I agree with lindsey. The answer is probably individual. A thyroid which is not functioning well sets up issues in many of our internal systems which can include cortisol. Please when you have time and the energy take a look at the US thyroid support site. (there are others, Canada, UK and Australia, probably more) The site will help you understand thyroid function. You should be able to relate information to your own symptoms, there may be things you can do which may help. Brain fog and memory problems are a real pain. There are many of us who would love to have body systems which behave as they should and are working towards this, some have better help from their physicians, I hope you are one. The more you know the better able you are to be active in your health and work towards recovery rather than passive.

All the best.