I think it's important not to understate the importance of placebo in the effects, but psychedelics can lead you to confront the problems in your life in a way that you simply can't otherwise. These confrontations can be so profound and emotional that they leave a permanent impact on you. If you wrestle with the problems in your life, identify them as caused by ADHD symptoms, and commit to solve them while on LSD, you'll end up being very motivated to solve them.

This experience can be as impactful as when people "find god" while struggling through something and then finally find the willpower to overcome it. Actually it can be more impactful; consider that a psychedelic user perceives that they are meeting with God and God is directly telling them what they need to change and how they need to do it, while the born-again Christian has only thoroughly convinced himself that his own will is actually God's will instilled within him, via faith. The psychedelic experience is much more powerful and much less fragile than the religious experiences that we are used to hearing about helping people through hardships.

And ADHD is a condition whose effects can be entirely overcome through willpower.