Although depression can be a frighteningly relentless condition, there is hope in the form of ongoing research into novel treatment options, particularly for those with treatment-resistant depression.
The prevalence of treatment-resistant depression is similar in older and younger individuals. However, since it appears to hasten cognitive decline, it is crucial to find more efficient methods of managing it.
A recent study conducted by Washington University School of Medicine in St. Louis found that for older adults suffering from clinical depression that is unresponsive to conventional therapies, augmenting their existing antidepressant regimen with aripiprazole (marketed under the brand name Abilify) is more successful than switching to a different antidepressant.
The FDA first authorized aripiprazole in 2002 as a treatment for schizophrenia, but it has also been used at lower dosages as an add-on therapy for severe depression in younger patients who do not respond to antidepressants alone.
Today, The New England Journal of Medicine released the latest findings, which will also be presented by Eric J. Lenze, MD, the lead investigator and head of the Psychiatry Department at Washington University, and his team during the annual conference of the American Association for Geriatric Psychiatry in New Orleans.
Many individuals with clinical depression may not respond to antidepressant medicines. As a result, some medical professionals change these patients’ antidepressants in an effort to discover one that works, while others may recommend a new class of medicine to see whether a combination of meds helps.
These approaches have been suggested by experts as potential treatments for older persons with depression that has resisted therapy. The goal of the new research was to identify the most successful method.
According to the study’s findings, adding aripiprazole to an antidepressant improved the condition of 30% of patients with treatment-resistant depression compared to just 20% of those who switched to another antidepressant alone.
Correcponding author Lenze says that “we found that adding aripiprazole led to higher rates of depression remission and greater improvements in psychological well-being — which means how positive and satisfied patients felt — and this is good news.
“However, even that approach helped only about 30% of people in the study with treatment-resistant depression, underscoring the need to find and develop more effective treatments that can help more people.”
There is no difference in the prevalence of treatment-resistant depression between older and younger individuals, but since it seems to exacerbate cognitive deterioration, it is crucial to develop more effective treatments.
Lenze and colleagues from Columbia University, UCLA, the University of Pittsburgh, and the University of Toronto evaluated 742 persons aged 60 and above who had treatment-resistant depression, defined as not responding to at least two different antidepressant drugs.
The study was divided into two independent stages as the researchers investigated treatments for older patients’ treatment-resistant depression that are often used in clinical practice. In the first phase, 619 people who were taking an antidepressant like Prozac, Lexapro, or Zoloft were put into three groups at random. Patients in the first group got the medication aripiprazole (Abilify) along with whichever antidepressant they were previously taking. A second group maintained taking antidepressants but added bupropion (Wellbutrin or Zyban), while a third group tapered off the antidepressant they were taking and switched to bupropion.
Over the course of 10 weeks, study clinicians called the participants every two weeks or met with them in person. During these visits, the medications were changed based on how each patient responded to them and how they made them feel. The group of patients who maintained taking their initial antidepressants while also taking aripiprazole had the greatest overall results, the researchers discovered.
The researchers expected that some individuals might not react to the different treatments, so they introduced a second phase with 248 participants. During this phase, patients on antidepressants such as Prozac, Lexapro, and Zoloft were treated with lithium or nortriptyline – drugs that were frequently used before the approval of these other, more recent antidepressants more than two decades ago. In the second phase of the trial, depression relief rates were poor, at roughly 15%. Neither lithium augmentation nor switching to nortriptyline had an obvious advantage.
Lenze explained that older drugs are more complex to use than newer treatments. For instance, the use of lithium requires regular blood testing to ensure its safety, and patients taking nortriptyline are advised to receive periodic electrocardiograms to monitor their heart’s electrical activity. However, as neither lithium nor nortriptyline has shown promise in treating treatment-resistant depression in older adults, they are unlikely to be helpful in most cases.
But even the best way to treat depression, which was to add aripiprazole to an antidepressant, did not help many older people with depression that did not respond to treatment.
“This really highlights a continuing problem in our field,” adds senior author Jordan F. Karp. “Any given treatment is likely to help only a subset of people, and ideally, we would like to know, in advance, who is most likely to be helped, but we still don’t know how to determine that.”
Antidepressants are often quite beneficial for the majority of patients who are experiencing clinical depression, according to Lenze. At least half of all depressed individuals see significant improvement after starting the first medicine they try. Yet almost half of the remaining patients who were not helped by the first medication get better when transferred to the second medication, leaving a sizable group of patients with clinical depression who do not react to both therapies.
The issue is especially challenging for older folks since many of them are already taking many drugs for other ailments including high blood pressure, heart problems, or diabetes, according to Lenze. Hence, adding more psychiatric medications or switching to new antidepressants every few weeks might be challenging. Finding more efficient therapeutic approaches is also essential since depression and anxiety in older persons may hasten cognitive deterioration.
“There definitely is something that makes depression harder to treat in this population, a population that’s only going to keep getting larger as our society gets older,” he adds.
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