Two recent studies examining the effects of antidepressants have put Penn at the forefront of controversy over antidepressant efficacy and outcomes.
Robert DeRubeis, a psychology professor at Penn, was a key author in both studies.
One study, published this year by DeRubeis in the Journal of the American Medical Association, has created a significant amount of controversy both in the mainstream press and in medical circles.
The study showed that paroxetine and imipramine, two commonly-prescribed antidepressants, were only slightly more beneficial than placebos in treating patients with mild and moderate depression.
Despite the strong reactions to the JAMA study, DeRubeis insists that the results should be considered within the context of previous research.
“No one had ever published an estimate of the benefits of antidepressant drugs for mild and moderate depression compared to placebo,” he said.
“We did find the usual benefit of medicine over placebo in the more severely depressed group,” he explained.
Michael Detke, a Penn alumnus and the chief medical officer of MedAvante, a company which evaluates mental-health trials, noted that the JAMA study’s failure to observe antidepressant efficacy in mild and moderately depressed individuals could have occurred for many reasons, including variability among patients and their day-to-day symptoms.
“The JAMA study failed to show that antidepressants are effective in more mildly ill patients. It did not demonstrate that they are ineffective,” he wrote in an e-mail. “Absence of evidence is not evidence of absence.”
Detke referenced a Harvard University and World Health Organization study that ranked depression as the second highest cause of disability in first-world countries.
“We should be very cautious about messages that suggest that we should reduce treatment,” he wrote.
“One good effect of this study is that it is causing doctors around the country to talk about prescribing practices” on mild and moderate depression cases, DeRubeis said.
DeRubeis’ earlier study, published in December 2009 in the Archives of General Psychiatry in collaboration with researchers from Northwestern and Vanderbilt Universities, examined the effects of paroxetine on personality risk factors linked with depression, such as neuroticism.
While the earlier study published in the Archives has received less press attention, Detke wrote that “this was one of the more interesting clinical trial findings I read in some time.”
The Archives study showed that paroxetine — commonly sold under the brand Paxil — has significant advantages over placebos in changing personality, even more so than its effects on actual depression symptoms.
The study showed that patients taking paroxetine who exhibited reduced neuroticism — a personality trait reflecting a tendency to react strongly to negative events — were also less likely to experience a depression relapse.
“This is the first hint in any human data that there could be enduring effects that result from being on these antidepressants,” DeRubeis said.
Regarding the Archives study, Detke wrote, “It either means that antidepressants really work on different aspects of our psyches than we all have thought, or that there’s not such a divide between personality factors and some illnesses.”
DeRubeis noted that a decrease in neurotic symptoms in patients does not necessarily directly affect their depression symptoms. However, it does affect personality factors that could cause them to be at a greater risk for depression.
