The thyroid and mixed affective states

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.

Reviewing the diagnostic validity and utility of mixed depression (depressive mixed states)

Objective

To review the diagnostic validity and utility of mixed depression, i.e. co-occurrence of depression and manic/hypomanic symptoms.

Methods

PubMed search of all English-language papers published between January 1966 and December 2006 using and cross-listing key words: bipolar disorder, mixed states, criteria, utility, validation, gender, temperament, depression-mixed states, mixed depression, depressive mixed state/s, dysphoric hypomania, mixed hypomania, mixed/dysphoric mania, agitated depression, anxiety disorders, neuroimaging, pathophysiology, and genetics. A manual review of paper reference lists was also conducted.

Results

By classic diagnostic validators, the diagnostic validity of categorically-defined mixed depression (i.e. at least 2–3 manic/hypomanic symptoms) is mainly supported by family history (the current strongest diagnostic validator). Its diagnostic utility is supported by treatment response (negative effects of antidepressants). A dimensionally-defined mixed depression is instead supported by a non-bi-modal distribution of its intradepression manic/hypomanic symptoms.

Discussion

Categorically-defined mixed depression may have some diagnostic validity (family history is the current strongest validator). Its diagnostic utility seems supported by treatment response.

The Neurobiology of Mixed States

Interest in the coexistence of manic and depressive symptoms fostered hypotheses on neurobiological underpinnings of mixed states. Neurobiological properties of mixed states, however, have not been comprehensively described. The authors searched databases for articles on neurobiological markers related to mixed states. Results showed that mixed states are characterized by elevated central and peripheral monoamine levels, greater alterations in hypothalamic-pituitary-adrenal axis, increased inflammation, and greater circadian rhythms dysfunction than nonmixed forms. Furthermore, the magnitude of pathophysiologic alterations in mixed states exceeds those associated with nonmixed mania or depression and suggest that hyperactivation and hyperarousal are core features of mixed states.

Sex difference in the progression of manic symptoms during acute hospitalization: A prospective pilot study

OBJECTIVES

Acute mania is a serious medical condition that impacts men and women equally. Longtime presentation of manic symptoms is sex-dependent; however, little is known about acute symptoms of mania. The objective of this study is to track and compare acute manic symptoms for sex differences during inpatient hospitalization.

METHODS

All patients with bipolar mania admitted to a large university hospital between January and October 2017 were invited to participate in this longitudinal naturalistic follow-up study. Manic (YMRS), depressive (MADRS), and psychotic (PAS) symptoms were tracked daily from admission to discharge.

RESULTS

The total YMRS scores decreased significantly overtime (p < .0001) in both male (n = 34) and female (n = 23) patients (p = .7). However, male patients scored significantly higher in sexual interest (p = .01), disruptive and aggressive behavior (p = .01), and appearance (p < .001) while females had better insight into their illness (p = .01). Males and females received similar doses of lithium (p = .1), but males received significantly higher doses of valproic acid (VPA) in comparison with females (p = .003). However, plasma lithium and VPA concentrations at discharge were not significantly different between sexes.

CONCLUSION

Our results show sex differences in the progression of certain domains of manic symptoms in a cohort of 23 female and 34 male patients admitted to a large academic center in Turkey. Males, in this sample, exhibited more sexual interest, disruptive and aggressive behaviors, better grooming, and less insight compared to females. While these results are concordant with our preclinical findings and with anecdotal clinical observations, replication in larger samples is needed.

Rapid cycling bipolar disorder is associated with antithyroid antibodies, instead of thyroid dysfunction

BACKGROUND

Conclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting. Previous studies suggest that the impact of antithyroid antibodies on mental wellbeing seems to be independent of thyroid function. Here, we investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD).

METHODS

Fast serum levels of free thyroxine (FT4), free triiodothyronine (FT3), thyroid Stimulating Hormone (TSH), TPO-abs and Tg-abs were simultaneously measured in 352 patients with BD. Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education.

RESULTS

Neither hypothyroidism nor hyperthyroidism was significantly associated with RCBD. Both TPO-abs and Tg-abs were significantly related to RCBD, even after controlling for gender, age, marriage status, education, antidepressants treatment, comorbidity of thyroid diseases, and thyroid function (serum levels of FT3, FT4 and TSH). Although TPO-abs and Tg-abs were highly correlated with each other, binary logistic regression with forward LR selected TPO-abs, instead of Tg-abs, to be associated with RCBD. TPO-abs was significantly, independently of Tg-abs, associated with hyperthyroidism, while Tg-abs was marginally significantly related to hypothyroidism at the presence of TPO-abs.

CONCLUSION

TPO-abs might be treated as a biomarker of RCBD. Further exploring the underlying mechanism might help understand the nature of RCBD and find out new treatment target for it.

Thyroid functioning in patients with bipolar disorder with mixed features

We compared the prevalence of thyroid dysfunction in patients with bipolar disorder with and without mixed features by measuring of thyroid function test. We reviewed the medical charts between 2005 and 2013. These results did not show a significant difference in the association between thyroid dysfunction and the mixed features.

Thyroid functions and bipolar affective disorder

Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT) axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition.

Pure and mixed manic subtypes: a review of diagnostic classification and validation

OBJECTIVE

To review issues surrounding the diagnosis and validity of bipolar manic states.

METHODS

Studies of the manic syndrome and its diagnostic subtypes were reviewed emphasizing historical development, conceptualizations, formal diagnostic proposals, and validation.

RESULTS

Definitions delineating mixed and pure manic states derive some validity from external measures. DSM-IV and ICD-10 diagnosis of bipolar mixed states are too rigid and less restrictive definitions can be validated. Anxiety is a symptom often overlooked in diagnosis of manic subtypes and may be relevant to the mixed manic state. The boundary for separation of mixed mania and depression remains unclear. A 'pure' non-psychotic manic state similar to Kraepelin's 'hypomania' has been observed in several independent studies.

CONCLUSIONS

Issues surrounding diagnostic subtyping of manic states remain complex and the debates surrounding categorical versus dimensional approaches continue. To the extent that categorical approaches for mixed mania diagnosis are adopted, both DSM-IV and ICD-10 are too rigid. Inclusion of non-specific symptoms in definitions of mixed mania, such as psychomotor agitation, does not facilitate and may hinder the diagnostic separation of pure and mixed mania. The inclusion of a diagnostic seasonal specifier for DSM-IV, which is currently based on seasonal patterns for depression might be expanded to include seasonal patterns for mania. Boundaries between subtypes may be 'fuzzy' rather than crisp, and graded approaches could be considered. With the continued development of new tools, such as imaging and genetics, alternative approaches to diagnosis other than the purely symptom-centric paradigms might be considered.

Gender differences in bipolar disorder

The presentation and course of bipolar disorder differs between women and men. The onset of bipolar disorder tends to occur later in women than men, and women more often have a seasonal pattern of the mood disturbance. Women experience depressive episodes, mixed mania, and rapid cycling more often than men. Bipolar II disorder, which is predominated by depressive episodes, also appears to be more common in women than men. Comorbidity of medical and psychiatric disorders is more common in women than men and adversely affects recovery from bipolar disorder more often in women. Comorbidity, particularly thyroid disease, migraine, obesity, and anxiety disorders occur more frequently in women than men, whereas substance use disorders are more common in men. Although the course and clinical features of bipolar disorder differ between women and men, there is no evidence that gender affects treatment response to mood stabilizers. However, women may be more susceptible to delayed diagnosis and treatment. Treatment of women during pregnancy and lactation is challenging because available mood stabilizers pose potential risks to the developing fetus and infant. Pregnancy neither protects nor exacerbates bipolar disorder, and many women require continuation of medication during the pregnancy. The postpartum period is a time of high risk for onset and recurrence of bipolar disorder in women, and prophylaxis with mood stabilizers might be needed. Individualized risk/benefit assessments of pregnant and postpartum women with bipolar disorder are required to promote the health of the woman and avoid or limit exposure of the fetus or infant to potential adverse effects of medication.

Thyroid function in mixed and pure manic episodes

OBJECTIVES

Associations of both overt thyroid disease as well as subclinical thyroid abnormalities with affective disorders have been well established. Similar associations have been reported with mixed mania and rapid cycling bipolar disorder. We tested for differences in overt and subclinical thyroid disease and subclinical differences in a large series of bipolar patients examined during mixed or pure manic episodes.

METHODS

Rates of previously diagnosed thyroid disease were compared by sex, race and manic subtype (mixed versus pure) in 443 patients. Serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) concentrations obtained from patients with no clinical thyroid disease collected during manic and mixed bipolar episodes were compared using ANOVA statistics. Race was also included in the model and age was covaried.

RESULTS

Rates of thyroid disease, in particular hypothyroidism, were higher in females and white people, and increased with advancing age. No differences were noted between subjects sampled during mixed or pure manic episodes. In patients with no history of thyroid disease, serum TSH and FT4 concentrations did not differ between manic subtypes or between sexes. TSH levels however, were significantly lower in African Americans.

CONCLUSIONS

We did not confirm past reports of associations of overt or subclinical thyroid disease with mixed manic episodes. African Americans had significantly lower serum TSH concentrations than white people, while FT4 levels did not differ.

The role of gender in mixed mania

This article reviews the literature regarding possible gender differences in adults with mixed mania. Studies examining gender differences in the prevalence of mixed mania, biological abnormalities, suicidality, long-term outcome, and treatment response were analyzed. Data from these studies suggest that mixed mania may occur more commonly in women than in men, especially when defined by narrow criteria. There were no significant differences between men and women with mixed mania in biological abnormalities, suicidality, outcome, and treatment response.

Psychoneuroendocrinology of mood disorders. The hypothalamic-pituitary-thyroid axis

Abnormal thyroid functioning can affect mood and influence the course of unipolar and bipolar disorder. Even mild thyroid dysfunction has been associated with changes in mood and cognitive functioning. Thyroid hormone supplementation may have role in the treatment of certain mood disorders, particularly rapid-cycling bipolar disorder. Women are more vulnerable to thyroid dysfunction than men and also respond better to thyroid augmentation. This article reviews the relationship between thyroid function and mood, and the use of thyroid hormones in the treatment of mood disorders. The impact of gender on these issues is also discussed.

Differences in thyroid function between bipolar manic and mixed states

BACKGROUND

High rates of thyroid axis abnormalities have been reported in most studies of patients with rapid-cycling bipolar disorder. Mixed states share similarities with rapid-cycling, including close temporal occurrence of manic and depressive symptoms, predominance in women, poor outcome, and less robust response to lithium compared with pure mania; however, thyroid axis abnormalities have not been well studied in mixed mania.

METHODS

To test the hypothesis that mixed states are associated with a higher prevalence of hypothyroidism than pure mania, immunoreactive triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) concentrations were determined from serum obtained at the time of admission in 37 consecutive patients with DSM-III-R bipolar disorder, manic or mixed.

RESULTS

The mean TSH concentration was significantly higher, and the mean T4 concentration was significantly lower in patients with mixed mania compared with pure mania. There were no significant differences in T3 concentration or in previous lithium exposure.

CONCLUSIONS

These findings suggest thyroid axis dysfunction is more common in bipolar mixed than in bipolar manic patients.