I have diagnosed ADHD and I do not have social media (besides HN), distracting apps or anything. I just have stock GrapheneOS on my phone, no extra distractions.
This helps tremendously but doesn't really affect the core issues of adhd, which are a lack of focus when that is needed. Note that it's not a general lack of focus and not a lack of discipline. People with ADHD often fall into depression because they cannot focus well enough even with the right discipline and motivation.