I talked with my therapist about this. High functioning means you are able to care for yourself, eat shower etc. I believe no alcohol/ drug issues but honestly not certain. It also includes being able to hold down a job, not necessarily the one you want or trained for, but any job. How I look at it, most people do not know I am bipolar. i am generally able to hide it. So when I am struggling I am not taken seriously because it does not look like anything is wrong.