One in 10 Americans take antidepressant medication. (Photo: Stocksy/Guille Faingold)
In paradox that could help explain why about one third of American’s approximately 25 million depression sufferers don’t respond to their medication, a new study has found that more than 80 percent of people with depression wouldn’t be eligible for clinical trials of depression medication.
The research, published in the Journal of Psychiatric Practice, involved more than 4,000 U.S. adults with moderate to severe depression. Researchers took the broad sample of depression suffers and applied common criteria used to determine whether or not someone is eligible for an antidepressant medication study.
Overall, the vast majority of people with depression would be left out of antidepressant trials, the study found. Specifically:
- 20 percent would be excluded because of a significant medical condition, such as a recent stroke
- 15 percent would be excluded because their depression wasn’t severe enough
- 14 percent would be excluded because they were older than 65
- 21 percent of women would be excluded because they weren’t on birth control
There are good reasons why clinical trials exclude certain patients, says study author Matthew Macaluso, D.O., of the University of Kansas School of Medicine-Wichita. “The criteria exist to protect subjects and maximize a study’s ability to find a signal by minimizing noise,” Macaluso tells Yahoo Health. By cutting out factors that might affect depression outcomes or how a drug works, researchers are better able to zero in on the medication’s actual effects.
But there are obvious drawbacks, too, Macaluso adds: “Inclusion and exclusion criteria create a rarefied population of patients with a given illness in clinical trials.” In other words, the group testing an antidepressant medication isn’t an accurate representation of people living with depression.
“This means that results of the study may not be generalizable to the total population of individuals with that illness,” Macaluso explains, adding that the criteria do tend to expand and include more people once more is known about a drug.
It’s well-known that some patients have more success with antidepressant medications than other people. Robert Winston, M.D., a psychiatrist with Gelbart and Associates, says that individual differences in genetic programming, brain chemistry, and biological responses to medication all affect how well an antidepressant medication works from one person to another.
“In my 30 years of practice, I’ve consistently found that about one-third of patients get complete relief of depressive symptoms from medication, one-third have significant improvement, and one-third have little effect and continue to struggle,” Winston tells Yahoo Health. He adds that depression patients tend to see the greatest relief with a combination of medication and talk therapy (such as counseling or psychotherapy).
Moe Gelbert, Ph.D., a psychologist with Torrance Memorial Medical Center, encourages people with depression to seek counseling, improve their health habits (such as sleep, exercise, and nutrition), and cultivate supportive relationships. If you think you may be depressed, talking with your primary care doctor is a good first step to find the right treatment for you and start feeling better.
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