I have seen a patient once who presented with depression and some anxiety symptoms. On further questioning, she had other symptoms of weight gain, thinning of hair, cold intolerance and constipation. She had a family history of both depression, anxiety and thyroid disease. As part of her organic or physical screen, we did blood tests. This confirmed that she had hypothyroidism (low thyroid).
In conclusion, her hypothyroidism has probably triggered her depression and explained her other symptoms of weight gain, thinning of hair, cold intolerance, constipation, and flat mood.
This highlights the importance of doing a physical screen for anyone who presents with symptoms of depression, anxiety or any mental health disorders.
Talk to your Doctor about all of your symptoms even if you think they are irrelevant.