Other investigators have knocked down genes involved with neurogenesis or blocked neurogenesis directly in rodents, which eliminated the animals' ability to respond to anti-depressants. This supports the hypothesis that neurogenesis is involved in the response to antidepressant treatment in humans.
McMahon and colleagues studied over 1900 study participants with major depression who donated a blood sample and received the antidepressant citalopram over a period of at least 6 weeks.
In addition to providing valuable information that may be ultimately useful in a clinical treatment setting, the study is part of a larger movement in depression research.
"This is the beginning of a new generation of studies to help clinicians personalize treatment." noted Dr. Thomas Insel, Director of the National Institute of Mental Health (NIMH). "I predict that genomics will be an important tool for future psychiatrists treating people with depression just as it is being used today by oncologists selecting treatments for breast cancer or lymphoma."
McMahon noted that this success is just the beginning. "Ultimately, our goal is to put together a panel of genetic markers that can guide treatment decisions and help doctors choose an antidepressant that will work best for an individual patient."