In other, more blunt terms, is this a "hardware" or a "software" issue?
However the following articles' descriptions of drug treatments using alpha-agonists, such as clonidine and guanfacine, which provide a response rate of 55% (significant relief for 55% of people) does imply to me that there is some physiological basis and may be of interest to people reading this thread: https://neurodivergentinsights.com/how-to-deal-with-rejectio... https://neurodivergentinsights.com/history-of-rejection-sens... https://www.goldstarrehab.com/parent-resources/is-rejection-...
And I think there are stronger findings that autism/ADHD is at least partially genetic.
P.S. I would caution you against holding a premise of a hard "or", that mental conditions are either hardware or software, or the hidden premise that you can't patch hardware with software.