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Q: Thyroid Abnormality or Bipolar Disorder
My question is regarding throid function tests and the "new
guidelines" set by The American Association of Clinical Endocrinologists. The
new normal range is 0.3 - 3.04 as st by AACE. THe old as you may well know was
0.5 - 5.0. This greatly narrows the range of normality of TSH. My level was
3.3 which falls out of new range and my sisters first abnormal reading was the
same. Hypothyroidism runs in the women in the family on my mom's side. I also
take lithium now for almost a year. I haven't had a regular period in 3 months,
and I am in the weirdest depression ever. I am trying to figure out....is this
thyroid abnormality, or just Bipolar Disorder? Any help would be much
appreciated! Thanks!
Dear Ms. B' --
In Oregon there is a superb endocrinologist, if you ever want a consultation on
this issue (separate from bipolar disorder), at OHSU, named Mary Samuels. She's
really busy so you might wait a while to get in. She just came to Corvallis and
gave us a run-down on TSH values, which was excellent. I'll be posting some of
her slides from this presentation on my website under
Thyroid and
Bipolar and will note that I've done so under
What's New if
you want to watch for that. Should happen in a month or so.
Meanwhile, there's one crucial study you should be
aware of, given your question (besides, as confirmed by several doc's including
Dr. Samuels, there is no risk in taking thyroid hormone replacement as long as
you don't make yourself hyperthyroid in the process -- and are willing to buy
pills, have blood tests to make sure you're stable, etc.). The crucial study is
by
Cole and colleagues. Because this is so important, I'm going to copy in
here the abstract from this article, which you might find rather technical, but
might find of interest. I've emphasized the important points in bold and
italics.
Cole DP, Thase ME, Mallinger AG, Soares JC, Luther JF, Kupfer DJ, Frank
E.
Department of Psychiatry, University of Pittsburgh School of Medicine, USA.
OBJECTIVE: Because treatment of the depressed phase of bipolar disorder is a
clinical challenge and hypothyroidism is known to be associated with
depression, the authors examined the relationship between pretreatment thyroid
values and response to antidepressant treatment. It was hypothesized that
subjects with lower thyroid function, even within the normal range, would have
a poorer response to initial treatment. METHOD: The subjects were 65 patients
in the depressed phase of bipolar I disorder who were enrolled in a larger
ongoing study. A panel of thyroid measures, including thyroid-stimulating
hormone (TSH), thyroxine, triiodothyronine resin uptake, and free thyroxine
index (FTI), were determined before initiation of algorithm-guided treatment.
The effect of each thyroid measurement on time to remission was estimated by
using the Cox proportional hazards model. RESULTS: Both lower values of FTI
and higher values of TSH were significantly associated with longer times to
remission, i.e., slower response to treatment. Outcomes were relatively
poor unless patients had FTI values above the median and TSH values below the
median. Patients with this optimal profile experienced remission 4 months
faster than the remainder of the study group. CONCLUSIONS: This study
provides further evidence that patients with bipolar disorder are particularly
sensitive to variations in thyroid function within the normal range.
Our results suggest that nearly three-quarters of patients with bipolar
disorder have a thyroid profile that may be suboptimal for antidepressant
response. It remains to be seen whether pharmacological enhancement of thyroid
function will facilitate recovery from bipolar depression.
You might show this to your doctor and see what she
thinks. As for your menstrual cycle, is that thyroid or bipolar? I don't know
there. It would be interesting to see what your cycle does if your mood gets
better -- which I hope you find a way to bring about soon.
Dr. Phelps
Published October, 2004
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