To understand the situation well, we must begin with the premise that humans are created with a certain architecture, designed to interact with cosmic forces and the universe, including other humans.

The body is a transceiver and effector of the mind. Each body transceives and effects a network of nodes called 'psychons' described in and on the mind space.

Now each body organ is linked to these networks via memory. When memories are triggered, certain neural pathways are exited to certain frequencies. And as electrons are fired, the resultant photons converge and resonate with that body's psychon system.

The result is a computation in the mind system that generally traces a networked path. That path begins from the transceiver and terminates the same. That is, via psychons which, are connected to bunches of dendrites called 'dendrons'.

These dendrons being part of the neural pathways effect the behavior prescribed by the mind computation.

So, that in effect means that the body system sends queries related to contexts, and the mind, depending on memories stored, sends responses that describe human behavior.

If you can understand up to this point, then we can understand most if not all human behavior.

You're doing great.

Only 'PTSD' is a term describing behavior that's a response to a query.

So what matters is the context of the query, the external forces involved, and a set of desired equilibrium states of the person(s) involved.

The basic unit of a context is a 'game'. Before we understand the game an individual is playing in, the players involved and the initial conditions of the game and players, then we can't say what is causing the behavior.

Each illness is as unique as the individual experiencing it.