Non-invasive brain stimulation and cognitive training for depressive symptoms and cancer-related cognitive impairment in breast cancer survivors (ONCODEP).

PURPOSE: Depression and cancer-related cognitive impairment (CRCI) are frequent after-effects in breast cancer survivors (BCS). Despite being closely related and sharing some features, there is no intervention addressing them comprehensively. Transcranial direct current (tDCS) and alternating stimulation (tACS), combined with computerized cognitive training (CCT), provided benefits for improving mood and cognition in several populations and have several advantages, but evidence in BCS is limited. This study aims to explore the effectiveness and feasibility of a home-based combined intervention (tDCS or tACS + CCT) to improve depressive symptoms and CRCI in BCS.

METHODS

BCS presenting depressive symptoms (Beck Depression Inventory Fast Screen >4) were randomly assigned to four groups: tDCS + CCT; tACS + CCT; sham transcranial stimulation + CCT; CCT. Home-based intervention consisted of 15 daily 20-min sessions combining prefrontal tDCS or tACS simultaneously with CCT. Linear mixed-effects models and Minimal Clinically Important Differences assessed the effectiveness of the intervention on depressive symptoms, cognitive complaints and neuropsychological performance.

RESULTS

Eighty-two BCS participated (range 46.3 - 48.9 years). Most participants completed the intervention without significant side effects. No significant differences between intervention groups were found, although improvements over time were observed across groups in depressive and cognitive outcomes.

CONCLUSION

The home-based intervention was feasible. Improvements in mood and CRCI were observed, but the additive effect of tDCS/tACS was not demonstrated. Future studies should be powered using population-specific effect sizes, consider other neuromodulation protocols and clinical outcomes and optimize home-based stimulation fidelity. The effectiveness of CCT should be further investigated.