Is autoimmune thyroiditis part of the genetic vulnerability (or an endophenotype) for bipolar disorder?
ABSTRACT Both genetic and environmental factors are involved in the etiology of bipolar disorder; however, biological markers for the transmission of the bipolar genotype ("endophenotypes") have not been found. Autoimmune thyroiditis with raised levels of thyroperoxidase antibodies (TPO-Abs) is related to bipolar disorder and may be such an endophenotype. This study was intended to examine whether autoimmune thyroiditis is related to the disease itself, to the (genetic) vulnerability to develop bipolar disorder, or both.
Blood was collected from 22 monozygotic (MZ) and 29 dizygotic (DZ) bipolar twins and 35 healthy matched control twins to determine TPO-Abs.
The TPO-Abs were positive in 27% of the bipolar index twins, 29% of the monozygotic bipolar cotwins, 27% of the monozygotic nonbipolar cotwins, 25% of the dizygotic bipolar cotwins, 17% of the dizygotic nonbipolar cotwins, and in 16% of the control twins. Repeated measures analysis of covariance on log-transformed absolute TPO-Abs values revealed significantly increased mean TPO-Abs levels in discordant twin pairs as compared with healthy twin pairs, whereas no difference was found between bipolar patients and their (discordant) nonbipolar cotwins.
This study shows that autoimmune thyroiditis is related not only to bipolar disorder itself but also to the genetic vulnerability to develop the disorder. Autoimmune thyroiditis, with TPO-Abs as marker, is a possible endophenotype for bipolar disorder.
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ABSTRACT: In a nationwide prospective cohort study, we examined the possible association between maternal autoimmune disease (AD) and later diagnosis of Tourette syndrome (TS) in offspring. Data from national Danish health registers identified a cohort consisting of all children born in Denmark between 1990 and 2007 (n = 1,116,255), followed prospectively from birth until 2011, date of TS diagnosis, death, or emigration/disappearance, whichever came first. The incidence rate ratio (IRR) of TS, dependent on whether or not the mother had a prior diagnosis of AD, was estimated by Poisson regression with 95% CIs and adjusted for age, calendar time, place of birth, maternal and paternal age, parental psychiatric diagnoses other than TS, and parental TS. The cohort contributed a total of 13,000,162 person years and 2,442 participants with a diagnosis of TS (414 females and 2,028 males). Prior maternal AD was found in 110 of the 2,442 children with TS, corresponding to an increased risk of TS, with an adjusted IRR of 1.22 (95% CI = 1.01-1.48). Maternal history of a prior AD increased the risk of TS in males, with an adjusted IRR of 1.29 (95% CI = 1.05-1.58), but not in females, with an adjusted IRR of 0.89 (95% CI = 0.52-1.52). Maternal AD was associated with a 29% increased incidence rate of TS in male offspring. This finding supports the hypothesis that neuroimmunological disorders may act as a component in the etiology of a subset of TS. Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.Journal of the American Academy of Child & Adolescent Psychiatry 03/2015; 54(6). DOI:10.1016/j.jaac.2015.03.008 · 6.35 Impact Factor
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ABSTRACT: Thyroid diseases are often associated with psychiatric disorders. The prevalence of autoimmune thyroiditis in the general population is estimated to be at about 5-14 %. A clinical study was conducted to evaluate the association between autoimmune thyroiditis and depression in psychiatric outpatients. Fifty-two patients with depression and nineteen patients with schizophrenia (serving as control group), attending a psychiatric outpatient unit, were included. In addition to the measurement of thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, antithyroid peroxidase (anti-TPO) antibodies, and anti-thyroglobulin antibodies, ultrasound examination of the thyroid gland was performed. The proportion of pathologically increased anti-TPO levels in patients with depression was high. Furthermore, the distribution of pathologically increased anti-TPO levels was significantly (χ (2) = 5.5; p = 0.019) different between patients with depression (32.7 %) and patients with schizophrenia (5.3 %). In a gender- and age-adjusted logistic regression, the odds ratio of uni- or bipolar patients with depression for an autoimmune thyroiditis was ten times higher (95 % CI = 1.2-85.3) when compared with schizophrenia patients. TSH basal level did not differ between patients with depression and patients with schizophrenia. Our study demonstrates a strong association between anti-TPO levels, which are considered to be of diagnostic value for autoimmune thyroiditis (in combination with a hypoechoic thyroid in ultrasonography) with uni- or bipolar depression. It should be noted that the routinely measured TSH level is not sufficient in itself to diagnose this relevant autoimmune comorbidity.European Archives of Psychiatry and Clinical Neuroscience 09/2014; 265(1). DOI:10.1007/s00406-014-0529-1 · 3.36 Impact Factor
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ABSTRACT: Background & objectives: Abnormalities in thyroid hormonal status is common in major psychiatric disorders. Although the relevance of thyroid dysfunction to bipolar disorder is well-recognized, yet the association between thyroid dysfunction and schizophrenia-spectrum disorders is under-emphasized. The aim of this study was to examine and compare the rates of abnormal thyroid hormonal status in patients with schizophrenia-spectrum disorders and mood disorders in an inpatient tertiary care general hospital psychiatry unit. Methods: This was a retrospective hospital-based study on 468 inpatient samples. Data on serum thyroid stimulating hormone (TSH), T3 (triiodothyroxine), T4 (L-thyroxine), free unbound fractions of T3 and T4 (FT3 and FT4) were obtained from records of 343 patients, 18 patients were anti-TPO (anti thyroid peroxidase antibody) positive. The rates of abnormal thyroid hormonal status were compared using the chi square test. Results: Abnormal thyroid hormonal status in general, and presence of hypothyroidism and hyperthyroidism, in particular were seen in 29.3, 25.17 and 4.08 per cent patients with schizophrenia spectrum disorders, respectively. These were comparable to the rates in patients with mood disorders (23.24, 21.62 and 1.62%, respectively). Eleven of the 18 patients with antiTPO positivity had a schizophrenia-spectrum disorder. There were no gender differences. Interpretation & conclusions: Thyroid dysfunction was present in patients with schizophrenia-spectrum disorder as well as mood disorders. Autoimmune thyroid disease was more commonly seen in patients with schizophrenia-spectrum disorders compared to mood disorders. The findings reiterate the relevance of screening patients with schizophrenia-spectrum disorders for abnormal thyroid hormonal status.The Indian Journal of Medical Research 12/2013; 138(6):888-93. · 1.66 Impact Factor