It does get pretty tiring explaining the difference between them. Mine is definitely biologically based, although stress exacerbates it like it does many other things like acne. My &quot;eureka&quot; moment came in high school (when brain chemistry changes from puberty can cause such issues). I was at home playing video games online with friends when I noticed my vision was blurry. I went to the bathroom and saw tears streaming down my face, which baffled me as my conscious thoughts were in no way sad&#x2F;negative at the time. There was just an underlying feeling of heartache. Over the next 4-5 years I worked with a professional and finally managed to find a drug combo that balances me out. I still get sad, but only for logical reasons, and only as much as I used to before my symptoms developed. It has been a full year for me now without any &quot;episodes&quot;, something I had not thought possible previously. I just figured I would share this in case someone else might benefit from reading it.