If I Stop Accutane After 3 Months, if I Were to Restart It, Do I Pick Up Where I Left Off? Or Start All over Again?

I stopped taking Accutane after being on it for about 3 months. I stopped due to severe side effects. My acne has improved, but not as much as I'd like. If I were to start taking Accutane again would I pick up where I left off (be on it for three more months) or would I have to start all over again and be on it for 6 months or so?