Thanks for your query
The thyroid profile of your husband is totally normal. Its not a feature of thyroiditis
. This depression may come from his increasing age and presence of many co-morbidities like diabetes, hypertension
. So consult a doctor and get him examined physically. Also check recent value of his fasting and post-prandial blood sugar, blood pressure and lipid profile
. Diabetes may cause weight loss if uncontrolled. Ask your doctor to investigate your husband to look for causes of this weight loss. But as per as thyroid function is considered there is no abnormality.