Investigating Differences in Brain Connectivity Between Active VS Sham Transcranial Direct Current Stimulation Groups in the Mindful Breathing Task
Depression is a serious psychological disorder affecting many adolescents/young adults. Rumination involves repetitive, automatic negative thoughts and is a key feature in depression. The brain region that is associated with rumination is the default mode network (DMN). DMN is associated with mind-wandering and self-related thoughts. The dorsolateral prefrontal cortex (DLPFC) functions in regulation/cognitive control and regulates the mind-wandering aspect of the default mode network. The DMN-DLPFC connectivity is reduced in depression because the DLPFC is hypoactive and cannot regulate the overactive DMN from automatic negative thoughts. Mindful breathing training is a mindfulness practice that focuses on present events and breathing. Theoretically, when applied to ruminating depressive people, it allows disengagement from repetitive negative thoughts. Transcranial direct current stimulation (tDCS) is a type of neuromodulation that uses electrical stimulation to alter brain activity. If stimulated the under-connected DMN-DLPFC in depression addresses the neural issue, and mindful breathing training addresses the behavioral issue. This should provide a better treatment for depression together rather than by itself. Participants were randomized to receive active or sham tDCS. Sham was the control group, and only received stimulation for a little bit in the beginning and end of the session. Active group received stimulation the whole session. Overall, the whole group analysis showed a significant decrease in depression from baseline to post treatment. No significant differences in the relationship between DMN-DLPFC connectivity and changes in depression. Mindful breathing training seems to be an effective intervention for depression on its own.