Christine,
Thyroid dysfunction has been associated with anxiety and depression but primary endogenous(ie no stressor/biologic in orgin) is probable more common. This issue has been discussed previously in this forum. I recommend that you discuss this issue further with your mothers physician. Generally thyroid problems are not episodic like depression and anxiety can be. Good luck. Hope this was helpful.
Sincerely,
HFHS MD-JM
Keywords: Thyroid dysfunction, anxiety, depression