Yes, thyroid disease can affect mood. Common thyroid disease symptoms that affect mood include anxiety or depression. In general, the more severe the thyroid disease, the more severe the mood changes.

With overactive thyroid, a condition called hyperthyroidism, mood symptoms may include:

• Anxiety.
• Nervousness.
• Irritability.

With underactive thyroid, a condition called hypothyroidism, mood symptoms may include:

• Depression.
• Unusual tiredness.

Although thyroid disease can affect mood, it's unusual for those symptoms be the only evidence of thyroid disease. Thyroid disease is associated with many other symptoms such as:

• Weight gain or loss.
• More sensitivity to hot or cold temperatures.
• Bowel movement changes.
• Changes in menstrual cycles.

Treatment for thyroid disease often includes either medicine that lowers the amount of thyroid hormone that the body makes or medicine that replaces missing thyroid hormone. Treatment often improves symptoms caused by thyroid disease, including those that affect mood.