Studies show that over half of older adults with clinical depression are largely unresponsive to the standard therapeutic interventions commonly used to treat this condition. Findings from a new paper, published in the leading medical journal Lancet, however, has found that adding a second drug – an antipsychotic medication – to the treatment regimen can make the outcome substantially better.
Previous research has already shown that the combination of an antidepressant and a low dose of aripiprazole (brand name Abilify) was effective at alleviating the symptoms of depression in younger adults, but since older patients may not necessarily respond to treatments that work for someone half their age, more studies were sorely needed.
“This is a rare study because it looks at depression specifically in older adults,” said Benoit H. Mulsant, MD, a co-author on the study and a senior scientist at CAMH in Toronto. “It’s important to treat older adults for depression, especially given that adults with late-life depression are at an increased risk of developing dementia. But this research demonstrates that older adults do respond to depression therapy.”
In the study, conducted in several health care centres in the US and Canada, and involving 468 people over the age of 60, participants received an extended-release formulation of the antidepressant drug venlafaxine (brand name Effexor XR) for 12 weeks. At the end of the trial, about half of them were still depressed.
The second part of the study had non-responders keep taking venlafaxine, but added either a low dose of aripiprazole (a drug sometimes used in treating schizophrenia and bipolar disorder) or a placebo. This resulted in a 44 percent response rate in the intervention group, compared to only 29 percent in those who received the sugar pill.
According to Charles F. Reynolds III, MD, a Geriatric Psychiatrist at the University of Pittsburgh, the coordinating site for the study, these findings constitute a major advance in support of evidence-based care for older adults with depression.
“By publishing our findings in the Lancet, we hope particularly to reach primary care physicians, who provide most of the treatment for depressed older adults. The excellent safety and tolerability profile of aripiprazole, as well as its efficacy, should support its use in primary care, with appropriate medical monitoring.”
Some of the patients receiving the drug combo did experience side effects, but in most cases they were mild and short lived. None of the problems often associated with antipsychotic medication, such as weight gain and metabolic dysfunction, were observed, and the benefits of such an approach far outweighed the side effects.
The key remaining question to answer next is who responds to the intervention and who doesn’t. “One of the things we see as critical to our future research will be trying to better understand the factors that make some people respond to specific forms of treatment that may not work for others,” concluded first author Eric J. Lenze from the University of Washington.