NEW ORLEANS –
“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,” study investigator Eric J. Lenze, MD, of the department of psychiatry, Washington University, St. Louis, said in a press statement.
“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,” he added.
The findings were presented here as part of the American Association for Geriatric Psychiatry annual meeting, and published concurrently in the New England Journal of Medicine.
Need for safe treatment options
Treatment-resistant depression is common in older patients, but switching medications or adding other agents can be challenging. With higher rates of comorbidity and polypharmacy, treatment decisions in this patient population are more complex compared with those involving younger patients.
To compare the benefits of augmentation vs. drug-switching strategies, the researchers conducted a multicenter, two-step trial involving 619 patients with an average baseline age of 69 who had failed to respond to two courses of selective serotonin reuptake inhibitors (SSRIs).
Patients were randomly assigned to one of three groups. These included augmentation of existing antidepressant medication with either aripiprazole (n = 211) or the dopamine and norepinephrine–reuptake inhibitor bupropion (Wellbutrin, Zyban) (n = 206), or to taper off of their current antidepressant and switch to bupropion (n = 202).
After 10 weeks, patients’ psychological well-being was assessed via the National Institutes of Health Toolbox Positive Affect and General Life Satisfaction subscales. The researchers found patients in the aripiprazole and bupropion add-on groups improved by 4.83 points and 4.33 points, respectively. The bupropion switch group had a change of 2.04 points.
The difference between the aripiprazole augmentation group and the switch to bupropion group was significant (difference 2.79 points; P = .014). Other between-group differences were not significantly different.
Remission rates were similar in the aripiprazole and bupropion groups at 28.9% and 28.2%, respectively. The remission rate in the bupropion switch group was 19.3%.
The study results showed patients who received adjunctive bupropion had the highest fall rate at 0.55 falls per patient, vs. 0.33 falls per patient in the aripiprazole group, suggesting that among the three treatment options, adjunctive aripiprazole may be the best choice because of its superior efficacy and lower fall risk.
A total of 248 patients enrolled in the study showed no improvement and were further randomly assigned to receive adjunctive lithium (n = 127) or switch from current therapy to nortriptyline (n = 121).
Well-being scores in the lithium group improved by 3.17 points and 2.18 points in the nortriptyline group. Remission occurred in 18.9% of patients in the lithium group and 21.5% in the nortriptyline group. Fall rates were similar among the two groups.
Overall, “this large, randomized study demonstrated that adding aripiprazole was a superior option for older adults with treatment-resistant depression,” Dr. Lenze told this news organization.
“Since neither lithium nor nortriptyline were promising against treatment-resistant depression in older adults, those medications are unlikely to be helpful in most cases,” he added.
In an accompanying editorial, Gemma Lewis, PhD, and Glyn Lewis, PhD, division of psychiatry, University of College London, noted the findings “support aripiprazole augmentation as a strategy for treatment-resistant depression in older persons, largely because of the lower risk of falls than with bupropion augmentation.”
However, “in clinical practice, [it] would be important to tailor treatment in light of potential adverse effects and the preferences of the patient,” they added.
Akathisia, for instance, is a common side effect of aripiprazole, shown in one recent trial to affect 11% of the patients. In addition, weight gain, though typically lower than seen with other antipsychotics, is a consideration with aripiprazole.
With respect to fall risk, they noted that bupropion was largely used in relatively high doses of 300 mg and 450 mg, despite some recent research showing little clinical benefit from increasing antidepressant doses above minimum recommendations.
“It is possible that smaller doses of bupropion than those used in the current trial would retain effectiveness while minimizing adverse effects such as falls,” the editorialists noted.
Commenting on the study, Jennifer R. Gatchel, MD, PhD, assistant psychiatrist at Massachusetts General Hospital/McLean Hospital and assistant professor of psychiatry at Harvard Medical School, Boston, said the findings have high clinical significance in the treatment of geriatric depression.
“These results are of great impact for clinicians managing older adults with treatment-resistant depression. They provide some of the first evidence of safety and efficacy of augmentation with aripiprazole as a strategy in clinical management of older adults who fail to initially respond to treatment,” said Dr. Gatchel, who was not associated with this research.
“Of particular significance, efficacy here is based on patient-centered outcomes and psychological well-being as a primary effectiveness outcome, which could translate into strengthened physician-patient alliance.”
While adjunctive aripiprazole is not necessarily a first-line strategy when older adults fail to respond to antidepressants, there is a lack of data on the risks and benefits of any other antipsychotic medications, she noted.
“Thus, this is evidence that will impact clinical practice and hopefully contribute to reduced societal burden of depression in older adults and the morbidity and mortality associated with it,” Dr. Gatchel said.
The study received support from a Patient-Centered Outcomes Research Institute (PCORI) Award (TRD-1511-33321). Dr. Lenze received additional support from the Taylor Family Institute for Innovative Psychiatric Research at Washington University School of Medicine, as well as the Washington University Institute of Clinical and Translational Sciences grant (UL1TR002345) from the National Center for Advancing Translational Sciences of the National Institutes of Health. Dr. Gatchel reports no relevant financial relationships.
A version of this article first appeared on Medscape.com.