The Association between Autoimmune Thyroid Dysfunction and Rapid Cycling Bipolar Disorder

Background: It has long been established that abnormalities of thyroid function can cause neuropsychiatric symptoms. Hypothyroidism and depressed symptoms, as well as hyperthyroidism and manic/hypomanic symptoms, exhibit the most conspicuous connections. We aimed to determine the correlation between rapid cycling bipolar disorder (RCBD) and autoimmune thyroid dysfunction. This cross-sectional study included 200 psychiatric patients, both sexes, aged 18-35 years and diagnosed with BD. The studied patients were split up into two groups, group A (NRC group) comprised 125 patients with non-rapid cycling bipolar disorder, and group B (RC group) included 75 psychiatric patients with RCBD. A questionnaire created by the researchers was utilized to gather general sociodemographic and clinical data. The diagnostic and statistical manual of mental disorders, fifth edition (DSM-5) was utilized to conduct the diagnostic evaluation.Subjects and Methods: A cross-sectional study was conducted on 200 bipolar disorder (BD) patients aged 18–35, with diagnostic assessment based on DSM-5 and exclusion criteria for comorbid conditions and recent pregnancy or substance use. Patients were categorized into rapid cycling (RC) and non-rapid cycling (NRC) groups, with thyroid function and antithyroid antibody levels assessed using CLIA-based lab tests and symptom severity was evaluated using the Young Mania Rating Scale and HAMD-17.Results: Univariate logistic regression analysis revealed that comorbidity of thyroid diseases, thyroglobulin antibodies (Tg-abs) positivity and antithyroid peroxidase antibodies (TPO-Abs) positivity were significant predictors for diagnosis of RCBD, as there is a significant association between RCBD and comorbidity of thyroid diseases, Tg-abs positivity and TPO-abs positivity (P<0.05). Lithium treatment, Tg-abs positivity TPO-abs positivity and TPO-abs positivity were significant predictors for thyroid dysfunction, as there is a significant connection between thyroid dysfunction and lithium treatment, TPO-abs positivity and Tg-abs positivity (P<0.05).Conclusions: There is a significant connection between RC and TPO-abs and Tg-abs, rather than hypothyroidism or hyperthyroidism; this association is not influenced by thyroid disease. Unlike Tg-abs, TPO-abs is connected to hyperthyroidism. While there is a strong correlation between TPO-abs and Tg-abs, TPO-abs appear to have a greater impact on the connection between RCBD and thyroid dysfunction.