I am a XNFP but since I really can't peg myself as an introvert or an extrovert I tend to check both the INFP and ENFP forums a lot. I quickly noticed that the ENFP subforum was generally upbeat and cheerful whereas the INFP subforum tended to have a more melancholy vibe.
Having struggled with major depressive disorder and generalized anxiety disorder myself, I was curious as to whether there was any correlation between depression and/or anxiety and one's Myers Briggs Type. I found there was a study done on this subject and I was not surprised at the results.
The study found that patients with unipolar depression were significantly more often ISFP and INFP four-factor types. The male ISFP four-factor type was the most dramatically over-represented.
Here is the link if anyone would like to check it out: Myers Briggs Type indicator personal... [World J Biol Psychiatry. 2002] - PubMed - NCBI
This information was surprisingly very comforting to me. I have always thought of my depression as a disease, a genetic defect. Which I still believe it is. However, I felt kind of relieved knowing that the way I view the world and interact with others and feel things very deeply is somehow related to my depression. That may seem counterintuitive but to me it was as if I connected one more piece of the jigsaw puzzle together to reveal why I have been plagued with this darkness for two decades.
I hope that this information doesn't make anyone feel worse but will perhaps provide some insight instead.