Thyroid Supplementation for Depression
What is the theory behind using thyroid hormone supplementation in both unipolar & bipolar depression?
Those with depression tend to have a lower production of adenosine triphosphate (ATP) and ATP is required to transport thyroid hormone into the cell where it can exert its actions. So even if you have a normal amount of thyroid hormone in the blood, those with depression may have hypothyroidism.
For those with bipolar depression, does thyroid supplementation trigger mania?
No it does not appear to worsen mania and there is evidence that it improves mixed states.
What are the main side effects of starting thyroid supplementation?
-Feeling hot
-Higher anxiety
-Higher heart rate (lower your caffeine intake!)
-If there is tachycardia (HR>100 at rest) then we need to lower the dose
Can thyroid supplementation help anxiety?
Yes it can, which seems counterintuitive.
What are the longterm side effects of hyperthyroidism?
When someone's thyroid levels are too high, longterm problems include osteoporosis (lower bone density) and heart arrhythmias. But it should be noted that these issues are not seen in the studies of thyroid hormone supplementation in the treatment of depression.
What if the patient is already taking T4 (levothyroxine) to treat hypothyroidism?
It is still ok to try this approach.
What type of thyroid medication and at what dose it is used to treat depression?
T3, or cytomel, is used because it’s shorter acting and it’s therefore faster to get to a steady state.
Start at 25mcg/day x7 days then 50mcg/day x7 days then get vitals.
Then increase to 75mcg/day x7 days and then 100mg/day x7 days and return for a follow up.
The goal dose is anywhere from 50-150mcg/day.
How long is the T3 continued?
For at least 6 months but many are on it for several years.
What labs should be done prior to starting T3 for depression?
Thyroid studies to rule out the existence of hypothyroidism or hyperthyroidism. If these are present, the patient should see an endocrinologist.
