One of the downsides of adhd is, if left untreated, it can lead to substance abuse. One of the upsides is it's easier to "forget" that you're addicted to something. I once forget to drink caffeine for a few weeks. Just slipped my mind. I still had the withdrawal symptoms. Headaches, low energy etc., but my brain would not connect the withdrawal to the substance, because from my perspective caffeine did not exist. It was a weird experience.