Are thyroid deficiency and depression related?

Thyroid deficiency alone can cause some depressive symptoms. Together with unipolar major depression, thyroid deficiency can make depressive symptoms worse and make major depression harder to treat. If you feel slowed down or exhibit symptoms of depression, you should ask your doctor for a thyroid test if you have not had one within six months. Three laboratory tests for thyroid function many psychiatrists use are TSH, serum Free-T4 and serum Free-T3.