The most profound and simple way I've learned to explain depression I learned from an Andrew Solomon quote in the PBS documentary Depression: Out of the Shadows -

'The opposite of depression isn't happiness. It's vitality.'

It's important to have the proper language and understanding in order to communicate effectively on the subject of mental health. With that in mind, here are a few pieces I've written on the matter of mental illness, if you want to have a look.

https://medium.com/happily-faithless/cursed-unto-the-third-and-fourth-generation-98816b9acd41

https://darhtbjehl.medium.com/every-molehill-is-an-everest-a-brief-primer-on-depression-and-the-brain-fdc0291b5f31

https://darhtbjehl.medium.com/and-we-talked-and-talked-and-talked-and-talked-f339660956cd