Non-Invasive Brain Stimulation and Cognitive Training for Depressive Symptomatology Related to Breast Cancer (ONCODEP)

The goal of this clinical trial is to test a home-delivered intervention that combines Non-Invasive Brain Stimulation techniques (transcranial direct and alternating current stimulation -tDCS and tACS-) and Online Cognitive Training (OCT) to treat depressive symptomatology and cognitive decline associated with breast cancer. The main questions aims to be answered are: * To analyze the efficacy and feasibility of the intervention to treat depressive symptomatology. * To analyze the efficacy and feasibility of the intervention to treat cognitive decline. * To evaluate the medium and long-term effects (1, 3 and 6 months) of intervention. An OCT program and a portable wireless tDCS/tACS system will be used to perform the intervention at home. Patients will be divided into four treatment groups, depending on whether they will receive the OCT applied independently or combined with tDCS/tACS active or sham. In addition, saliva samples will be collected to identify bomarkers predictive of treatment efficacy.