Your question connects well to the famous ACES study, linking early childhood trauma and other adverse childhood experiences to adult physical and mental health problems. I'd recommend reading about that study if you have not already and looking at associated links to help you.

https://www.cdc.gov/violenceprevention/aces/about.html

In terms of formulating a problem statement, you may want to pick a particular traumatic experience and a particular mental health outcome.

Does the experience of X lead to Y? You would want to specify your population and time frame too.