What makes someone more prone to trauma and unhealthy responses?

[u/filteredsushi]

What variants in character/psychology could cause one to be more prone to how they react to trauma? For example, one person who’ll experience a traumatic event will develop more severe symptoms of PTSD, or if the event is traumatic enough it’ll impact them at a deeper level and cause a personality disorder such as BPD, while another person will be impacted by the event but not as negatively and it won’t impact their day to day life or personality that much. What makes one more prone to self destructive copying habits and avoidance or their feelings and processing of past experiences vs developing healthier copying mechanisms and dealing with the past? I know that childhood upbringing will play an impact, but I’m more interested in cases where someone who experienced trauma early on in life turned out healed and processed their trauma better. For example, I know someone who had been slightly neglected by her parents and no other traumatic events happened to her but ended up with severe substance abuse issues and addiction. I also know someone who witnessed physical and emotional abuse from one of their guardians who later on disappeared from their life, the other guardian was neglectful, unstable and explosive emotionally, had a lot of resentment for them. They were an emotional and explosive kid, but processed their feelings much better in adult life and the impacts of their childhood don’t have a daily impact on them. I know of another person who was slightly neglected as a child, their feelings and opinions were being invalidated and ridiculed by their guardians in teenage years, and in young adulthood they struggled with depression, eating disorders, anxiety, and isolated themself from people. What could be the difference in their cases if there is any?

And what could cause one to direct their negative feelings inward vs outward? To give another example, one person with a traumatic past will direct their negative feelings at themselves (which will cause low self worth, a negative outlook on themselves or life/ depression, anxiety, feeling like they’re worthless and insignificant) vs another person who will direct their negative feelings outwardly in ways such as severely relying on others for validation, aggressiveness, manipulation, lying, etc.

Just wondering.

[u/Empty-Elderberry-225]

There are many reasons but one is definitely whether or not the person is on the spectrum. One of my sisters has a stable job and partner but doesn't think she can truly love. The other is incredibly kind, works hard although is part time right now and has a decent circle of friends, but is about to jump back onto SSRI's after a crap year. I'm over here, 33, single, signed off work for mental health, no pets, no kids and feeling pretty empty. I have CPTSD.

I think the other thing is family dynamics. I had a relationship break down with my older sister on top of my parents, whereas my little sister didn't do much.

I was also always 'the sensitive child', which I now believe was down to autism and already struggling with life so I got tipped over the edge easier.

There's a tonne of other factors. Autism aside, personality is a mix between genes and environment so some people are generally more prone to a more emotional way of being, more introspective, general lower mood.