Decreased thyroid function in Korean women with bipolar disorder receiving valproic acid

Quetiapine-Induced Thyroid Dysfunction: A Systematic Review

Thyroid abnormalities are documented consequences of quetiapine treatment. This may have clinical implications as changes in thyroid hormones may deteriorate a person's affective state. Yet less is known about the clinical factors and underlying mechanisms associated with thyroid hormones on quetiapine therapy. We therefore systematically reviewed the published literature of evidence of quetiapine-induced thyroid abnormalities. We searched MEDLINE, PsycINFO, Google Scholar, and EMBASE for articles in which individuals developed biochemically confirmed thyroid abnormalities (with or without clinical symptoms) while on quetiapine treatment. We included case reports, case series, observational, and experimental studies. We included 32 studies, 20 of which were observational and experimental studies. There were 10 case reports and 1 case series. All the research designs suggested an association between quetiapine and hypothyroidism. However, these findings were limited by the quality of the included studies and the general lack of either a clear temporal relationship or dose response. Quetiapine has been associated with thyroid abnormalities, mainly with hypothyroidism. Drug imputability in these abnormalities is not always clear, and the underlying pathophysiology may include immunological and nonimmunological mechanisms. Large prospective studies are required to clarify this association and to further inform the management of patients treated with quetiapine where hypothyroidism occurs.

Lithium-associated hypothyroidism and potential for reversibility after lithium discontinuation: Findings from the LiSIE retrospective cohort study

BACKGROUND

The association between lithium and thyroid dysfunction has long been known. However, it remains unknown if lithium-associated hypothyroidism is reversible once lithium treatment has been stopped.

AIMS

To determine whether lithium-associated hypothyroidism was reversible in patients who subsequently discontinued lithium.

METHODS

A retrospective cohort study in the Swedish region of Norrbotten into the effects and side- effects of lithium treatment and other drugs for relapse prevention (Lithium - Study into Effects and Side Effects). For this particular study, we reviewed medical records between 1997 and 2015 of patients with lithium-associated hypothyroidism who had discontinued lithium.

RESULTS

Of 1340 patients screened, 90 were included. Of these, 27% had overt hypothyroidism at the start of thyroid replacement therapy. The mean delay from starting lithium to starting thyroid replacement therapy was 2.3 years (SD 4.7). In total, 50% of patients received thyroid replacement therapy within 10 months of starting lithium. Of 85 patients available for follow-up, 41% stopped thyroid replacement therapy after lithium discontinuation. Only six patients reinstated thyroid replacement therapy subsequently. Of these, only one had overt hypothyroidism.

CONCLUSIONS

Lithium-associated hypothyroidism seems reversible in most patients once lithium has been discontinued. In such cases, thyroid replacement therapy discontinuation could be attempted much more often than currently done. Based on the limited evidence of our study, we can expect hypothyroidism to recur early after thyroid replacement therapy discontinuation, if at all.

Hypothyroidism risk compared among nine common bipolar disorder therapies in a large US cohort

OBJECTIVES

Thyroid abnormalities in patients with bipolar disorder (BD) have been linked to lithium treatment for decades, yet other drugs have been less well studied. Our objective was to compare hypothyroidism risk for lithium versus the anticonvulsants and second-generation antipsychotics commonly prescribed for BD.

METHODS

Administrative claims data on 24,574 patients with BD were analyzed with competing risk survival analysis. Inclusion criteria were (i) one year of no prior hypothyroid diagnosis nor BD drug treatment, (ii) followed by at least one thyroid test during BD monotherapy on lithium carbonate, mood-stabilizing anticonvulsants (lamotrigine, valproate, oxcarbazepine, or carbamazepine) or antipsychotics (aripiprazole, olanzapine, risperidone, or quetiapine). The outcome was cumulative incidence of hypothyroidism per drug, in the presence of the competing risk of ending monotherapy, adjusted for age, sex, physician visits, and thyroid tests.

RESULTS

Adjusting for covariates, the four-year cumulative risk of hypothyroidism for lithium (8.8%) was 1.39-fold that of the lowest risk therapy, oxcarbazepine (6.3%). Lithium was non-statistically significantly different from quetiapine. While lithium conferred a higher risk when compared to all other treatments combined as a group, hypothyroidism risk error bars overlapped for all drugs. Treatment (p = 3.86e-3), age (p = 6.91e-10), sex (p = 3.93e-7), and thyroid testing (p = 2.79e-87) affected risk. Patients taking lithium were tested for hypothyroidism 2.26-3.05 times more frequently than those on other treatments.

CONCLUSIONS

Thyroid abnormalities occur frequently in patients with BD regardless of treatment. Therefore, patients should be regularly tested for clinical or subclinical thyroid abnormalities on all therapies and treated as indicated to prevent adverse effects of hormone imbalances on mood.

Thyroglobulin antibodies and risk of readmission at one year in subjects with bipolar disorder

Thyroid autoimmunity has been proposed as an endophenotype for Bipolar Disorder (BD), although its relationship with clinical outcomes remains unclear. We aimed to determine whether thyroid autoimmune status (thyroperoxidase antibodies [TPO-Abs] and thyroglobulin antibodies [TG-Abs]) in BD is associated with a greater risk for readmission at one year. We studied 77 inpatients with BD admitted for an index manic or mixed episode. Serum thyroid antibodies (TPO-Abs and TG-Abs) were determined at admission. We compared the readmission risk at 1 year, based on patients׳ thyroid autoimmunity profile using survival analyses. Cox regression was used to control covariates. TG-Abs+ but not TPO-Abs+ was associated with a lower risk of relapse. The Kaplan-Meier mean estimated survival times were 341.6 days (CI95% 316.4-366.8) for the TG-Abs+ group and 261.9 days (CI95%: 221.8 to 302.0) for the TG-Abs- group. Cox proportional hazards regression indicated that subjects with TG-Abs+ were 3.7 (1/OR=1/0.27) times less likely to get admitted during the follow-up period than those with TG-Abs-. Our study suggests that an autoimmune biomarker in patients with BD (i.e., the presence of TG-Abs) is associated with a lower risk of psychiatric readmission after an index hospitalization for a manic or mixed episode.