I have read that hyperthyroidism can cause depression. Is this because of low serotonin levels or is there is another cause? Does this kind of depression need to be checked by a psychiatrist?

Edit (if it is too broad I can remove this edit): Can depression lead to thyroid hormone fluctuation?

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    Depression, isn't necessarily caused by Serotonin reuptake. Presently, much research is being done towards depression on a Neurological level. A "Biochemical imbalance", is an outdated theory.
    – user19679
    Jan 22, 2016 at 3:39
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    @user19679 If you have something you'd like to contribute, we encourage you to post it as an answer and provide a source please! :)
    – Dave Liu
    Jan 27, 2016 at 7:02

1 Answer 1


Thyroid function and serotonin activity are highly linked. Serotonin stimulates hypothalamic TRH (Thyroid Releasing Hormone) production, leading to an increase in TSH (Thyroid Stimulating Hormone) production from the pituitary.

Serotonin stimulates hypothalamic TRH production which leads to an increase in TSH production from the pituitary. Adequate serotonin production is necessary to maintain thyroid hormone levels. Theoretically, an excess of serotonin may lead to the opposite reaction. For example, excess serotonin can lead to a reduction in dopamine production, which can then lead to an increase in norepinephrine production, leading to an increased stress response and cortisol production.

When your serotonin levels are low, you feel anxious, depressed, and pessimistic, and you might also struggle with sleep problems — all common symptoms associated with hyperthyroidism.

Sources: https://www.ncbi.nlm.nih.gov/pubmed/11840307 https://www.ncbi.nlm.nih.gov/pubmed/18208678

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    Welcome to Health.SE! This looks like it might be a on its way to a good answer. However, please take a look at this meta post Quality of References and try to edit your answer accordingly. Oct 18, 2017 at 9:44
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    +1 thanks for including sources. Because markdown here is a bit modified: Using ">" you can format something as a quote from an external source. Maybe, if you can spare the time, you could edit in quotes from your source.
    – Narusan
    Oct 18, 2017 at 16:21
  • Excessive serotonin can cause serotonin syndrome, for those who want to research more on it. Jan 26, 2018 at 16:50

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