Abnormal Thyroid Function Tests in Psychiatric Patients: A Red Herring?

Abstract

Thyroid abnormalities can induce mood, anxiety, psychotic, and cognitive disorders. Thus, thyroid function tests are routinely checked in psychiatric patients. However, up to one-third of psychiatric patients may demonstrate thyroid function test abnormalities that do not reflect true thyroid disease, but rather are a manifestation of secondary effects on one or more levels of the hypothalamic-pituitary-thyroid (HPT) axis. Originally termed the euthyroid sick syndrome, this phenomenon is now more commonly referred to as "non-thyroidal illness." In psychiatric patients with non-thyroidal illness, patterns of thyroid function test abnormalities may vary considerably based upon factors such as the underlying psychiatric disorder, the presence of substance abuse, or even the use of certain psychiatric medications. Thus, any abnormal thyroid function tests in psychiatric patients should be viewed with skepticism. Given the fact that thyroid function test abnormalities seen in non-thyroidal illness usually resolve spontaneously, treatment is generally unnecessary, and may even be potentially harmful.

Prolactin levels in drug-naïve patients with schizophrenia and other psychotic disorders

“…TSH and thyroid hormone (FT4) levels did not differ significantly between the two groups, thus eliminating the hypothesis that hyperprolactinaemia was due to hypothyroidism. Total T3 levels were lower in the patient group, which is consistent with previous findings and may reflect reduced peripheral conversion of T4 to T3 (Spratt et al 1982;Dickerman & Barnil 2012).…”

Thyroid Profile in Drug Naive Cases of Depression

“…[1][2][3][4] show that that the female subjects comprised a greater proportion of the sample size compared to male subjects in both the study and control group. The maximum number of married people (70%) has depression compared to unmarried people (28%).…”

“…Even though depression is predominantly expressed through psychological symptoms, it is considered as a biological disorder and many times often it responds well to biological treatments [4].…”

Study of Thyroid Abnormalities in Psychiatric Out Patients with Depression At A Tertiatry Care Centre in Central India

“…The prevalence of euthyroid sick syndrome ranges from 7 to 33 per cent in psychiatric inpatients 1,13 while euthyroid hyperthyroxinemia is thought to be more common in mood disorders 14 . Although it is difficult to distinguish nonthyroidal illness from true thyroid dysfunction in euthyroid subjects, the TSH level in euthyroid sick syndrome is upto 15-20μIU/ml 15 .…”

“…Originally termed the euthyroid sick syndrome, this phenomenon is now more commonly referred to as "non-thyroidal illness." 1 Nonthyroidal illness is characterized by the presence of altered thyroid function parameters www.jmscr.igmpublication.org Impact Factor 3.79 ISSN (e)-2347-176x DOI: http://dx.doi.org/10.18535/jmscr/v3i10.03 that are not considered indicative of actual thyroid disease but rather occur as a response to underlying systemic or acute psychiatric illness. This syndrome may be seen in a variety of systemic illnesses and stress states, as well as in psychiatric illness.…”