But to your point, there are well-described genetic risk factors. And socioeconomic, environmental, etc. risk factors. Like any complex behavior, there's no "one weird trick" that explains it all. But that doesn't get clicks. (I am an MD who treats addiction)
MAOIs are good for getting people out of bed while their team figures out what other sorts of interventions they'd benefit from:
[...] New research into MAOIs indicates
that much of the concern over their
supposed dangerous dietary side
effects stems from misconceptions
and misinformation, and that it is
still underutilized despite
demonstrated efficacy.[4] New
research also questions the
validity of the perceived severity
of dietary reactions, which has
been based on outdated research.
[0] https://en.wikipedia.org/wiki/Monoamine_oxidase_inhibitorLater anti-depressants (Tri-cyclics, SSRIs, etc) tended to be less-effective than the MAOIs, but the MAOI's patents had expired.
B-vitamins can boost the metabolism. There's a prescription version of Methyl-Folate that's approved as an add-on for depression treatment (imho, this vitamin should really be a primary treatment).
There's lots of space for the medical perspective on a treatment team.
Research into my own family has convinced me that the cultural conditioning is a huge factor. Key data points for me were seeing some very specific behavior patterns replicated across generations by certain women in my family. I just can’t explain that level of “copycat” behavior with a gene.
http://www.els.net/WileyCDA/ElsArticle/refId-a0005230.html
Not that genetics are the only factor.