The functional behavior of the thyroid is fundamental in most diseases and represents the basis for diagnosis and therapy. The status can be euthyroidism, hypothyroidism or hyperthyroidism. The psychiatric manifestation varies in different thyroid status. Those with hypothyroidism were described to have depression, psychosis and cognitive dysfunction. Meanwhile, those with hyperthyroidism were found to have psychosis, aggression, anxiety as well as cognitive impairment.