Anti-thyroid Antibodies Linked to Depression
The case study, Depression, anti-thyroid antibodies and Hashimoto encephalopathy, states “Literature shows that a close link exists between depression and antithyroid antibodies whatever thyroid status.” It also suggests, “a psychiatric report should systematically be added to the clinical and biological findings in order to make a better approach of the existing links between depression and other manifestations of the disease.”
The case study from 1985, Antithyroid antibodies in depressed patients, states ” The presence of antithyroid (antimicrosomal and antithyroglobulin) antibodies was assessed in 45 psychiatric inpatients with prominent depressive symptoms (28 with DSM-III major depression). Nine patients (20%) had detectable titers of antithyroid antibodies, a rate considerably higher than the 5%-10% observed in the normal population.”
Another research article, The link between thyroid autoimmunity (antithyroid peroxidase autoantibodies) with anxiety and mood disorders in the community: a field of interest for public health in the future, indicates “individuals in the community with thyroid autoimmunity may be at high risk for mood and anxiety disorders.” The results of the study were that 16% of the overall sample had an anti-TPO value above the normal cut-off. Subjects with at least one diagnosis of anxiety disorders or mood disorders were positive for serum anti-TPO more frequently than subjects without mood or anxiety disorders.
Those patients with high antibody levels who do have a mood disorder being treated by lithium should be monitored. The case study, Lithium-induced Hashimoto’s encephalopathy: a case report, indicates “RESULTS: Lithium clearly relieved the patient’s depressive symptoms, but after 40 days encephalopathy developed. Thyrotoxicosis was ruled out, and serum antithyroid antibody titers were elevated. In the cerebrospinal fluid, protein content was substantially elevated and antithyroid antibodies were detected. Encephalopathy resolved dramatically after course of intravenous pulse therapy with methylprednisolone. CONCLUSIONS: We believe that autoantibodies against antigens shared by the thyroid gland and the brain were induced by exposure to lithium, causing the patient to develop Hashimoto’s encephalopathy.”
My ending thoughts on this post:
This research on the link between high anti-thyroid antibodies and mood disorders appears to have been well documented since the 80’s at the latest. Anxiety and depression can cause symptoms similar to HE symptoms. When doctors are evaluating HE patients after treatment, anxiety or depression symptoms could be masking the true effectiveness of the treatment of HE. Considering the link between anti-thyroid antibodies and mood disorders and the finding that HE patients are at high risk for developing depression and anxiety, each HE patient exhibiting anxiety or depression symptoms should be seen by a psychiatrist to screen for depression or anxiety.