Depression appears to cause changes to the structure of the brain, as well as the other way around. That may be due to behaviour changes that can shrink unused brain pathways
Source:
https://www.newscientist.com/article/2219478-depression-may-reduce-the-amount-of-white-matter-in-the-brain/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home