Effects of virtual reality-based cognitive training on working memory and frontotemporal lobe in patients with major depressive disorder: A randomized controlled study.

BACKGROUND

Most patients with major depressive disorder (MDD) have working memory (WM) impairment, which can be improved by virtual reality-based working memory (VR-WM) training; however, the specific neural mechanisms remain unclear. This study aimed to clarify how VR-WM training improves WM in patients with MDD and further explore the role of the frontotemporal lobe in related neural mechanisms.

METHODS

A total of 57 patients with MDD were included in a randomized controlled study to clarify the effects of 20 sessions of VR-WM training on WM in patients with MDD and to explore the role of the frontotemporal lobe in associated neural mechanisms. The Stroop color word test, 2-back task, digit task switching, and digit span test were used to measure the inhibition, updating and switching functions of WM and WM span. The functional features of the frontotemporal lobe in patients with MDD at rest were detected using functional near-infrared spectroscopy before and after training.

RESULTS

After VR-WM training, patients with MDD exhibited significant improvements in the accuracy of the Stroop color word test (p = 0.013) and 2-back task (p = 0.002), the scores of digit span test (p = 0.030) and Hamilton Depression Rating Scale (HDRS) score (p = 0.006). Significant group-by-time interactions of local efficiency (p = 0.005) and clustering coefficient (p = 0.004) of the frontotemporal lobe were observed between groups. The degree of improvement in the total score of the digit span test was positively correlated with the change in the clustering coefficient (p = 0.034).

CONCLUSIONS

VR-WM training effectively improved inhibition, updating and memory span in the WM of patients with MDD. Furthermore, VR-WM training was observed to enhance functional connectivity in the frontotemporal lobe, thereby improving WM performance in patients with MDD.