VCU launches huge new study of genetics and depression
Kenneth Kendler is a Professor of Psychiatry and Human Genetics at VCU. He’s spent many years thinking about why people get depressed, how their condition can be diagnosed and treated.
"Depression is one of the most important of psychiatric disorders. It’s probably the commonest of the disorders," he says. "Roughly 10-15% of people will have a major depressive episode in their life."
It’s twice as common in women as in men, and – along with back pain -- it’s considered a leading cause of disability.
Thanks to earlier studies, we know there’s a genetic component to the disease.
"Mostly in the 1980’s and 1990’s a series of well-done twin studies were done that gave us a pretty accurate take on the overall important of genetic factors.," Kendler recalls. "The answer to that is about 40% of the individual differences between people and their vulnerability is through the genes they get from their mother and father."
But those studies involved people of European descent. Far less was known about the causes of depression in other parts of the world, so the National Institute of Mental Health put out a call for studies on that subject.
Kendler had done research in China. Now, joining forces with a colleague at UCLA and at the Seoul National University Hospital in Korea, he proposed an in-depth study of women in that country, and the institute offered nearly $9 million to make it happen.
"We want to interview a total of 20,000 individuals, about ten thousand with severe major depression and a matched group of controls that are just like the cases except they don’t have depression," he says.
Each person will be interviewed for 90 minutes –asked about mood, sleep and appetite, which vary greatly in people of European descent. Eighty percent of people when they get depressed sleep less, lose weight and 20% gain weight and sleep more.
Korean study subjects will be asked about incidence of anxiety or panic and past traumatic events that make depression more likely. The hope is to better define the disease – to understand what it looks like in different people and different cultures.
"The idea that depression is a single disease – it’s kind of like obesity, right or hypertension – these very complex disorders with many, many genetic variants, and so the way forward in our view is you have to collect a large sample and then look at sub-types."
From this new understanding, Kendler hopes science might develop tests – ways to identify people at risk for depression – and medications.
“I would die happy if we could contribute to that long-term goal," Kendler says.
In five years he hopes to complete the study and compile the largest collection of data about depression in East Asia. Those numbers would then be compared with databases in the U.S. and Europe.