This seems similar, I've always been hesitant to explain exactly why I took such a long sabbatical since I didn't want to give the impression I could burnout with another employer (not the main reason but it was a big one). I haven't explained during interviews the lessons I learned as a result of leaving and how to prevent something similar in the future. Thanks for sharing!

Good idea about addressing it in my cover letter, I'll go ahead and do that. To be honest it does look on paper that I wasted my time and didn't do much to keep my skills up, a lot of my time was focused on improving my mental health (I did some things here and there but they're pretty sparse relative to the ~1.5 yr gap in total). My biggest concern is that my resume doesn't have an upward trend in terms of career progress...I graduated from a top university with a decent gpa, worked soon after graduation, last job as an automation engineer...then nothing

@TheDemonLord Recently I did a Coursera course and two projects, I've listed them on my resume. The issue is that I did that over the last few months. For about a year I honestly didn't do much of anything productive due to mental health issues. The ~1.5 year gap is pretty big and I'm not sure how to address that.