The symptoms of a mental illness can overlap with normal variations of personality. It is very important to note this is overlap, *not* a spectrum! A person’s

The symptoms of a mental illness can overlap with normal variations of personality. It is very important to note this is overlap, *not* a spectrum! A person’s baseline can be altered by mental illness but not severely enough to be indistinguishable from a personality difference. Telling the two apart is damn near impossible. Since we don’t have blood tests, we cannot tell the difference. So we need to fall back on want little objective criteria can be found. Behavioral criteria can be skewed due to environment. An active kid who wants to run around isn’t going to do well being stuck in a classroom for six hours. A curious kid with ADHD, who would otherwise be a good student also won’t do well because they can’t stay on task. These look identical. (This is why ADHD is both over and under diagnosed.) This results in family history and quality of life being more objective than self-reported feelings.