Low Mood and Depression
Thyroid disease can affect mood profoundly. Hypothyroidism commonly causes low mood, apathy and a sense of slowing down, while hyperthyroidism tends to cause anxiety, irritability and restlessness.
Because mood symptoms are so common, thyroid function is worth checking when they appear alongside physical symptoms.
Last medically reviewed: 15 November 2025
The thyroid–mood link
Thyroid hormone influences brain chemistry and energy regulation. When levels are low, people can feel depressed, mentally slowed and unmotivated; when levels are high, they can feel anxious and on edge.
These effects overlap closely with primary mood disorders, which is why they can be missed.
Clues that point to the thyroid
Mood changes accompanied by weight change, temperature intolerance, fatigue, constipation, palpitations or hair thinning raise the possibility of thyroid disease.
A simple TSH test can clarify the picture.
Treatment
Correcting thyroid dysfunction often improves mood, though it can take weeks to months and may not fully resolve symptoms. If low mood persists despite normal thyroid levels, it should be assessed and treated in its own right.
Mood symptoms should never be dismissed as “just the thyroid” — both may need attention.
Frequently asked questions
Can thyroid disease cause depression?
Yes — hypothyroidism commonly causes low mood and mental slowing, which often improves with treatment, though it may take time.
Can an overactive thyroid cause anxiety?
Yes — hyperthyroidism frequently causes anxiety, irritability and restlessness, which usually ease as thyroid function is controlled.
Should I be tested for thyroid problems if I feel depressed?
If you also have physical symptoms such as weight or temperature changes, fatigue or palpitations, thyroid testing is reasonable. Discuss it with your clinician.
References & further reading
This page is based on established medical knowledge and guidelines from authoritative sources. Always consult a qualified clinician for personal medical advice.
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