"Heritability" is a misnomer. "Heritability" via twin studies cannot account for the prenatal phase, so by definition anything that results from early developmental influences is included in "heritability", where it would be more precise to regard is as environmental. Wouldn't it be weird to claim the first 9 months of plant growth is "hereditary" and has nothing to do with its environment in that phase? Epigenetics play a role in the modification of genetic markers. There is a growing body of research around cell memory and "early consciousness". Anything you can measure from a biological lense provides data for correlation, not causation. You can stop on that level, sure, and then claim that is "etiology", or you can theorize about common causes elsewhere.
Explaining "different treatments" makes it sound like there is an agreement on how to treat, say, CPTSD vs bipolar disorder vs schizophrenia vs BPD vs DID vs GAD, where in practice there is a lot of experimentation and overlap. Of course if you "treat" on the level of say, receptors, and try to influence the system that way, you need to use different drugs, depending on what effect the original cause already had. The same cause may result in different adaptations of the body for different people. If you work on the level of the psyche, you might find that what your patients have in common is a history of violence, towards self and others; the symptoms may disappear either from a continous stream of your carefully tuned drugs, or from removing the ongoing violence. Unfortunately you cannot easily measure that from the outside, and people will not necessarily give you accurate data to work with in your surveys; if you even bother to gather that. Psychotherapy is attempting to remove internalized violence against self/other.
Let me try an analogy here: You are tasked to fix broken houses. The symptom that is described is that the floors are wet and it is cold inside. You arrive at the house and see that, yes, the floor is wet, and the windows are broken; the heating works. It is not false to claim that the broken windows are the "cause" of the wet floor. You put in new windows. Case closed.
You get called to another house, with the same symptom. You find that the roof needs fixing. You create a new category in your diagnostic manual of house disorders.
You try to approach it scientifically: You take the symptoms of 100.000 houses, and categorize measurable problems inside the house and correlate them to what needs to be fixed. You may in fact not be interested in why the windows are broken: You make a living from these repairs. You do sometimes wonder why you get called to the same houses periodically to find the same windows broken, but you don't see anything particularly wrong with the house after you fix it up each time so you move on. It's not your job to identify a group of youngsters that walk around throwing rocks into people's windows and dismantling roofs.
Is it wrong to claim that fixing the windows is the correct treatment at the "origin", and that it wouldn't help if the roof needs fixing? No. Does it say anything about the "root cause"? No.
DSM Disorders Disappear in Statistical Clustering of Psychiatric Symptoms (2024)
https://www.psychiatrymargins.com/p/traditional-dsm-disorder...