Using PET imaging, researchers have found a definitive connection between hypothyroidism is often and mood changes such as depression lethargy. The study was detailed at SNM 2007 this week in Washington, D.C.
"The aim of our study was to investigate—with positron emission tomography (PET) imaging—how physical health and mental health are interrelated," said Waltraud Eichhorn, a nuclear medicine physician at Johannes Gutenberg University in Mainz, Germany. "We found that hypothyroidism is correlated to regional metabolic changes in the thalamus—an area of the brain that helps process information from the senses and transmit it to other parts of the brain.”
"In other words, hypothyroid patients—compared to healthy individuals—have decreased metabolism in special parts of the brain that are responsible for processing information," said Eichhorn. "Remarkably, this reduction in metabolism remains detectable after thyroid hormone replacement therapy," she added.
The thyroid, a butterfly-shaped gland in the neck just above the collarbone, is an endocrine gland that makes hormones and helps set a body's metabolism. If the gland produces too little of its hormone, the result can be lethargy in patients.
In this study, 10 patients with hypothyroidism underwent a cerebral 18-FDG/PET examination. Eichhorn said that that further research is needed to determine whether special brain regions are responsible for increased depression or anxiety in patients suffering from hypothyroidism.