Triiodothyronine Augmentation of Selective Serotonin Reuptake Inhibitors in Posttraumatic Stress Disorder

Background: There is considerable comorbidity ofmajor depression and posttraumatic stress disorder (PTSD), andantidepressants have been reported to be effective in treatingPTSD. Addition of triiodothyronine (T₃) to ongoingantidepressant treatment is considered an effective augmentationstrategy in refractory depression. We report the effect of T₃augmentation of antidepressants in patients with PTSD.

Method: T₃ (25 microg/day) was addedto treatment with a selective serotonin reuptake inhibitor (SSRI)(paroxetine or fluoxetine, 20 mg/day for at least 4 weeks and 40mg/day for a further 4 weeks) of 5 patients who fulfilled DSM-IVcriteria for PTSD but not for major depressive disorder (althoughall patients had significant depressive symptoms). TheClinician-Administered PTSD Scale, the 21-item Hamilton RatingScale for Depression, and the Clinical GlobalImpressions-Severity of Illness scale were administered every 2weeks, and self-assessments were performed with a 100 mm visualanalog mood scale.

Results: In 4 of the 5 patients, partialclinical improvement was observed with SSRI treatment at a dailydose of 20 mg with little further improvement when the dose wasraised to 40 mg/day. This improvement was substantially enhancedby the addition of T₃. Improvement was most strikingon the Hamilton Rating Scale for Depression.

Conclusion: T₃ augmentation of SSRItreatment may be of therapeutic benefit in patients with PTSD,particularly those with depressive symptoms. Larger samples andcontrolled studies are needed in order to confirm thisobservation.