growing health data research capacity will help us to make major advances in our understanding of depression in coming years.’
Eight percent of people in the US have experienced depression, which has been found to raise the risk of other serious health concerns including obesity and suicide.
People with depression are four times as likely to have a heart attack a heart attack than those without a history of the illness, and after a heart attack, they are at a significantly increased risk of death or second heart attack.
The condition has also been linked to significantly heightened risk of drug abuse, drug overdose and suicide.
Depression is considered to be one of the easier mental illnesses to treat, but only one third of people suffering with depression will seek treatment, according to the Depression and Bipolar Support Alliance.