Thyroid and Mood
Thyroid hormone levels are linked with well-being among patients on thyroid hormone replacement therapy, a recent study has found.
The thyroid gland, in the lower neck, produces hormones which regulate our metabolism and have direct effects on most organs. All cells in the human body will respond to changes in thyroid hormones with a change in the rate at which they work.
A lack of thyroid hormone, hypothyroidism, has long been linked to cognitive and memory problems and mood disorders, possibly through the brain chemical serotonin. But could normal hormone levels also be linked to well-being?
So far, the evidence for smaller variations in thyroid hormone levels affecting mood and psychological wellbeing remains controversial. Some studies have suggested a link with depression, mental impairment and memory loss, but others have failed to find such a link. However, in studies where thyroid hormone levels are raised using hormone therapy, psychological well-being tends to improve.
A team of researchers from the Henry Wellcome Lab for Integrative Neuroscience and Endocrinology at Bristol University, UK set out to investigate changes in thyroid hormone levels within the “normal” range.
Dr. Colin Dayan and his team recruited 697 men and women with hypothyroidism about to take part in a study on the treatment. All were 18 to 75 years old (mean 57 years) and were taking at least 100ug of thyroxine as thyroid hormone replacement therapy. Most patients (68 percent) currently had thyroid hormone levels within the normal range.
Measurements were taken of their levels of the hormone free thyroxine (fT4), and well-being was assessed using the reliable and widely-used General Hospital Questionnaire. The participants also filled in the Hospital Anxiety and Depression Scale and the Thyroid Symptom Questionnaire.
Overall, those with higher levels of fT4 had significantly better well-being. This link could not be explained by age or gender. A significant link also was found between lower well-being and higher levels of TSH, thyroid-stimulating hormone. This was expected, as higher TSH can indicate thyroid problems.