Adjunctive thyroid hormone treatment in rapid cycling bipolar disorder: A double-blind placebo-controlled trial of levothyroxine (L-T4 ) and triiodothyronine (T3 )

Lithium, the gold standard drug for bipolar disorder: analysis of current clinical studies

Lithium is the gold standard drug in the treatment of bipolar disorder. Despite increasing scientific interest, relatively few patients with bipolar disorder receive lithium therapy. Lithium is the only drug that is effective in the prophylaxis of manic, depressive, and suicidal symptoms. Lithium therapy is also associated with a variety of adverse drug reactions and the need for therapeutic drug monitoring. Numerous studies have focussed on the efficacy and safety of both lithium-monotherapy and lithium-add-on therapy. The aim of this study is to provide a systematic overview of clinical studies on lithium therapy for bipolar disorder from the last 7 years and to present a critical analysis of these studies. The results provide an up-to-date overview of the efficacy, tolerability, and safety of lithium therapy for bipolar disorder and thus improve the pharmacotherapy of bipolar disorder. A total of 59 studies were analysed using various analysis parameters. The studies were also categorised into different subgroups. These are lithium-monotherapy, lithium vs. placebo/drug, and lithium + adjunctive therapy. The majority of the studies (N = 20) had a duration of only 3-8 weeks. Only 13 studies lasted for > 40 weeks. Lithium was superior to aripiprazole, valproic acid, and quetiapine in terms of improving manic symptoms. Lithium therapy resulted in a lower relapse rate compared to valproic acid therapy. Lithium was more neuroprotectively effective than quetiapine. Fourteen of the 22 add-on therapies to lithium showed a predominantly positive effect on the treatment outcome compared to lithium-monotherapy. Only the add-on therapy with sertraline led to a higher rate of study discontinuations than lithium-monotherapy. Lithium is a safe and effective treatment option for children. However, risperidone and quetiapine were superior to lithium in some aspects, which is why these drugs should be considered as an alternative treatment option for children. Collectively, current clinical studies highlight the relevance of lithium in the treatment of bipolar disorder.

Thyroid hormone levels in patients with bipolar disorder: a systematic review and meta-analysis

PURPOSE

To investigate the difference in blood (serum/plasma) thyroid hormone (TH) levels, including thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3), in bipolar disorder (BD) during different mood episodes (depression and mania) compared with healthy control (HC) and between manic episodes (BD-M) and depressive episodes (BD-D).

METHODS

As of September 1, 2024, the electronic databases PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, China Science and Technology Journal Database, Wanfang Database, and Clinical Trials. Gov were systematically searched with no language limitations. Standardized mean differences (SMD) with 95% confidence interval (CI) were summarized using a random effects model. The chi-squared-based Q test and the I2 test assessed the size of heterogeneity.

RESULTS

The 21 studies included a total of 3696 participants, Of the 2942 BD patients, 1583 were in depressive episodes 1359 were in manic episodes. The status of measuring blood TH levels included 2 studies in plasma and 19 in serum. Combined with the results of the sensitivity analyses, we obtained the following relatively reliable results: serum T3 (SMD: -0.63, 95%CI: -1.09 to -0.17) and FT3 (SMD: -0.42, 95%CI: -0.83 to -0.00) levels decreased significantly in BD-D compared to HC; serum T3 (SMD: -0.91, 95%CI: -1.49 to -0.32) levels decreased significantly and serum FT4 (SMD: 0.37, 95%CI: 0.14 to 0.60) levels increased significantly in BD-M than in HC; serum T3 (SMD: 0.87, 95%CI: 0.24 to 1.49) and FT3 (SMD: 0.27, 95%CI: 0.13 to 0.42) levels demonstrated a significant elevation in BD-M compared to BD-D. In the group of euthyroidism, apart from serum FT4 (SMD: 0.21, 95%CI: -0.15 to 0.58) levels showed no significant difference between BD-M and HC, other results above remained consistent.

CONCLUSION

Serum T3 and FT3 levels decreased significantly in BD-D compared to HC. Serum T3 levels decreased significantly and serum FT4 levels increased significantly in BD-M compared to HC. Serum T3 and FT3 levels increased significantly in BD-M than in BD-D. The temporality of changes in TH levels and BD progression demands further longitudinal studies to illustrate.

TRIAL REGISTRATION

Number and date of registration for prospectively registered trials No. CRD42022378530.

The Causal Role of Thyroid Hormones in Bipolar Disorders: A Two-Sample Mendelian Randomization Study

INTRODUCTION

Bipolar disorder is a complex psychiatric condition with distinctions between clinical subtypes including Type 1 and 2 disorders. Several studies have proposed that thyroid hormones may be involved in the aetiology of bipolar disorders.

METHODS

This study employed a two-sample Mendelian randomization (MR) approach to investigate the causal relationships between six thyroid hormone metrics (TSH, FT4, FT3, TT3, FT3/FT4 and TT3/FT4) and bipolar disorder and Type 1 and 2 disorders, separately. Genome-wide association (GWAS) data from the ThyroidOmics Consortium (up to 271,040 individuals of European ancestry) were used for thyroid function metrics. Bipolar disorder GWAS data included 41,917 cases and 371,549 controls (25,060 Type 1 and 6,781 Type 2 cases). We applied inverse variance weighted (IVW) methods for primary MR analysis, with MR Egger, weighted median and weighted mode for sensitivity. Additional tests assessed horizontal pleiotropy and heterogeneity.

RESULTS

Higher FT4 levels showed a protective causal effect against bipolar disorder (OR: 0.92, 95% CI: 0.86-0.97, p = 4.58 × 10-3) and a suggestive effect on Type 1 disorders (OR: 0.92, 95% CI: 0.86-0.99, p = 3.21 × 10-2). Elevated FT3 (OR: 1.18, 95% CI: 1.03-1.35, p = 1.55 × 10-2) and FT3/FT4 ratio (OR: 1.97, 95% CI: 1.02-3.82, p = 4.46 × 10-2) had suggestive harmful effects on Type 1 disorders. Sensitivity analyses showed consistent effects, with no significant horizontal pleiotropy or heterogeneity.

CONCLUSIONS

These findings highlight the protective role of FT4 and the potentially harmful effect of elevated FT3 in Type 1 bipolar disorder, highlighting the need for further research on thyroid hormone levels as a potential treatment strategy for Type 1 bipolar disorder.

Association between hypothyroidism subtypes and major depression: A two-sample Mendelian randomization study

BACKGROUND

The causal relationship between different hypothyroidism subtypes and the risk of major depression (MD) is yet to be fully elucidated. This study aimed to determine if there's a causal relationship between various hypothyroidism subtypes (and related factors) and the risk of MD.

METHODS

This genetic association study utilized a two-sample Mendelian Randomization (MR) approach to explore the causal relationships between various hypothyroidism subtypes and MD risk. Genome-Wide Association Study (GWAS) summary statistics were obtained from the FinnGen and the UK Biobank. Instrumental variables (IVs) were chosen based on single nucleotide polymorphisms (SNPs).

RESULTS

Among the analyzed hypothyroidism subtypes and related factors, "Hypothyroidism, strict autoimmune" (HTCBSA) and "Hypothyroidism, levothyroxin purchases" (HT/LP) demonstrated a statistically significant positive causal relationship with MD, with odds ratios of 1.020 (95 % CI: 1.004-1.037) and 1.022 (95 % CI: 1.005-1.040), respectively. The sensitivity analysis supported the robustness of these findings, showing no significant horizontal pleiotropy and confirming the stability of results when individual SNPs were removed. "Congenital iodine-deficiency syndrome/hypothyroidism" (CIDS/HT), "Postinfectious hypothyroidism" (PHT), "Hypothyroidism due to medicaments and other exogenous substances" (HDTDM and OES), "Thyroid Stimulating Hormone" (TSH), "Thyrotropin-releasing hormone" (THRH), and "Hypothyroidism, strict autoimmune, 3 medication purchases required" (HTCBSA/3MPR) showed no significant causal relationship with MD.

LIMITATIONS

The study population was limited to individuals of European ancestry, and there may be certain genetic differences between different ethnic groups.

CONCLUSIONS

This MR study suggests a potential causal relationship between certain hypothyroidism subtypes (specifically HTCBSA and HT/LP) and an increased risk of MD.

Association of major depression, schizophrenia and bipolar disorder with thyroid cancer: a bidirectional two-sample mendelian randomized study

BACKGROUND

Major depressive disease (MDD), schizophrenia (SCZ), and bipolar disorder (BD) are common psychiatric disorders, and their relationship with thyroid cancer has been of great interest. This study aimed to investigate the potential causal effects of MDD, SCZ, BD, and thyroid cancer.

METHODS

We used publicly available summary statistics from large-scale genome-wide association studies to select genetic variant loci associated with MDD, SCZ, BD, and thyroid cancer as instrumental variables (IVs), which were quality controlled and clustered. Additionally, we used three Mendelian randomization (MR) methods, inverse variance weighted (IVW), MR-Egger regression and weighted median estimator (WME) methods, to estimate the bidirectional causal relationship between psychiatric disorders and thyroid cancer. In addition, we performed heterogeneity and multivariate tests to verify the validity of the IVs.

RESULTS

We used two-sample bidirectional MR analysis to determine whether there was a positive causal association between MDD and thyroid cancer risk. The results of the IVW analysis (OR = 3.956 95% CI = 1.177-13.299; P = 0.026) and the WME method (OR = 5.563 95% CI = 0.998-31.008; P = 0.050) confirmed that MDD may increase the risk of thyroid cancer. Additionally, our study revealed a correlation between genetic susceptibility to SCZ and thyroid cancer (OR = 1.532 95% CI = 1.123-2.088; P = 0.007). The results of the WME method analysis based on the median estimate (OR = 1.599 95% CI = 1.014-2.521; P = 0.043) also suggested that SCZ may increase the risk of thyroid cancer. Furthermore, our study did not find a causal relationship between BD and thyroid cancer incidence. In addition, the results of reverse MR analysis showed no significant causal relationships between thyroid cancer and MDD, SCZ, or BD (P > 0.05), ruling out the possibility of reverse causality.

CONCLUSIONS

This MR method analysis provides new evidence that MDD and SCZ may be positively associated with thyroid cancer risk while also revealing a correlation between BD and thyroid cancer. These results may have important implications for public health policy and clinical practice. Future studies will help elucidate the biological mechanisms of these associations and potential confounders.

The effect of neuroendocrine abnormalities on the risk of psychiatric readmission after hospitalization for bipolar disorder: A retrospective study

BACKGROUND

The correlation between the endocrine system and bipolar disorder(BD) has been well recognized, yet the influence of neuroendocrine hormones on readmission risk post-hospitalization for BD remains largely unexplored. This retrospective cohort study was to scrutinize the impact of neuroendocrine functionality on the readmission of patients with BD post-hospitalization for mental disorders.

METHODS

The dataset was derived from the electronic medical records of the First Affiliated Hospital of Jinan University in Guangzhou, China. Both univariate and multivariate logistic regression analysis were conducted on all patients hospitalized for BD, and from 1 January 2017 to October 2022.

RESULTS

Of the 1110 eligible patients, 83 and 141 patients experienced psychiatric readmissions within 90 and 180 days post-discharge, respectively. Multivariate analysis revealed that high serum TSH levels (aOR = 1.079; 95%CI = 1.003-1.160) and thyroid disease comorbidities (aOR = 2.899; 95%CI = 1.303-6.452) were independently correlated with the risk of 90-day readmission; while increased serum TSH levels (aOR = 1.179; 95%CI = 1.081-1.287) represented a risk factor for 180-day readmission. These results indicate that high serum TSH levels and thyroid disease comorbidities may contribute to an elevated readmission risk in patients with BD following hospitalization.

CONCLUSION

Routinely evaluating and intervening in thyroid function is crucial in the treatment of BD, as it may aid in preventing re-hospitalization.

Current Status and Treatment of Rapid Cycling Bipolar Disorder

BACKGROUND

Rapid cycling (RC) at least 4 recurrent episodes per year in bipolar disorder (BD) has been recognized since the 1970s. We now comment on our recent review of the topic and extensive RC analysis in a large clinical cohort, emphasizing therapeutics research.

COMMENTS

Prevalence of RC-BD averages 36% for any year versus 22% in the preceding year. Rapid cycling is not a consistent feature over many years, although average long-term, annual recurrence rates are greater in RC-BD patients. Risk of RC may be somewhat greater among women and with older ages. It is also associated with cyclothymic temperament, prominent depression, and mood-switching with antidepressant treatment and is associated with increased suicidal risk. Treatment of individual episodes in RC-BD and effective long-term prevention remain inadequately studied, although antidepressant treatment can worsen RC. Some research supports treatment with aripiprazole, lamotrigine, and lithium, and interest in second-generation antipsychotics is emerging. All such options are used in various inadequately evaluated combinations.

CONCLUSIONS

Rapid cycling is prevalent among BD patients but seems to vary in risk over time without evidence of progressive worsening. Treatment of acute episodes in RC-BD patients and effective long-term preventive management require much more intensive investigation.

Low and very low lithium levels: Thyroid effects are small but still require monitoring

AIM

Low doses of lithium, as might be used for mood or dementia prevention, do not carry the same renal, toxicity, and tolerability problems of doses used for prophylaxis or treatment of mania. However, thyroid effects of low doses have not been investigated. Our goal in this study was to assess the changes in thyroid-stimulating hormone (TSH) associated with a broad range of lithium levels, including those well below the therapeutic range for bipolar disorders.

METHODS

This study was conducted in a small healthcare system with 19 associated primary care clinics served by a Collaborative Care program of psychiatric consultation. In this retrospective review of electronic records, we searched for patients who had received a lithium prescription and both pre- and post-lithium thyroid-stimulating hormone (TSH) levels.

RESULTS

Patients with low lithium levels (<0.5 mEq/L, N = 197) had a mean thyroid-stimulating hormone (TSH) increase of 0.52 mIU/L. Patients with maintenance lithium levels (0.5-0.8 mEq/L; N = 123) had a mean TSH increase of 1.01 mIU/L; and patients with antimanic lithium levels (>0.8 mEq/L; N = 79) had a mean TSH increase of 2.16 mIU/L. The probability of TSH exceeding the upper limit of normal in our laboratory (>4.2 mIU/L) was positively associated with pre-lithium TSH.

CONCLUSION

These results suggest that the risk of lithium-induced hypothyroidism is dose-related, and relatively small with very low doses, but thyroid monitoring, including a pre-lithium TSH, is still warranted.

Differences in Symptoms Following Acupuncture Treatment in Three Case Presentations of Bipolar Disorder: Type 2, Comorbid Anxiety Disorder, and Rapid Cycling Type

Background

This study reports the effects of acupuncture treatment on depression and anxiety symptoms for 3 different bipolar disorder (BD) pathologies.

Case

Case 1: A 35-year-old man was diagnosed with BD type 2. His depressive symptoms appeared 17 years ago. He did not meet the diagnostic criteria for anxiety disorder (AD) in the Mini International Neuropsychiatric Interview (MINI). Case 2: A 32-year-old woman was diagnosed with BD type 2 with AD. Her depressive symptoms appeared 5 years ago. MINI indicated panic-, social anxiety-, and generalized AD. Case 3: A 42-year-old woman was diagnosed with rapid cycling BD. She developed depressive and hypomanic symptoms and visited our hospital 18 years ago. Acupuncture treatment was performed weekly for 12 weeks. Depression and anxiety symptoms were evaluated using the Himorogi Self-Rating Depression Scale (HSDS) and Himorogi Self-Rating Anxiety Scale (HSAS), respectively.

Results

Case 1: The HSAS score did not improve significantly, but the HSDS score decreased from 22 points at baseline to 9 points at the 12th visit. Case 2: The HSDS score did not improve, and the HSAS score remained high from 26 points at baseline to 25 points at the 12th visit. Case 3: During the acupuncture period, both HSDS and HSAS scores fluctuated greatly, and the patient experienced repeated episodes of depression and hypomania.

Conclusions

The response to acupuncture treatment may differ according to the classification and pathology of BD, and it may be desirable to perform the acupuncture treatment after evaluating the pathology and estimating the prognosis.

Prevalence and outcomes of rapid cycling bipolar disorder: Mixed method systematic meta-review

Rapid-cycling in bipolar disorder (RC-BD) is associated with greater illness morbidity and inferior treatment response but many aspects remain unclear, prompting this systematic review of its definitions, prevalence, and clinical characteristics. We searched multiple literature databases through April 2022 for systematic reviews or meta-analyses on RC-BD and extracted associated definitions, prevalence, risk-factors, and clinical outcomes. We assessed study quality (NIH Quality Assessment Tool) and levels of evidence (Oxford criteria). Of 146 identified reviews, 22 fulfilling selection criteria were included, yielding 30 studies involving 13,698 BD patients, of whom 3777 (27.6% [CI: 26.8-28.3]) were considered RC-BD, as defined in 14 reports by ≥4 recurrences/year within the past 12 months or in any year, without considering responsiveness to treatment. Random-effects meta-analytically pooled one-year prevalence was 22.3% [CI: 14.4-32.9] in 12 reports and lifetime prevalence was 35.5% [27.6-44.3] in 18 heterogenous reports. Meta-regression indicated greater lifetime prevalence of RC-BD among women than men (p=0.003). Association of RC-BD with suicide attempts, and unsatisfactory response to mood-stabilizers was supported by strong evidence (Level 1); associations with childhood maltreatment, mixed-features, female sex, and type-II BD had moderate evidence (Level 2). Other factors: genetic predisposition, metabolic disturbances or hypothyroidism, antidepressant exposure, predominant depressive polarity (Level 3), along with greater illness duration and immune-inflammatory dysfunction (Level 4) require further study. RC-BD was consistently recognized as having high prevalence (22.3%-35.5% of BD cases) and inferior treatment response. Identified associated factors can inform clinical practice. Long-term illness-course, metabolic factors, and optimal treatment require further investigation.

Case report: rTMS in combination with aripiprazole and sodium valproate for the maintenance treatment of rapid cycling bipolar disorder

As a safe neuromodulation therapy, rTMS is applied to treat a variety of psychiatric and neurological disorders. Additionally, both aripiprazole and sodium valproate are effective in the treatment of rapid cycling bipolar disorder. This case reports a female patient with a 17-year history of bipolar disorder who developed rapid-circulation bipolar disorder 5 years prior to presentation. After combined treatment with rTMS, aripiprazole, and sodium valproate, the patient’s mood remained stable and she was able to live and work normally.

The Wistar Kyoto Rat: A Model of Depression Traits

There is an ongoing debate about the value of animal research in psychiatry with valid lines of reasoning stating the limits of individual animal models compared to human psychiatric illnesses. Human depression is not a homogenous disorder; therefore, one cannot expect a single animal model to reflect depression heterogeneity. This limited review presents arguments that the Wistar Kyoto (WKY) rats show intrinsic depression traits. The phenotypes of WKY do not completely mirror those of human depression but clearly indicate characteristics that are common with it. WKYs present despair- like behavior, passive coping with stress, comorbid anxiety, and enhanced drug use compared to other routinely used inbred or outbred strains of rats. The commonly used tests identifying these phenotypes reflect exploratory, escape-oriented, and withdrawal-like behaviors. The WKYs consistently choose withdrawal or avoidance in novel environments and freezing behaviors in response to a challenge in these tests. The physiological response to a stressful environment is exaggerated in WKYs. Selective breeding generated two WKY substrains that are nearly isogenic but show clear behavioral differences, including that of depression-like behavior. WKY and its substrains may share characteristics of subgroups of depressed individuals with social withdrawal, low energy, weight loss, sleep disturbances, and specific cognitive dysfunction. The genomes of the WKY and WKY substrains contain variations that impact the function of many genes identified in recent human genetic studies of depression. Thus, these strains of rats share characteristics of human depression at both phenotypic and genetic levels, making them a model of depression traits.

Thyroid Hormone Augmentation for Bipolar Disorder: A Systematic Review

Thyroid hormone (TH) augmentation, although commonly used for major depression, is sparingly used for bipolar disorder (BD) after the failure of mood-stabilizing agents. While the exact mechanisms of thyroid hormone action in BD remains unclear, central thyroid hormone deficit has been postulated as a mechanism for rapid cycling. This systematic review-conducted in accordance with the PRISMA guidelines-of eight studies synthesizes the evidence for TH augmentation in BD. A systematic search of the Ovid MEDLINE, Embase, PsycINFO, and Cochrane databases was conducted for randomized controlled trials (RCT), open-label trials, and observational studies of levothyroxine (LT4) and triiodothyronine (T3) for BD. Open-label studies of high dose LT4 augmentation for bipolar depression and rapid cycling showed improvement in depression outcomes and reduction in recurrence, respectively. However, an RCT of high-dose LT4 did not show benefit in contrast to placebo. An RCT comparing LT4, T3, and placebo showed benefit only in rapid-cycling bipolar women. A meta-analysis could not be completed due to significant differences in study designs, interventions, and outcomes. Our systematic review shows mixed evidence and a lack of high-quality studies. The initial promise of supratherapeutic LT4 augmentation from open-label trials has not been consistently replicated in RCTs. Limited data are available for T3. The studies did not report significant thyrotoxicosis, and TH augmentation were well tolerated. Therefore, TH augmentation, especially with supratherapeutic doses, should be reserved for highly treatment-resistant bipolar depression and rapid-cycling BD.

A New Treatment Protocol of Combined High-Dose Levothyroxine and Repetitive Transcranial Magnetic Stimulation for the Treatment of Rapid-Cycling Bipolar Spectrum Disorders: A Cohort Evaluation of 55 Patients

Background: Bipolar spectrum disorders (BSD) are highly disabling, with rapid cycling being treatment resistant. High-dose levothyroxine (HDT) has been reported to be effective. Diagnosis is associated with mutations in thyroid-activating enzymes and cerebral transporter protein carrier. Repetitive transcranial magnetic stimulation (rTMS) has neuroplastic effects. Methods: We report data on 55 severely symptomatic patients with rapid-cycling BSD treated with a combination protocol of HDT and rTMS. Of the patients, 31 patients (56.4%) were female and 40 (72.7%) had at least one additional diagnosis. Results: Patients were evaluated at three monthly intervals after acute treatment. Remission was measured using the Sheehan Disability Scale (SDS). The average number of medications prescribed was 1.8, with 32 patients (58.2%) needing only levothyroxine. The average dose of levothyroxine was 303.7 mcg (50 mcg−1000 mcg). A total of 53 patients were in remission (96.4%), with an average duration of 2.0 years. The SDS scores decreased significantly (Cohen’s d = 2.61 (95% C.I. 1.81 to 2.83, p < 0.001). One patient had reversible side effects. A total of 52 (94.3%) patients had Deiodinase 1 and 2 (DiO1/DiO2) or SLCO1C1 protein carrier gene mutations. Conclusion: The data support the safety and acceptability of combined HDT/rTMS. Patients achieved long remissions with substantial improvements in quality of life.

Evidence-based treatment strategies for rapid cycling bipolar disorder, a systematic review

OBJECTIVES

Rapid cycling is a phase of bipolar disorder with increased episode frequencies. It is a severe and disabling condition that often poses a major challenge to the clinician. The aim of this paper is to give an overview of the evidence-based treatment options for rapid cycling.

METHODS

A systematic search on Pubmed, Embase and Cochrane databases from inception until December 2021 was conducted according to the PRISMA guidelines. An additional search on clinicaltrials.gov was done. References of retrieved papers and key reviews were hand-searched. Randomized controlled trials including at least 10 patients with bipolar disorder, rapid cycling, reporting an objective outcome measure were selected.

RESULTS

Our search, initially revealing 1330 articles, resulted in 16 papers about treatment of an acute mood episode, relapse prevention or both. Lithium, anticonvulsants, second generation antipsychotics, antidepressants and thyroid hormone were assessed as treatment options in the presented data. Evidence supporting the use of aripiprazole, olanzapine, quetiapine, valproate and lamotrigine for treatment of rapid cycling bipolar disorder was found.

LIMITATIONS

Small sample sizes, different index episodes and variety of outcome measures.

CONCLUSION

Evidence regarding treatment of rapid cycling remains scarce. Evidence supports the use of aripiprazole, olanzapine, and valproate for acute manic or mixed episodes, quetiapine for acute depressive episodes and aripiprazole and lamotrigine for relapse prevention. Given the paucity of available evidence, and the burden that accompanies rapid cycling, future research is warranted.

Efficacy and safety of supraphysiologic doses of levothyroxine for patients with bipolar depression in adults: A systematic review

BACKGROUND

In bipolar disorder (BD), depression is the most difficult-to-treat dimension and available evidence suggests that add-on supraphysiological doses of levothyroxine may be an effective augmenting agent.

AIM

This systematic review has been conducted to evaluate the efficacy and safety of supraphysiologic doses of levothyroxine in bipolar depression in adults.

METHODS

After a comprehensive literature search on MEDLINE/PubMed, Scopus, Cochrane databases and International Clinical Trial Registry Platform (ICTRP), reviewers extracted data from eight relevant articles. PRISMA guidelines were followed in the selection, analysis and reporting of findings. Quality assessment was done using the risk of bias assessment and a random effects model was used to estimate effect size. Meta-analysis could not be done due to the lack of randomized, placebo-controlled trials and adequate data. A systematic review was done on eight studies and analysis on the pre-post change in Hamilton depression rating scale score (HDRS) was done for six studies.

RESULTS

The random model analysis of pooled effects showed a standardized mean difference of HDRS score by 2.62 (95% CI: 2.21-3.04; p < 0.0001). The responder and remission rates were not significant as reported in one study. Markov chain analysis performed in one study revealed that patients in the levothyroxine group had a significantly greater increase in time in the euthymic state and a decrease in the mixed state. In most of the studies, levothyroxine therapy was well tolerated, with no serious adverse events.

CONCLUSION

Add-on supraphysiological dose of levothyroxine has a potential role in attenuating depressive symptoms in bipolar depression, especially in therapy-resistant BD.

PROSPERO REGISTRATION NUMBER

CRD42020218456.

Relationship of free thyroxine and triiodothyronine on recurrence in maintenance therapy for bipolar depression

OBJECTIVE

To examine whether thyroid function in the normal range is associated with recurrence of depressive or mania in bipolar disorder patients.

METHODS

104 patients with bipolar disorder in maintenance therapy phase were assigned randomly to mood stabilizer combined with antidepressant group or mood stabilizer group. There were 52 patients in both groups respectively. Clinical symptoms were assessed at baseline, 3rd month, 6th month, 9th month, and 12th month using HAMD-17 and YMRS. Blood samples were analyzed for thyroid function.

RESULTS

There was no statistically significant difference of recurrence rate of depressive episode and mania episode at the end of the 12-months between mood stabilizer combined with antidepressant group and mood stabilizer group. There was significant relation of baseline TT4 (P = 0.020, HR = 0.948), FT3 (P = 0.035, HR = 2.055), and FT4 (P = 0.047, OR=0.769) with the recurrence of depressive episode in mood stabilizer group. The area under curve (AUC) of TT4, FT3, FT4 were 0.685, 0.613, 0.544, respectively. There was significant relation of baseline FT3 (P = 0.044，HR = 4.493) with the recurrence of mania episode for mood stabilizer combined with antidepressants group. The AUC of FT3 was 0.806.

CONCLUSION

Low level of TT4, FT4 and high level of FT3 within normal-range were related with the recurrence of depressive episode in the maintenance treatment with mood stabilizer of bipolar disorder. High level of FT3 within normal-range were related with recurrence of mania when mood stabilizer combined with antidepressants were used in the maintenance treatment of bipolar disorder.

Treatment-induced mood switching in affective disorders

Many patients under treatment for mood disorders, in particular patients with bipolar mood disorders, experience episodes of mood switching from one state to another. Various hypotheses have been proposed to explain the mechanism of mood switching, spontaneously or induced by drug treatment. Animal models have also been used to test the role of psychotropic drugs in the switching of mood states. We examine the possible relationship between the pharmacology of psychotropic drugs and their reported incidents of induced mood switching, with reference to the various hypotheses of mechanisms of mood switching.

Assessment of the relationships between genetic determinants of thyroid functions and bipolar disorder: A mendelian randomization study

BACKGROUND

Thyroid functions (TFs) have been implicated in the initiation and propagation of psychiatric disorders. Observational studies have shown associations of TFs with psychiatric disorders. However, the relationship between TFs and psychiatric diseases were still unclear.

METHODS

Genetic instruments for 6 TF-realted indexes, including free thyroxine (FT4), triiodothyronine (FT3):FT4 ratio, thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb) concentration, hypothyroidism, and hyperthyroidism, were obtained from several genome-wide association studies (GWASs). Their associations with BD were evaluated using Psychiatric Genomics Consortium (PGC) datasets (41,917 cases and 371,549 controls). All GWAS summary statitics were from European ancestry. Mendelian randomization (MR) estimates from each genetic instrument were combined using inverse variance weighted (IVW) meta-analysis, with complementary methods (eg, weighted median and MR Egger). We also multiple sensitivity analyses to examine horizontal pleiotropy and heterogeneity.

RESULTS

Genetically predicted level of FT4 was significantly associated with BD (odds ratio (OR)=0.89, 95% confidence interval (CI): 0.83-0.95; P=4.65 × 10-3), survived after the Bonferroni correction (P<0.05/6=0.008). Consistent directional effects for all sensitivity analyses were observed in the weighted median and MR Egger methods. Furthermore, our sensitive test suggested no significant horizontal pleiotropy (intercept=-0.01, P=0.12) and no notable heterogeneity (Q = 29.9; P=0.09). However, other TF indexes (FT3:FT4 ratio [OR=1.24, P=0.10], TSH [OR=1.01, P=0.61], TPOAb concentration [OR=1.20, P=0.54], hypothyroidism [OR=1.00, P=0.91], and hyperthyroidism [OR=0.99, P=0.57]) were not associated with BD.

CONCLUSIONS

Our results provide further evidence that higher FT4 level is associated with a reduced risk of BD, and suggest the importance of FT4 level in BD risk assessment and potential therapeutic targets development.

Rapid cycling bipolar disorder: Literature review on pharmacological treatment illustrated by a case report on ketamine

INTRODUCTION

Rapid cycling bipolar disorder (RCBD) is defined as four or more affective episodes (depression, mania or hypomania) within 1 year. RCBD has a high point of prevalence (from 10% to 20% among clinical bipolar samples) and is associated with greater severity, longer illness duration, worse global functioning and higher suicidal risk, but there is no consensus on treatment option. The use of several pharmacological agents has been reported (levothyroxine, antipsychotics, antidepressants and mood stabilizers).

OBJECTIVE

The main objective of this review was to propose a critical review of the literature and to rank the pharmacological agent using a level of evidence (LEO) adapted from the Center for Evidence-Based Medicine, and to illustrate it with a case report on off-label intravenous ketamine.

METHOD

We conducted a review using the MeSH terms and keywords (bipolar [Title/Abstract]) AND (rapid [Title/Abstract]) AND (cycling [Title/Abstract]) AND (treatment [Title/Abstract]). Alexis Bourla and Stéphane Mouchabac screened 638 documents identified through literature search in Medline (PubMed) or by bibliographic references and 164 abstracts were then analyzed. Nonpharmacological treatments were excluded.

RESULT

Seventy articles were included in the review and divided into six categories: mood stabilizers, antipsychotics, hormonal treatments, ketamine and other pharmacological treatments.

DISCUSSION

Our review highlights the heterogeneity of the pharmacological treatment of RCBD and no clear consensus can emerge.

A new approach for the treatment of subthreshold bipolar disorders: Targeted high dose levothyroxine and repetitive transcranial magnetic stimulation for mitochondrial treatment

Bipolar spectrum disorder includes Bipolar I, Bipolar II and subthreshold bipolar disorders (BD). The condition is highly prevalent, disabling and associated with high mortality. Failure of diagnosis is high. Subthreshold presentations present as 4 or more changes in polarity, are generally less responsive to standard treatment and as a result, drug combinations are often needed. High Dose Levothyroxine (HDT) has been reported to be safe and effective with this condition. Treatment response has been associated with mutations in thyroid activating enzymes and intra cerebral transporter protein carrier. Repetitive Transcranial Magnetic Stimulation (rTMS) has been shown to be effective in bipolar depression and has been proved to have neuroplastic effect. Present authors had reported clinical evidence of safe and effective use of a combination treatment protocol. Potential mechanisms of action of the combined treatment protocol and the role of mitochondria function are discussed.

Role of thyroid hormone therapy in depressive disorders

PURPOSE

The close association among thyroid metabolism, mood disorders and behavior has long been known. The old and modern uses of thyroid hormones to modulate the expression of depression and bipolar disorder and to improve clinical outcome when used in conjunction with psychotropic medications.

METHODS

A literature search was performed to identify studies investigating the effects of thyroid hormone treatment in patient s with mood disorders.

RESULTS

The successful modification of mood disorders with thyroid hormone underscores the association between endocrine and cerebral systems in these disorders. Thyroid hormones have a profound influence on behavior and appear to be capable of modulating the phenotypic expression of major mood disorders. In fact, there is evidence that triiodothyronine (LT3) may accelerate the antidepressant response to antidepressants, and studies suggest that LT3 also may augment the response to antidepressants in refractory depression. Add-on treatment with supraphysiologic doses of levothyroxine (LT4) has shown efficacy in open-label and in placebo-controlled studies, including in rapid cycling and prophylaxis-resistant bipolar disorder, and with acute refractory uni- or bipolar depression. Functional brain-imaging studies (PET) demonstrated that administration of supraphysiologic LT4 improves depressive symptoms in patients with bipolar depression by modulating cerebral activity in the anterior limbic network.

CONCLUSION

The add-on administration of supraphysiologic doses of LT4 is a promising strategy in patients with refractory bipolar and depressive mood disorders.

Patterns of Thyroid Hormone Prescription in Patients with Bipolar or Schizoaffective Disorder: Findings from the LiSIE Retrospective Cohort Study

The prescription of thyroid hormone replacement therapy (THRT) has increased in the general population; the thyroid stimulating hormone (TSH) threshold to initiate THRT has decreased. It remains unclear whether a similar trend has occurred in patients with bipolar disorder (BD). In this work we explore patterns and trends of prescribing THRT in patients with BD or schizoaffective disorder (SZD) with an observational study and time-trend analysis in the framework of the LiSIE (Lithium-Study into Effects and Side Effects) retrospective cohort study. In most patients, THRT was initiated for subclinical hypothyroidism. The median TSH at which THRT was started was 6.0 (IQR 4.0) mIU/L and the median free serum thyroxine (fT4) at which THRT was started was 11.8 (IQR 3.9) pmol/L. The median TSH concentration at the start of THRT decreased annually with 0.10 mIU/L (p = 0.047) and was higher in patients treated with lithium than in patients treated with other mood stabilisers (p = 0.02). In conclusion, THRT was typically initiated in the context of mild or absent alterations of thyroid function tests with a decreasing TSH threshold. As THRT is rarely reversed once initiated, clinicians need to weigh up potential benefits and risks when prescribing THRT for subclinical hypothyroidism in patients with BD or SZD.

Thyroid Function and Mood Disorders: A Mendelian Randomization Study

Background: Observational studies suggest that even minor variations in thyroid function are associated with the risk of mood disorders, including major depressive disorder (MDD) and bipolar disorder (BD). However, it is unknown whether these associations are causal or not. We used a Mendelian randomization (MR) approach to investigate causal effects of minor variations in thyrotropin (TSH) and free thyroxine (fT4) levels on MDD and BD risk. Materials and Methods: We performed two-sample MR analyses using data from the largest publicly available genome-wide association studies on normal-range TSH (n = 54,288) and fT4 (n = 49,269) levels, MDD (170,756 cases, 329,443 controls) and BD (20,352 cases, 31,358 controls). Secondary MR analyses investigated the effects of TSH and fT4 levels on specific MDD and BD subtypes. Reverse MR was also performed to assess the effects of MDD and BD on TSH and fT4 levels. Results: There were no associations between genetically predicted TSH and fT4 levels and MDD risk, nor MDD subtypes and minor depressive symptoms. A one standard deviation increase in fT4 levels was nominally associated with an 11% decrease in the overall BD risk (odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.80-0.98, p = 0.022) and a 13% decrease in the BD type 1 risk (OR = 0.87, CI = 0.75-1.00, p = 0.047). In the reverse direction, genetic predisposition to MDD and BD was not associated with TSH nor fT4 levels. Conclusions: Variations in normal-range TSH and fT4 levels have no effects on the risk of MDD and its subtypes, and neither on minor depressive symptoms. This indicates that depressive symptoms should not be attributed to minor variations in thyroid function. Borderline associations with BD and BD type 1 risks suggest that further clinical studies should investigate the effect of thyroid hormone treatment in BD.

Diagnosing and treating major depressive episodes that lie along the mood disorders spectrum: focus on depression with mixed features

Growing evidence indicates that historical descriptions of mixed depression-broadly defined as major depressive episodes with subthreshold manic or hypomanic (hypo/manic) symptoms-are incredibly clinically relevant in this day-and-age. However, the first operational definition of mixed depression did not occur in the modern nomenclature until 2013 with publication of Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), and there has not been enough time to evaluate these criteria empirically. Thus, the most valid operational definition of a mixed depressive episode is still unknown, widely accepted treatment guidelines are not available, and no treatment has regulatory approval for mixed depression-whether associated with bipolar I disorder, bipolar II disorder, or major depressive disorder. This is despite seven drugs having regulatory indications for mixed episodes, defined as the co-occurrence of syndromal depression and syndromal mania, and now recognized as mania with mixed features by DSM-5. Indeed, we found only two randomized, placebo-controlled trials in patients with protocol defined mixed depression, one with ziprasidone and one with lurasidone. Both studies were positive, suggesting treatment with second-generation antipsychotics may be helpful for mixed depressive episodes associated with bipolar II or unipolar disorder. We found no randomized control trial of antidepressant monotherapy in mixed depression and many clinical reports that such treatment may worsen mixed depression Randomized, placebo-controlled trials of antidepressants, antipsychotics, and mood stabilizers-alone and in combination-in individuals with carefully defined mixed depression are needed before firm treatment guidelines can be produced.

Hamlet's augury: how to manage discontinuation of mood stabilizers in bipolar disorder

Research has generated good quality evidence about the treatment and management of bipolar disorder in acute and, to some degree, sub-acute/continuation phases. This has informed various guidelines about the treatment and management of bipolar disorder (BD). However, for the long-term or maintenance phase of illness, most guidelines peter out and, in the absence of sufficiently high-quality research evidence, remain vague. This is particularly evident for the important clinical question of discontinuing mood stabilizing pharmacological agents after a period of remission has been achieved. The aim of this review is to put together current existing evidence about discontinuing mood stabilizers after a period of remission in order to come up with a structured and coherent strategy for managing such discontinuation and to make recommendations for future research. To this end, we reviewed the main relevant treatment guidelines and subsequent evidence following the publication of these guidelines. The current recommended long-term treatment of BD is usually considered within the same principles applicable to any chronic health condition (e.g. hypertension or diabetes) where the focus is on continuing treatment at minimum effective medication dose often life-long, switching to alternative choice of medication due to side-effects and very few, if any, indications for complete cessation. However, in the absence of strong evidence on long-term treatment and the high rate of non-concordance in BD, medication discontinuation is a very important aspect of the treatment that should be given due consideration at every aspect of the treatment.

Liothyronine and Desiccated Thyroid Extract in the Treatment of Hypothyroidism

Background: The basis for the treatment of hypothyroidism with levothyroxine (LT4) is that humans activate T4 to triiodothyronine (T3). Thus, while normalizing serum thyrotropin (TSH), LT4 doses should also restore the body's reservoir of T3. However, there is evidence that T3 is not fully restored in LT4-treated patients. Summary: For patients who remain symptomatic on LT4 therapy, clinical guidelines recommend, on a trial basis, therapy with LT4+LT3. Reducing the LT4 dose by 25 mcg/day and adding 2.5-7.5 mcg liothyronine (LT3) once or twice a day is an appropriate starting point. Transient episodes of hypertriiodothyroninemia with these doses of LT4 and LT3 are unlikely to go above the reference range and have not been associated with adverse drug reactions. Trials following almost a 1000 patients for almost 1 year indicate that similar to LT4, therapy with LT4+LT3 can restore euthyroidism while maintaining a normal serum TSH. An observational study of 400 patients with a mean follow-up of ∼9 years did not indicate increased mortality or morbidity risk due to cardiovascular disease, atrial fibrillation, or fractures after adjusting for age when compared with patients taking only LT4. Desiccated thyroid extract (DTE) is a form of combination therapy in which the LT4/LT3 ratio is ∼4:1; the mean daily dose of DTE needed to normalize serum TSH contains ∼11 mcg T3, but some patients may require higher doses. The DTE remains outside formal FDA oversight, and consistency of T4 and T3 contents is monitored by the manufacturers only. Conclusions: Newly diagnosed hypothyroid patients should be treated with LT4. A trial of combination therapy with LT4+LT3 can be considered for those patients who have unambiguously not benefited from LT4.

The association of serologically documented maternal thyroid conditions during pregnancy with bipolar disorder in offspring

OBJECTIVES

Higher rates of thyroid conditions are reported in individuals with bipolar disorder. However, no study to date has considered whether maternal thyroid conditions during pregnancy are associated with offspring risk of bipolar disorder, even though the fetus exclusively relies on maternal thyroid hormones through the early second trimester. We therefore examined the association between offspring bipolar disorder and serologically documented maternal thyroid conditions.

METHODS

The study was based on a nested case-control design that utilized data from the Child Health and Development Study, a birth cohort that enrolled pregnant women from 1959 to 1966. Eighty-five cases with DSM-IV-TR were ascertained and matched to controls (1:2) by date of birth, sex, gestational timing of the serum draws, and residence in Alameda County the first year receiving treatment. Archived prenatal maternal serum drawn during early to mid-gestation was used to measure two thyroid hormones, free thyroxine (fT4) and thyroid stimulating hormone (TSH). Subclinical and clinical hypothyroxinemia, hypothyroidism, and hyperthyroidism were determined based on standard methods.

RESULTS

Exposure to maternal hypothyroxinemia was associated with a five-fold increased risk of offspring bipolar disorder with psychotic features, but not without psychotic features. In stratified analysis, female offspring demonstrated increased risk for bipolar disorder with exposure to maternal hypothyroxinemia. No significant association was found between maternal hypothyroidism and offspring bipolar disorder.

CONCLUSIONS

These findings suggest that prenatal thyroid hormone deficiency, particularly a thyroid condition marked by low levels of thyroxine, may be an important developmental mechanism related to the risk of bipolar disorder with psychotic features.

Hormonal Treatments for Major Depressive Disorder: State of the Art

Major depressive disorder is a common psychiatric disorder associated with marked suffering, morbidity, mortality, and cost. The World Health Organization projects that by 2030, major depression will be the leading cause of disease burden worldwide. While numerous treatments for major depression exist, many patients do not respond adequately to traditional antidepressants. Thus, more effective treatments for major depression are needed, and targeting certain hormonal systems is a conceptually based approach that has shown promise in the treatment of this disorder. A number of hormones and hormone-manipulating compounds have been evaluated as monotherapies or adjunctive treatments for major depression, with therapeutic actions attributable not only to the modulation of endocrine systems in the periphery but also to the CNS effects of hormones on non-endocrine brain circuitry. The authors describe the physiology of the hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary thyroid (HPT), and hypothalamic-pituitary-gonadal (HPG) axes and review the evidence for selected hormone-based interventions for the treatment of depression in order to provide an update on the state of this field for clinicians and researchers. The review focuses on the HPA axis-based interventions of corticotropin-releasing factor antagonists and the glucocorticoid receptor antagonist mifepristone, the HPT axis-based treatments of thyroid hormones (T₃ and T₄), and the HPG axis-based treatments of estrogen replacement therapy, the progesterone derivative allopregnanolone, and testosterone. While some treatments have largely failed to translate from preclinical studies, others have shown promising initial results and represent active fields of study in the search for novel effective treatments for major depression.

The Treatment of Bipolar Depression: Current Status and Future Perspectives

Purpose of Review

This paper aims to review current available treatment options and to consider future directions in the treatment of bipolar depression.

Recent Findings

There are a limited number of established treatments that have demonstrated varied efficacy in acute bipolar depression including modern antipsychotics (quetiapine, lurasidone, olanzapine ± fluoxetine and recently cariprazine) and mood stabilisers (lamotrigine and valproate). Lithium has a role in protecting against depressive relapses and suicide. Alternative and experimental treatments including pramipexole, modafinil/armodafinil, omega-3 fatty acids and thyroxine may be used to augment the treatment of bipolar depression. Ketamine represents a major breakthrough, producing rapid reductions in depressive symptoms even in cases of treatment-resistance, but challenges remain in how best to maintain response and reduce unwanted side effects.

Summary

There remains uncertainty with regard to the relative efficacy and safety of established and experimental treatments for bipolar depression. Further work using consistent, optimal trial designs as well as further investigation into novel compounds and treatment interventions is warranted.

Treatment of bipolar depression with supraphysiologic doses of levothyroxine: a randomized, placebo-controlled study of comorbid anxiety symptoms

Background

Symptoms of anxiety co-occur in a variety of disorders including in depressive episodes of bipolar disorder and in patients with thyrotoxicosis. Treatment of refractory bipolar disorder with supraphysiologic doses of levothyroxine (L-T4) has been shown to improve the phenotypic expression of the disorder and is associated with an increase of circulating thyroid hormones. However, it might be associated with somatic and mental adverse effects. Here we report the investigation of the influence of treatment with supraphysiologic doses of L-T4 on symptoms of anxiety in patients with refractory bipolar depression.

Methods

Post-hoc analysis from a 6-week, multi-center, randomized, double-blind, placebo-controlled study of the effects of supraphysiologic L-T4 treatment on anxiety symptoms in bipolar depression. Anxiety symptoms were measured weekly with the Hamilton anxiety/somatization factor (HASF) score of the Hamilton Depression Rating Scale (HAMD) and the State- and Trait Anxiety Inventory (STAI).

Results

Treatment of both groups was associated with a significant reduction in anxiety symptoms (p < 0.001) with no statistical difference between groups (LT-4: from 5.9 (SD = 2.0) at baseline to 3.7 (SD = 2.4) at study end; placebo: from 6.1 (SD = 2.4) at baseline to 4.4 (SD = 2.8) at study end; p = 0.717). Severity of anxiety at baseline did not show a statistically significant correlation to the antidepressive effect of treatment with supraphysiologic doses of L-T4 (p = 0.811). Gender did not show an influence on the reduction of anxiety symptoms (females: from 5.6 (SD = 1.7) at baseline to 3.5 (SD = 2.4) at study end; males: from 6.1 (SD = 2.3) at baseline to 4.0 (SD = 2.4) at study end; p = 0.877).

Conclusions

This study failed to detect a difference in change of anxiety between bipolar depressed patients treated with supraphysiologic doses of L-T4 or placebo. Comorbid anxiety symptoms should not be considered a limitation for the administration of supraphysiologic doses of L-T4 refractory bipolar depressed patients.

Trial registration ClinicalTrials, ClinicalTrials.gov identifier: NCT01528839. Registered 2 June 2012—Retrospectively registered, https://clinicaltrials.gov/ct2/show/study/NCT01528839