Kristen M Geroge et al. studied 12,481 participants and found a higher risk of dementia (hazard ratio [HR] [95% CI]: 1.40 [1.02 - 1.92]) among the overt hyperthyroid patients than the euthyroid participants. The dementia risk is increased by abnormal thyroid hormone levels (high or low) and autoimmunity from autoimmune thyroid disease (AITD) [17]. This evidence concerns the gene TG and dementia.