I found this Science Daily adaptation of a news release issued by the NIH...

Scientists are using a virtual-reality, three-dimensional video game that challenges spatial memory as a new tool for assessing the link between depression and the hippocampus, the brain's memory hub. Spatial memory is the memory of how things are oriented in space and how to get to them. Researchers found that depressed people performed poorly on the video game compared with nondepressed people, suggesting that their hippocampi were not working properly.

So, it is all in my head?