Antithyroid antibody-linked symptoms in borderline personality disorder

Circulating thyroid autoantibodies are more prevalent in patients with mood disorders than in the general population, but longitudinal clinical data that establish a relationship between thyroid antibody status and the course of any psychiatric syndrome have been lacking. In addition, scant attention has been paid to thyroid hormones and autoimmunity in borderline personality disorder (BPD). We report a case of a patient with classic BPD whose fluctuating mood and, especially, psychotic symptoms-rated using a double-blind method-were directly linked to antithyroglobulin antibody titers serially determined over an inpatient period of 275 d. Significantly lower psychosis and depression ratings were seen during a 4-wk period of relatively low antithyroid antibody titers, during blinded treatment with carbamazepine, than were observed during two high autoantibody epochs. The significant positive correlations between nurse- and patient-rated depression and thyroid autoantibodies over the entire period of inpatient study were similar to those also observed between urinary free cortisol levels and depression; the positive correlation between antithyroglubulin antibody titers and psychotic symptoms was stronger (r = +0.544; p < 0.002). Although this patient had biochemical indices of primary hypothyroidism, she showed only marginal improvement to triiodothyronine (T3) and no apparent clinical response to sustained levorotatory thyroxine (T4) administration; neither were antithyroid antibody titers significantly associated with changes in T3, free T4, or thyroid-stimulating hormone concentrations. She clinically deteriorated during a 50-d fluoxetine trial. The present data demonstrate a clinically significant, longitudinal correlation between fluctuating antithyroid antibody titers and symptoms of borderline psychopathology in our patient. It will be of interest to determine the prevalence, pathophysiologic mechanisms, and treatment implications of this putative autoimmune- BPD link.