A group of research centers spanning five continents is in the middle of a clinical trial intended to identify genetic and other markers that can predict response to three antidepressants.
According to Subhdeep Virk, a psychiatrist and principal investigator of the study at Ohio State’s Wexner Medical Center, the International Study to Predict Optimized Treatment of Depression, or iSPOT-D, is the largest biomarker discovery effort to identify predictors for depression treatment response.
Because depression is a genetically heterogeneous disorder, smaller studies looking at single markers have not shown much success, Virk told PGx Reporter this week. The iSPOT-D group hopes its more comprehensive approach will identify combinations of genetic and other predictive markers that physicians can use as an objective tool to choose antidepressants more likely to work for individual patients.
“The goal is to enhance the diagnosis, the classification, and the treatment of depression by basically identifying evidence-based markers,” Virk said.
Currently, psychiatrists prescribe antidepressant therapy through trial and error, prescribing drugs one by one until they find one that leads to a remission of depressive symptoms. Around 30 percent to 45 percent of depressed patients attain remission with initial treatment, Virk said, while the rest remain at risk for chronic depression as well as issues like suicide, substance abuse, and other serious medical conditions.
The main problem, Virk said, is that physicians don’t know which of their patients are going to be in the population that responds to a given drug, and which are not. Resulting treatment schemes see patients cycle from one drug to another, and can be marked by side effects and poor efficacy. Read more…