Rapid cycling bipolar disorder is associated with antithyroid antibodies, instead of thyroid dysfunction

Zhaoyu Gan,Yingtao Liao,Qi Zhang,Zhihua Yang,Xiuhua Wu,Zimeng He,Yingdong Wu,Zhongcheng Chen

doi:10.1186/s12888-019-2354-6

Abstract

BackgroundConclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting. Previous studies suggest that the impact of antithyroid antibodies on mental wellbeing seems to be independent of thyroid function. Here, we investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD).MethodsFast serum levels of free thyroxine (FT4), free triiodothyronine (FT3), thyroid Stimulating Hormone (TSH), TPO-abs and Tg-abs were simultaneously measured in 352 patients with BD. Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education.ResultsNeither hypothyroidism nor hyperthyroidism was significantly associated with RCBD. Both TPO-abs and Tg-abs were significantly related to RCBD, even after controlling for gender, age, marriage status, education, antidepressants treatment, comorbidity of thyroid diseases, and thyroid function (serum levels of FT3, FT4 and TSH). Although TPO-abs and Tg-abs were highly correlated with each other, binary logistic regression with forward LR selected TPO-abs, instead of Tg-abs, to be associated with RCBD. TPO-abs was significantly, independently of Tg-abs, associated with hyperthyroidism, while Tg-abs was marginally significantly related to hypothyroidism at the presence of TPO-abs.ConclusionTPO-abs might be treated as a biomarker of RCBD. Further exploring the underlying mechanism might help understand the nature of RCBD and find out new treatment target for it.

Highlights

Conclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting
Except Young Mania Rating Scale (YMRS) total scores were higher in non-rapid cycling (NRC) than in RC (p = 0.010), no significant difference was found between NRC and RC in age, gender proportion, education, marriage status, psychotic features, atypical features, comorbidity of thyroid diseases, substance abuse, HAMD-17 total scores, BMI, style of current episode, duration of illness and psychopharmaceutical treatment (p > 0.05)
The association between antithyroid antibodies and RC In this study, we found that both TPO-abs and thyroglobulin antibodies (Tg-abs) were positively associated with RC, which was in line with Oomen’s report [22] that TPO-abs positivity was significantly associated with RCBD

Summary

Introduction

Conclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting. Previous studies suggest that the impact of antithyroid antibodies on mental wellbeing seems to be independent of thyroid function. We investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD). Both thyroid dysfunction and antithyroid antibodies have been widely reported to be associated with affective disorders. A large number of studies show that RCBD is associated with hypothyroidism [15,16,17,18,19]. A clinical research finds that TPO-abs are related to rapid cycling bipolar disorder [22]

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Results

Discussion

Conclusion