Summary
Background
Treatment-resistant major depressive disorder is common and potentially life-threatening in older persons, in whom little is known about the benefits and risks of augmentation pharmacotherapy.
Methods
We conducted a multi-site, placebo-controlled, randomized clinical trial to test the efficacy and safety of aripiprazole augmentation for older adults with treatment-resistant depression. We treated 468 participants aged 60 and older with current major depressive episode with venlafaxine extended-release (ER); 96 (20.5%) did not complete this open phase, 191 (40.8%) remitted, and 181 (38.7%) did not remit and were randomized to 12 weeks of double-blind augmentation with aripiprazole or placebo. The computer-generated randomization was done in blocks and stratified by site. The primary endpoint was remission, defined as Montgomery-Asberg Depression Rating Scale scores ≤10 (and at least two points below the score at the start of the randomized phase) at both of the final two consecutive visits. We also assessed resolution of suicidal ideation, and safety and tolerability with cardiometabolic and neurological measures. Analyses were conducted according to the intention-to-treat principle. This trial is registered with ClinicalTrials.gov, number NCT00892047.
Findings
Older adults on aripiprazole had a higher remission rate than those on placebo (44% versus 29%; odds ratio [OR]=2.0, 95% CI 1.1–3.7, p=0.03; number needed to treat [NNT]=6.6 [95% CI 3.5–81.8]). Overall, remission was stable during 12 additional weeks of continuation treatment. The resolution of suicidal ideation was more marked with aripiprazole than with placebo. Akathisia was the most common adverse effect (27% of participants on aripiprazole). Compared to placebo, aripiprazole was also associated with more Parkinsonism but not with treatment-emergent suicidal ideation, QTc prolongation, or increases in adiposity, glucose, insulin, or lipids.
Interpretation
In older adults who fail to achieve remission from depression with a first-line antidepressant, the addition of aripiprazole is effective in achieving and sustaining remission. Tolerability concerns include potential for akathisia and Parkinsonism.
Funding
National Institute of Mental Health, UPMC Endowment in Geriatric Psychiatry, Taylor Family Institute for Innovative Psychiatric Research, National Center for Advancing Translational Sciences, and the Campbell Family Mental Health Research Institute.