The Claim

Physiological stress, trauma, and chronic inflammation upregulate type 3 deiodinase (D3) activity, redirecting thyroxine (T4) metabolism toward reverse triiodothyronine (rT3) synthesis and away from active triiodothyronine (T3) production. This enzymatic shift induces functional hypothyroidism characterized by normal circulating T4 and TSH levels but reduced intracellular T3 bioavailability, potentially contributing to mood and cognitive impairments in affected individuals.

Source: The Influence of Reverse Triiodothyronine on Neuropsychiatric Disorders: A Narrative Review.

What the research says

Roughly balanced

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Supports
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Challenges
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How it works
1 study reviewed
In plain English

When your body is under long-term stress, trauma, or constant inflammation, it produces more of an enzyme that converts your main thyroid hormone into an inactive form. This leaves your cells starved of active thyroid hormone even though standard blood tests look normal, which can lead to brain fog, low mood, and cognitive problems.

See the scientific wording

Physiological stress, trauma, and chronic inflammation increase type 3 deiodinase (D3) activity, which shifts thyroxine (T4) metabolism away from active triiodothyronine (T3) production toward reverse triiodothyronine (rT3) synthesis. This metabolic shift creates a state of functional hypothyroidism characterized by normal serum T4 and TSH levels but significantly diminished intracellular T3 action, which may underlie mood and cognitive dysfunction in stressed or inflamed individuals.

What the research says

1 study

  1. Study: The Influence of Reverse Triiodothyronine on Neuropsychiatric Disorders: A Narrative Review.

    Stress and inflammation can change how your body processes thyroid hormones, turning active thyroid hormone into an inactive form that blocks brain function. This hidden shortage of active thyroid hormone in cells can lead to depression and brain fog, even when standard blood tests look normal.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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