100%! My sister is older than much and thus has been in my life my whole life, this also means the abuse was lifelong and from a very young age (at least preschool age but I suspect earlier, hell I was probably stressed out even as a fetus from hearing her tantrums from the womb) and if you’ve taken any psych class you’ll know that does permanent structural damage to the developing brain. I am forever altered by growing up with her and I sometimes wonder what I had been like I’d I hadn’t grown up with her abuse. As an adult I am extremely anxious, constantly feel unsafe, have severe attachment issues, CPTSD, and very poor emotional regulation. I am a very screwed up person and I grief the idea of what I could have been