The brain dysfunctioning could be from the adrenal glands as they are the control centers of the body and do have an impact on neurological functioning...
However, there is an even greater chance that your Omega-3 intake is either low or coming from an inadequate source. Omega-3 essential fatty acids from a good, quality, clean source are proven to increase cognitive functioning and open up the pathways to the brain. They are almost non existant in today's diets.
I devote an entire section to the Power of Omega-3 essential fatty acids in my recently released e-book: "A Dynamic Approach to Healing Adrenal Fatigue."