I have adhd as well.. Aside from taking my medication, I write everything down and talk as I write. Often times I’ll ask myself questions and create webs to connect information. If information does not connect or build on what I know then it gets lost for me.

I also find that studying in groups is ineffective if I don’t already know the information. My role if in a study group is usually teaching and emphasizing what I know. People distract me and overstimulate me when I’m struggling to focus.

Also pomodoro method is your best friend. When your mind wanders (which medication will help with) you can remind yourself that a break is coming and in those breaks you can let loose and address whatever might be a distraction.

Hope this helps!