Cognitive control training as an add-on treatment for late-life depression: A multicenter randomized controlled trial

Late-life depression (LLD) is a prevalent and debilitating condition associated with a poor long-term prognosis and high rates of chronicity. Cognitive control impairments are common in LLD and contribute to symptom persistence, yet they are not sufficiently targeted by standard treatments. We investigated whether adding a brief Cognitive Control Training (CCT) program to treatment as usual (TAU) improved outcomes in older adults with LLD.

In this multicenter, single blind randomized controlled trial, 90 older adults diagnosed with LLD were randomized to eight sessions of CCT (N = 49) or an active control training (ACT; N = 41) over four weeks, in addition to TAU. Assessments were conducted at baseline, post training (approximately one month after baseline), and at three-, six- and twelve month follow-up. The primary outcome was self-reported depressive symptoms, and secondary outcomes included rumination, emotion regulation strategy use, and cognitive functioning.

A mixed-effects model revealed no significant difference in the reduction of depressive symptoms between the CCT and ACT conditions over the twelve-month follow-up period. Both conditions improved on symptom severity, but no significant differences were found for any of the secondary outcomes.

Contrary to our hypothesis, CCT did not yield more clinical improvement in depressive or cognitive outcomes in older adults. Potential explanations include suboptimal intervention dose/intensity, age-related reductions in neural plasticity and processing speed that may limit trainability, and high baseline severity and multimorbidity typical of specialized care.

In this multicenter trial, adding CCT to TAU did not confer clinical benefits for late-life depression. Future research should investigate different dosage strategies and identify patient subgroups most likely to benefit.