Hypothyroidism in patients with bipolar I disorder treated primarily with lithium.
OBJECTIVE
This study evaluated the frequency and clinical significance of abnormal Thyroid Stimulating Hormone (TSH) and Free Thyroxine Index (FTI) in patients with bipolar I disorder treated primarily with lithium.


METHODS
We evaluated the medical records of 143 participants in the Pittsburgh study of Maintenance Therapies in Bipolar Disorder who did not have a thyroid abnormality at entry.


RESULTS
Thirty-six percent of the 143 patients developed abnormal TSH and/or FTI values. Thirty-eight percent of the 135 patients who received lithium developed abnormal TSH and/or FTI, spent significantly longer time in the acute treatment phase (t = -3.6, df = 133, p = .0004), and had significantly higher mean Hamilton Scale for Depression scores over the course of the maintenance phase (t = -2.3, df = 71.6, p = .03). Time on lithium and development of abnormal TSH and/or FTI were positively correlated (r = .25, p = .004).


CONCLUSIONS
Thyroid dysfunction can be frequent in patients exposed to lithium treatment for bipolar I disorder; it also appears to be correlated with a slower response to acute treatment, and may be related to poorer quality of long-term remission. A prospective study is needed to confirm our findings and determine whether more aggressive thyroid replacement can optimize thyroid function to facilitate clinical recovery.


BACKGROUND
Supported in part by National Institute of Mental Health Grants MH 029618 (Drs. Frank and Fagiolini) and MH 030915 (Drs. Kupfer and Fagiolini), and the Bosin Memorial Fund of The Pittsburgh Foundation (Drs. Fagiolini, Kupfer, Cook, Scott, Novick and Frank). Dr. Fagiolini is on the advisory board and a consultant to Pfizer Inc, and Bristol Myers Squibb, and is on the speaker bureau of Bristol Myers Squibb, Eli Lilly Italy, Pfizer Inc, and Shire. Dr. Frank is on the advisory board of Pfizer Inc. and Eli Lilly & Company, and is a consultant to Pfizer Italia and Servier Amerique. Dr. Kupfer is on the advisory board of Pfizer, Inc., Forest Pharmaceuticals, Inc., and Solvay-Wyeth Pharmaceuticals, and is a consultant to Servier Amerique.
Fagiolini
Andrea
A
Department of Psychiatry, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania 15213, USA. fagiolinia@msx.upmc.edu
Kupfer
David J
DJ
Scott
John
J
Swartz
Holly A
HA
Cook
David
D
Novick
Danielle M
DM
Frank
Ellen
E
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced* / Q000503:physiopathology; D016651:Lithium Carbonate / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism
D014150:Antipsychotic Agents; D016651:Lithium Carbonate; D013972:Thyrotropin; D013974:Thyroxine