Can thyroid issues affect cognitive health?

Low serum thyroid-stimulating hormone (TSH), a symptom of thyroid toxicosis, can result from thyroid problems or overmedication for hypothyroidism. Research suggests it might heighten the risk of dementia.

A study published in the Journal of the American Medical Association (JAMA) tracked 66,000 individuals without prior low TSH or cognitive problems. Between 2014 and 2023, 2,700 participants had low TSH (60% due to medication). Also, 4,800 were diagnosed with cognitive disorders. At age 75, 11% with thyrotoxicosis and 6% without it developed cognitive issues; at age 85, the numbers rose to 34% and 26%, respectively.

Adjusting for various factors, any thyrotoxicosis was linked to a 39% higher risk of cognitive disorders. Specifically, severe exogenous thyrotoxicosis (TSH (0.1 mIU/L) showed the strongest association with increased risk for cognitive problems.

In essence, low TSH levels due to thyroid troubles or overmedication might raise the risk of cognitive issues, including dementia. Understanding this link can help in the earlier identification and management of these conditions.