Establishing which came first or if one caused the other and why can be difficult
The term "co-morbid" has three definitions:
to indicate a medical condition existing simultaneously but independently with another condition in a patient (this is the older and more "correct" definition)
to indicate a medical condition in a patient that causes, is caused by, or is otherwise related to another condition in the same patient (this is a newer, non-standard definition and less well-accepted).
to indicate two or more medical conditions existing simultaneously regardless of their causal relationship
I can tell you from personal experience that being in very stressful, life threatening situations can cause all kinds of "abnormal" responses from individuals ranging from "heroic" to complete "meltdowns". Every person reacts differently. It's not an excuse for threatening someone but it is a very plausible explanation.
You tube video/documentary.
Shell Shock 1914-18
So you do not cite any reference for your defiinitions yet you acknowledge that the so called ‘new’ definition is not accepted....Your logic is flawed at best.
Saying that people react to stressors differently is a no brainer