Low dopamine is also related to ADD. I have mild ADD and mild catecholamine depression. (After 1.75 yrs of chelation my doctor just finished weaning me off of the ADD meds I had been on for the past 5 yrs. I'm still on supplements.) I can't say that the medicine--Adderall--or supplements had much impact on my brain fog.
Some say magnesium helps. I can't say it was the magic bullet for me.