My younger childhood (I am still considered a child in different situations, society, family parties, my licence...etc) was great, I played outside with my sister and neighbors all the time, didn't lose anyone, didn't notice anything wrong with my family, we moved when I was 5 so I didn't have to deal with being the new kid. My sister and I always got along well, we had our fights, but we're sisters so that's normal. My parents and I had a great relationship, talked all the time and did things together. In my mind we were almost perfect.

But, when became a teenager I started noticing how imperfect things were, family tensions, parents fighting, stuff that is normal in families. Sometimes I believe it is worse than in other families from listening to my friends families problems, but it hasn't spiraled out of control.

As to answer your questions, I think it is a mix of both. Childhood and family has an effect on someone's personality, mental health, and overall self, but I think that everyone has a chance to have mental health problems no matter how good or bad their childhood was.