Levothyroxine "augmentation" for depression.
Article Type: Brief article
Subject: Depression, Mental (Drug therapy)
Author: Gaby, Alan R.
Pub Date: 06/01/2008
Publication: Name: Townsend Letter Publisher: The Townsend Letter Group Audience: General; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2008 The Townsend Letter Group ISSN: 1940-5464
Issue: Date: June, 2008 Source Issue: 299
Geographic: Geographic Scope: United States Geographic Code: 1USA United States
Accession Number: 217848129
Full Text: Seventeen euthyroid women (aged 30-60 years) with depression that had failed to respond to serotonergic antidepressants (tricyclic or selective serotonin-reuptake inhibitors) received 100 mcg/day of levothyroxine for four weeks while continuing their previous medication. After four weeks, 11 women (65%) were in remission, defined as a score of 7 or less on the Hamilton Depression Rating Scale (HDRS). Five other patients showed a decrease of more than 50% on the HDRS. Thus, 94% of the patients showed improvement or resolution of symptoms. The efficacy of levothyroxine augmentation did not correlate with pretreatment laboratory tests results for thyroid function (T3, T4, TSH, and TRH stimulation test), all of which were normal.

Comment: Previous studies have shown that the addition of triiodothyronine (T3) to standard therapy is often effective for depressed patients who have failed to respond to antidepressant drugs alone. The present study suggests that a moderate dose of levothyroxine (T4) is also effective when used as adjunctive therapy. In most of these studies, the investigators assumed that thyroid hormone somehow caused the antidepressants to work better. An alternative explanation is that some of the successfully treated patients were clinically hypothyroid and that they would have improved with thyroid hormone alone, without the use of antidepressants. Although the patients in the present study were euthyroid according to standard laboratory tests, it is my belief that these tests fail to identify a large proportion of patients who are clinically hypothyroid (see Gaby AR. "Sub-laboratory" hypothyroidism and the empirical use of Armour thyroid. Altern Med Rev. 2004;9:157-179.)

Lojko D, Rybakowski JK. L-thyroxine augmentation of serotonergic antidepressants in female patients with refractory depression. J Affect Disord. 2007; 103:253-256.

by Alan R. Gaby, MD

drgaby@earthlink.net
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