Think about all of the things that make you smile. Your family or a nice vacation may do the trick. But, you may have forgotten one important thing…
Studies have found that an adequately functioning thyroid gland supports optimal serotonin synthesis, thus, making us happier.
Depression and Hypothyroidism
Serotonin (5-HT) is an inhibitory neurotransmitter that functions to combat depressive moods and promote happiness. Additionally, depression has been associated with decreased serotonin levels, as well as hypothyroidism. Hypothyroidism is simply decreased activity of the thyroid gland.
To connect these links to find if hypothyroidism influences serotonin levels, studies have tested the influence of experimentally induced hypothyroidism in rats.
Hypothyroidism and Serotonin
When adult animals were induced into hypothyroid states, 5-HT turnover in the brainstem was increased (the amount of time 5-HT was available for use was shorter), and cortical 5-HT concentrations were decreased.
Furthermore, when thyroid hormones were administered to these same mice, results demonstrated increased 5-HT concentrations and through a chain of events, more cortical and hippocampal 5-HT release.
There is also some suggestive evidence that thyroid hormones can up-regulate cortical 5-HT2 receptor sensitivity, leading to more serotonin function.
Balancing Serotonin and Thyroid Function
These increases in serotonin neurotransmission can result in happier and more balanced moods. So the next time you find yourself unable to obtain a smile, it may just be your thyroid telling you that it needs a little boost.
Symptoms of Hypothyroidism
Typical signs that a person might be hypothyroid include:
- cold extremities
- decreased stamina and feelings of fatigue
- low libido
- poor memory
- depressive moods
among several other symptoms. A person with a poorly functioning thyroid may also experience hair loss or dry, brittle hair.
The best way to find out if your thyroid is functioning optimally is to visit your practitioner.
Bauer M, Heinz A, and Whybrow PC. 2002. Thyroid hormones, serotonin and mood: of synergy and significance in the adult brain. Mol Psychiatry. 7(2):140-56.
Rahman, MH and Ali, MY. 2014. The Relationship between Thyroid Hormones and the Brain Serotonin (5-Ht) System and Mood: Of Synergy and Significance in the Adult Brain – A Review. Faridpur Med. Coll. J. 9(2): 98-101.