Cognitive training with and without transcranial direct current stimulation in older adults with HIV-related cognitive deficits: Delayed impact on mood

Abstract

Abstract In a study of computer-delivered cognitive training with and without transcranial direct current stimulation (tDCS) compared to a control, we assessed 46 participants' mood before treatment, immediately after completing six 20-minute treatment sessions over two weeks, and then again one month later. Participants were persons 50 years of age and older with HIV-associated neurocognitive disorder confirmed based on their performance on a battery of neuropsychological measures. Participants were randomly assigned to receive (1) active tDCS with computer cognitive training (a game-based intervention), (2) sham tDCS with cognitive training, or (3) sham tDCS with watching educational videos as a control. Analyses were completed using mixed-effects models computed in R. Participants who received active treatments showed moderate to large treatment effects, especially in the areas of attention and response inhibition. Participants in all groups showed modest improvement in mood, but group differences did not emerge at initial follow up. At one-month follow-up, participants who received cognitive training and active tDCS reported substantial declines in depressive symptoms compared to those who received only training or those in the control group. This finding is consistent with a delayed response to the mood-improving impact of tDCS observed in other studies. This finding suggests the importance of observing the impact of tDCS with cognitive training over at least several weeks of treatment and the need to provide adequate follow-up in assessing treatment effects. Keywords: HIV, computer based cognitive training, HIV associated neurocognitive disorder