Thyroid function in clinical subtypes of major depression: an exploratory study

Abstract

<p/> <p>Background</p> <p>Unipolar depression might be characterized by a 'low-thyroid function syndrome'. To our knowledge, this is the first study which explores the possible relationship of DSM-IV depressive subtypes and the medium term outcome, with thyroid function.</p> <p>Methods</p> <p>Material: Thirty major depressive patients (DSM-IV) aged 21–60 years and 60 control subjects were included. Clinical Diagnosis: The SCAN v 2.0 and the IPDE were used. The psychometric Assessment included HDRS the HAS and the GAF scales. Free-T3, Free-T4, TSH, Thyroid Binding Inhibitory Immunoglobulins (TBII), Thyroglobulin antibodies (TA) and Thyroid Microsomal Antibodies (TMA) were measured in the serum. The Statistical analysis included 1 and 2-way MANCOVA, discriminant function analysis and Pearson Product Moment Correlation Coefficient.</p> <p>Results</p> <p>All depressive subtypes had significantly higher TBII levels in comparison to controls. Atypical patients had significantly higher TMA in comparison to controls. No significant correlation was observed between the HDRS, HAS and GAF scales and thyroid indices. Discriminant function analysis produced functions based on thyroid indices, which could moderately discriminate between diagnostic groups, but could predict good response to treatment with 89.47% chance of success.</p> <p>Conclusion</p> <p>Although overt thyroid dysfunction is not common in depression, there is evidence suggesting the presence of an autoimmune process affecting the thyroid gland in depressive patients</p

Thyrotropin, but not a polymorphism in type II deiodinase, predicts response to paroxetine in major depression

“…Some indication of the importance of TPO antibodies was given by a study wherein the presence of TPO-antibodies in the first trimester of pregnancy, but not subclinical hypothyroidism per se, predicted postpartum depression (33). A recent study described that the presence of Thyroid Binding Inhibitory Immunoglobulins was related to treatment non-response in depressed patients (34). These findings support an association between the immune system and depression.…”

Brain-immune interactions and disease susceptibility

“…134 Taken together, studies of the HPT in MDD show evidence of altered activity of the HPT axis in some cases of depression, including (1) increased total and/or free T4, without T3 alterations; 128 (2) reduction in serum T4 concentration during a wide range of somatic treatments; 128,135 (3) increased TSH in 2-2.6% of patients; 125,129 (4) excessive response of TSH to the TRH challenge test in 10% and a blunted response in 25% of the patients; [135][136][137] and (5) high levels of antithyroid antibodies. 124,128,138,139 Some speculate that the mechanism of T4 increase with blunted TSH response to TRH reflects glucocorticoid activation of hypothalamic neurons. Bruhn et al 140 found that exposure of hypothalamic cultured fetal rats to glucocorticoids increased the genetic expression of TRH.…”

A Complex Equation: Low Mood, Fatigue, and Hyperphagia

“…6 On the contrary, other studies have suggested that the presence of subtle thyroid function abnormalities does not have an impact on treatment outcome. 4,7 In our patient, some improvement in her symptoms was noted when she was on both fluoxetine and levothyroxine.…”

“…Although the link with depression 4 It is important to highlight the association of thyroid autoimmunity with treatment outcome. It has been suggested that the presence of antithyroid antibodies predicts a poor response to standard antidepressant treatment.…”