I always wondered that too but yes genetics can be a big part. Mental illness can be as strong as color of your eyes and hair color and height from your parents. I say just talk to your parents about mental health or anything you might be going through and see if they can relate. But yah I always wondered that too . But mental health can be seen in the brain but a for sure thing about really knowing if you have one is talking to people who study them. And basically talking is a sure fact of getting a diagnosis and also even researching things yourself and tik tok helps too so many videos about mental illness :)