The seroprevalence of antithyroid peroxidase antibodies in bipolar families and bipolar twins: results from two longitudinal studies

Predominant polarity in bipolar affective disorder and its impact on cognition and quality of life

Background

Bipolar mood disorder or bipolar affective disorder (BPAD) is a chronic illness characterized by phases of mania/hypomania, depression, or mixed episodes. The course of bipolar mood disorder is relapsing in nature. It is associated with high comorbidity rates, a large number of premature deaths due to suicide, and a worse social and work performance. All of those characteristics entail a significant economic impact due to both direct and indirect costs and require an effective diagnostic and therapeutic approach. Lifetime prevalence of BPAD is approximately 4% worldwide. Various attempts have been made to define "predominance" of polarity in BPAD.

Need for this Study

Our study tries to highlight the existence of predominant polarity by comparing effects of the same on substance consumption, cognitive abilities, quality of life, and preponderance of specific polarity to specific gender.

Method

After Institutional Ethics Committee Approval and written informed consent, patients who were diagnosed with BPAD attending out-patient department of a tertiary care hospital in Mumbai were recruited. A total of 57 participants were enrolled. The World Health Organization Quality of Life - Brief Scale (WHOQOL BREF) and the Montréal Cognitive Assessment (MoCA) were both used to evaluate the patients' quality of life and cognitive ability, respectively.

Discussion and Results

Men exhibited manic predominant polarity, while women had depressive predominant polarity, with P value of. 003. Regarding age, illness length, education, substance abuse, family history, and suicide attempts, there was no discernible difference in the polarities. The outcome of female bipolar patients may be improved if the clinician is mindful of the burden of depression, risk of misdiagnosis, and variable therapy response. Interestingly, our study found no significant difference between MoCA scores of those with depressive and manic polarity. Substantial MoCA score differences were found between the groups with depressive polarity and no polarity.

Conclusion

Men were observed to experience more manic episodes. More women in the study experienced predominantly depressive polarity, highlighting the need to probe for a past history of hypomania or mixed episodes to avoid misdiagnosis as unipolar depression in them. Manic predominate polarity performed better in the physical and psychological domains of the post hoc test for quality-of-life BREF scale. There were substantial MoCA score differences between the groups with depressive polarity and no polarity, with the depressive polarity showing more cognitive decline.

No association between anti-thyroidperoxidase antibodies and bipolar disorder: a study in the Dutch Bipolar Cohort and a meta-analysis

BACKGROUND

Thyroid autoimmunity has been associated with bipolar disorder (BD). However, results from previous studies on the seroprevalence of anti-thyroid peroxidase antibodies (TPO-abs) in BD are inconsistent.

OBJECTIVES

The aim of the present study is to investigate whether the seroprevalence and titer levels of TPO-abs are related to BD.

METHOD

TPO-abs were measured in plasma samples of 760 patients with bipolar disorder, 261 first-degree relatives and 363 controls by enzyme-linked immunosorbent assay (ELISA). To address methodological limitations of previous studies, we assessed clinical characteristics with several (self-reported) questionnaires to investigate whether TPO-abs positivity is related to particular clinical subgroups of BD patients. We performed an additional meta-analysis of seroprevalences of TPO-abs in BD patients including data from present and previous studies.

RESULTS

Seroprevalence or titer levels of TPO-abs did not significantly differ between patients with BD, their first-degree relatives, and controls. In BD patients, the prevalence of TPO-abs was unrelated to specific clinical factors, including lithium use. Our meta-analysis of twelve studies showed an overall odds ratio of 1.3 (CI 95 %: 0.7-2.3; p = 0.30), reaffirming the absence of an association of BD with TPO-abs.

CONCLUSIONS

In the largest study of TPO-abs in BD to date, our findings indicate that TPO-abs are not associated with (the risk for) bipolar disorder.

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

BACKGROUND

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. Here, we investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD).

METHODS

Fast 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.

RESULTS

Neither 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.

CONCLUSION

TPO-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.

The Link between Thyroid Autoimmunity, Depression and Bipolar Disorder

Depression and bipolar disorder are two major psychiatric illnesses whose pathophysiology remains elusive. Newly emerging data support the hypothesis that the dysfunction of the immune system might be a potential factor contributing to the development of these mental disorders. The most common organ affected by autoimmunity is the thyroid; therefore, the link between autoimmune thyroid disorders and mental illnesses has been studied since the 1930s. The aim of this review is to discuss the associations between thyroid autoimmunity, depression and bipolar disorder.