Thyroid disorders are known to induce neuropsychiatric manifestations and different neuropsychiatric manifestations are dementia, mania, depression, and autoimmune hashimoto encephalopathy. Hypothyroidism is associated with depression and mania, and hyperthyroidism is linked with dementia and mania. Cognitive impairment can result from thyroid disease. Subclinical hyperthyroidism, thyroid-stimulating hormone levels below the normal range, and high levels of free thyroxine raise the risk of dementia in the elderly.
Thyroid diseases can present with different neuropsychiatric manifestations with or without any clinical signs along the temporal course of the disease. So, while dealing with neuropsychiatric or neurocognitive manifestations, thyroid disease should be ruled out by appropriate thyroid function tests which include free T3, free T4, TSH, and thyroid antibody tests.
