Epigenetic Enhancement of Cognitive Training in Aging Mood Disorder Populations

The aim of this clinical trial is to investigate the effects of a three-week virtual reality-based cognitive remediation training (VR-CRT) programme in combination with daily intake of a histone deacetylase inhibitor (HDACi) sodium butyrate on cognition in symptomatically stable patients with mood disorders (depression or bipolar disorder). The investigators hypothesize that the VR-based cognitive remediation training (VR-CRT) combined with HDACi butyrate vs. a VR-based control treatment combined with placebo will improve global cognition (primary outcome measure) over three weeks. Secondly, the investigators hypothesize that VR-CRT with placebo will improve cognition relative to the VR control treatment with placebo, although to a lesser extent than VR-CRT with HDACi butyrate. Thirdly, the investigators hypothesize that the HDACi butyrate with VR control treatment will not produce cognitive improvements relative to placebo with VR control treatment. Finally, the investigators hypothesize that the combined treatment (VR-CRT + HDACi butyrate) will enhance neuroplasticity (exploratory outcome) vs. VR control with placebo, as indicated by increase in hippocampal volume and/or memory-related activity shown with structural and functional MRI.