The most intense attachment injury trauma occurs between 0-3. Here’s an anecdotal experience- old client of mine who has a daughter with severe mental illness can trace it back to singular event. My client had recently given birth and wanted to take her daughter to see family in Portugal. She was staying in a hotel with her daughter and was raped. After the attack the baby kept crying and she remembers picking the baby up, screaming at her, and throwing her back into the crib. For days she couldn’t do anything above keeping her alive. Soon the connection healed but the damage was done. The terror and fear of abandonment when we are in our most vulnerable faze of life is utterly frightening to imagine. Of course other variable impact our mental health as we mature. Some are just plainly unlikely when it comes to genetics, but most suffering from chronic mental illness are chronic because they are unable to create healthy attachment with other people. I dislike the term mental illness, we are all wild animals penned into a society that doesn’t resonate with our instincts and values. This is just my opinion, I’m not making a judgment about your experience