New research suggests that when older adults have a thyroid that is more active than normal it can increase their risk of depression.
The thyroid gland regulates the body's metabolism, but it has also been known to have an effect of mental health, an Endocrine Society news release reported.
Overactive and under-active thyroids have been linked to depression risk in the past; this is he first study that found a link between thyroid activity and depression within the normal range.
Researchers looked at levels of the thyroid-stimulating hormone (TSH), which signals the gland to release more hormones, to determine thyroid activity.
"We found that older individuals with thyroid activity at the high end of the normal range had a substantially increased risk of developing depression over the course of an eight-year period compared to individuals who had less thyroid activity within the normal range," study authors, Marco Medici, MD, of the Erasmus Medical Center in Rotterdam, the Netherlands said in the news release. "This suggests that people with even minor changes in thyroid function may experience similar mental health effects as those with overt thyroid disorders, including hypothyroidism and hyperthyroidism."
The research team looked at a cohort study consisting of 1,503 with an average age of 70. The team looked at the patients' TSH levels and compared the results with their depression symptoms, this information was obtained through questionnaires. These patients showed no depression symptoms during the first visit but some developed them over the course of the eight year study.
The participants were divided into three groups based on their TSH levels; the team found the subjects within the most active thyroid range were most likely to develop depressive symptoms.
"These results provide insight into the powerful effects thyroid activity can have on emotions and mental health," Medici said. "This information could influence the process of diagnosing and treating depression, as well as treatments for individuals with thyroid conditions."
