Link between Thyroid function and depression. SSRI's enhance activity of D2 result in increased conversion of T4 into active T3 in brain.

[cc120]

It has been hypothesized that depression leads to inhibition of the D2 enzyme responsible for conversion of T4 into T3 due to the increase...

Both tricyclic antidepressants [77] and SSRIs [78] appear to enhance the activity of D2 resulting in an increased conversion of T4 into active T3 in the brain. T3 was suggested to enhance neurotransmission in the central noradrenergic pathways [79] and deficiency in catecholamines has been raised as a possible mechanism in depression [80]. Additionally, it has been shown that anti-depressants with variable mechanisms of action have different effects on thyroid indices [81]. Further studies are therefore required to better elucidate this complex interaction between the HPT axis and the neurotransmitter system.

ncbi.nlm.nih.gov/pmc/articl...

[Clutter]

Cc120,

Seems to disprove that "SSRIs negate thyroid hormone" which a member used to post.

[thyr01d]

How very interesting, thank-you for posting this. Most interesting because it would explain why so many GPs put patients with underactive thyroid symptoms onto antidepressants - they do help the feedback the GP receives suggests the patient was depressed. Of course we all want to argue the other way, that it's not antidepressants we need but correcting of the thyroid problem.

[cc120 in reply to thyr01d]

Absolutely.

[lucylocks]

I belong to another forum and there a few members who keep telling me to get off the anti depressants as they are bad for the thyroid. They are really against them, but I do feel they do have a place and do help a lot of people.

From my results from a 24 hour urine test and my blood results on NDT they told me I must be a very good converter of T4 to T3. I wonder now is this because I take A.D's.

[cc120 in reply to lucylocks]

Yes, confusing isn't it.