Subclinical hypothyroidism resulting from autoimmune thyroiditis in female patients with endogenous depression

Clinical correlates of autoimmune thyroiditis and non-autoimmune hypothyroidism in treatment-naïve patients with major depressive disorders

BACKGROUND

Thyroid autoimmunity is a potentially critical factor that is often neglected in the association between subclinical hypothyroidism (SCH) and depressive disorders. This study aimed to investigate the clinical correlates of autoimmune thyroiditis (AIT) and non-autoimmune hypothyroidism (NAIH) in treatment-naïve patients with major depressive disorder (MDD).

METHOD

Using a cross-sectional design, we recruited a total of 1718 outpatients with treatment-naïve MDD. Demographic and relevant clinical information including duration of MDD, severity of depression and anxiety, psychotic symptoms, suicide attempts, thyroid function parameters, etc. were collected. According to thyroid function parameters, patients were classified as AIT, NAIH, latent Hashimoto's thyroiditis (LH) and euthyroidism (ET).

RESULTS

Patients with SCH (including AIT and NAIH) had older age at onset, and were more likely to have psychotic symptoms compared to those with ET. Multiple linear regression analysis showed that SCH was associated with duration of MDD and HAMD scores. Logistic regression analysis showed that the odds of having more severe anxiety and metabolic syndrome were greater among patients with SCH compared to those with ET. The odds of having suicide attempts were greater among patients with AIT than among those with ET.

LIMITATION

Because of the cross-sectional design of this study, we were unable to sort out causality between MDD and SCH.

CONCLUSION

Our findings suggested that AIT and NAIH were associated with duration of MDD, HAMD scores, severity of anxiety, and metabolic syndrome. However, only AIT in SCH was associated with suicide attempts.

Association between subclinical hypothyroidism and depression: an updated systematic review and meta-analysis

BACKGROUND

Although depression is associated with changes in the hypothalamic-pituitary-thyroid axis, its relationship with subclinical hypothyroidism (SCH) is controversial. To date, there is a lack of data on the improvement of depressive symptoms with levothyroxine therapy among individuals with coexistent SCH.

METHODS

We conducted a meta-analysis to evaluate the association between SCH and depression including 1) the prevalence of depression in SCH (with a sub-analysis of the geriatric cohort), 2) thyroid stimulating hormone (TSH) level among patients with depression and 3) the effect of levothyroxine therapy among patients with SCH and coexistent depression.

RESULTS

In a pooled analysis of 12,315 individuals, those with SCH had higher risk of depression than euthyroid controls (relative risk 2.35, 95% confidence intervals [CI], 1.84 to 3.02; p < 0.001). Geriatric cohort with SCH had a 1.7-fold higher risk of depression compared with healthy controls (odds ratio 1.72, CI, 1.10 to 2.70; p = 0.020). There was no difference in the mean TSH level between individuals with depression and healthy controls (2.30 ± 1.18 vs. 2.13 ± 0.72 mIU/L, p = 0.513). In individuals with SCH and coexistent depression, levothyroxine therapy was neither associated with improvement in the Beck Depression Inventory scoring (pooled d + = - 1.05, CI -2.72 to 0.61; p = 0.215) nor Hamilton Depression Rating Scale (pooled d + = - 2.38, CI -4.86 to 0.10; p = 0.060).

CONCLUSION

SCH has a negative impact on depression. Early and routine screening of depression is essential to prevent morbidity and mortality. However, the use of levothyroxine among patients with SCH and coexistent depression needs to be individualized.

Lithium and the thyroid

The common thyroid disorders are all autoimmune in origin, with the lifetime risk of thyroid disease being 1–2%. Thyroid autoantibodies are present in 9% of the adult population and 12.7% of women, with the frequency rising steeply in women over 45 years of age (Myers & West, 1987). In addition, 20% of the over 60–year-olds have an abnormal (raised) thyroid stimulating hormone (TSH). The presence of both raised TSH and thyroid autoantibodies is associated with the development of clinical hypothyroidism at the rate of 5% per year (Myers & West, 1987).

Increased aggression and lack of maternal behavior in Dio3-deficient mice are associated with abnormalities in oxytocin and vasopressin systems

Thyroid hormones regulate many aspects of brain development and function, and alterations in the levels of thyroid hormone action lead to abnormal anxiety- and depression-like behaviors. A complement of factors in the brain function independently of circulating levels of hormone to strictly controlled local thyroid hormone signaling. A critical factor is the type 3 deiodinase (DIO3), which is located in neurons and protects the brain from excessive thyroid hormone. Here, we examined whether a local increase in brain thyroid hormone action secondary to DIO3 deficiency is of consequence for social behaviors. Although we did not observe alterations in sociability, Dio3-/- mice of both sexes exhibited a significant increase in aggression-related behaviors and mild deficits in olfactory function. In addition, 85% of Dio3-/- dams manifested no pup-retrieval behavior and increased aggression toward the newborns. The abnormal social behaviors of Dio3-/- mice were associated with sexually dimorphic alterations in the physiology of oxytocin (OXT) and arginine vasopressin (AVP), 2 neuropeptides with important roles in determining social interactions. These alterations included low adult serum levels of OXT and AVP, and an abnormal expression of Oxt, Avp and their receptors in the neonatal and adult hypothalamus. Our results demonstrate that DIO3 is essential for normal aggression and maternal behaviors, and indicate that abnormal local regulation of thyroid hormone action in the brain may contribute to the social deficits associated with neurodevelopmental disorders.

Decreased anxiety- and depression-like behaviors and hyperactivity in a type 3 deiodinase-deficient mouse showing brain thyrotoxicosis and peripheral hypothyroidism

Hypo- and hyperthyroid states, as well as functional abnormalities in the hypothalamic-pituitary-thyroid axis have been associated with psychiatric conditions like anxiety and depression. However, the nature of this relationship is poorly understood since it is difficult to ascertain the thyroid status of the brain in humans. Data from animal models indicate that the brain exhibits efficient homeostatic mechanisms that maintain local levels of the active thyroid hormone, triiodothyronine (T3) within a narrow range. To better understand the consequences of peripheral and central thyroid status for mood-related behaviors, we used a mouse model of type 3 deiodinase (DIO3) deficiency (Dio3 -/- mouse). This enzyme inactivates thyroid hormone and is highly expressed in the adult central nervous system. Adult Dio3 -/- mice exhibit elevated levels of T3-dependent gene expression in the brain, despite peripheral hypothyroidism as indicated by low circulating levels of thyroxine and T3. Dio3 -/- mice of both sexes exhibit hyperactivity and significantly decreased anxiety-like behavior, as measured by longer time spent in the open arms of the elevated plus maze and in the light area of the light/dark box. During the tail suspension, they stayed immobile for a significantly shorter time than their wild-type littermates, suggesting decreased depression-like behavior. These results indicate that increased thyroid hormone in the brain, not necessarily in peripheral tissues, correlates with hyperactivity and with decreases in anxiety and depression-like behaviors. Our results also underscore the importance of DIO3 as a determinant of behavior by locally regulating the brain levels of thyroid hormone.

Bipolar disorder and antithyroid antibodies: review and case series

Mood disorders and circulating thyroid antibodies are very prevalent in the population and their concomitant occurrence may be due to chance. However, thyroid antibodies have been repeatedly hypothesized to play a role in specific forms of mood disorders. Potentially related forms include treatment-refractory cases, severe or atypical depression, and depression at specific phases of a woman’s life (early gestation, postpartum depression, perimenopausal). With regard to bipolar disorder, studies of specific subgroups (rapid cycling, mixed, or depressive bipolar) have reported associations with thyroid antibodies. Offspring of bipolar subjects were found more vulnerable to develop thyroid antibodies independently from the vulnerability to develop psychiatric disorders. A twin study suggested thyroid antibodies among possible endophenotypes for bipolar disorder. Severe encephalopathies have been reported in association with Hashimoto’s thyroiditis. Cases with pure psychiatric presentation are being reported, the antithyroid antibodies being probably markers of some other autoimmune disorders affecting the brain. Vasculitis resulting in abnormalities in cortical perfusion is one of the possible mechanisms.

The prevalence of depression and anxiety disorders in patients with euthyroid Hashimoto's thyroiditis: a comparative study

OBJECTIVE

The aim of this study was to examine the current prevalence of major depression and anxiety disorders in patients with euthyroid Hashimoto's thyroiditis (HT) and euthyroid goiter.

METHOD

The study sample was formed by consecutive 51 and 45 patients who were admitted to the endocrinology outpatient clinic and diagnosed with euthyroid HT and endemic/nonendemic goiter, respectively, and 68 healthy controls. Current diagnoses of psychiatric disorders were determined using the Structured Clinical Interview for DSM-IV. Beck Depression Inventory and Beck Anxiety Inventory were applied to the participants.

RESULTS

There was a statistically significant difference among the three groups in terms of major depression (P=.001), any mood or anxiety disorder (P=.000), any depressive disorder (P=.020), any anxiety disorder (P=.016) and obsessive-compulsive disorder (OCD) (P=.013). In the HT group, the prevalence of depression (P=.000), OCD (P=.005) and panic disorder (P=.041) was significantly higher than that in the control group. In the goiter group, depression (P=.006), any depressive disorder (P=.03), and any mood or anxiety disorder (P=.000) were significantly common in comparison to the control group. No significant difference was found between the HT and goiter groups.

CONCLUSIONS

Euthyroid HT and euthyroid goiter increase predisposition to major depression and anxiety disorders, and thyroid autoimmunity and other thyroid pathologies should be investigated in euthyroid patients with chronic and treatment-resistant complaints.

Peripheral thyroid dysfunction in depression

The involvement of the thyroid gland and thyroid hormones is generally believed to be important in the aetiopathogenesis of major depression. Major support comes from studies in which alterations in components of the hypothalamic-pituitary-thyroid (HPT) axis have been documented in patients with primary depression. However, screening thyroid tests are often routine and add little to the diagnostic evaluation. Overt thyroid disease is rare among depressed inpatients. The finding that depression often co-exists with autoimmune subclinical thyroiditis suggests that depression may cause alterations in the immune system, or that in fact it could be an autoimmune disorder itself. The outcome of treatment and the course of depression may be related to thyroid status as well. Augmentation of antidepressant therapy with the co-administration of thyroid hormones (mainly T3) is a well-documented treatment option for refractory depressed patients. Review of the literature suggests that there are no conclusive data on the role of thyroid function in depression. It is clear that depression is not characterised by an overt thyroid dysfunction, but it is also clear that a subgroup of depressed patients may manifest subtle thyroid abnormalities, or an activation of an autoimmune process. There is a strong possibility that the presence of a subtle thyroid dysfunction is a negative prognostic factor for depression and may demand specific therapeutic intervention.

Thyroid autoimmunity, depression and anxiety; are there any connections? An epidemiological study of a large population

OBJECTIVE

The aim of the study was to examine the relationship between antithyroid antibodies, depression, and anxiety in a large population.

METHODS

In a population of 30,175 individuals aged 40-84 years, thyroid-stimulating hormone (TSH) was assessed in all women and in 50% of the men. Thyroid peroxidase autoantibodies (TPOAb) were measured in almost all samples with TSH > or = 4.0 mU/L (n = 1700) and in randomly selected samples without thyroid disease or biochemical dysfunction (n = 745). The levels of anxiety and depression were screened using the Hospital Anxiety and Depression Scale (HADS). Relations were investigated with multiple logistic regression analyses.

RESULTS

In individuals with normal TSH and without known thyroid disorder, the prevalence of TPOAb was 14.2% in women and 4.3% in men. The prevalence of TPOAb in participants with biochemical thyroid dysfunction was 59.0% in women and 38.9% in men. No associations were found between thyroid autoimmunity and depression or anxiety, neither crude nor adjusted for age, gender, TSH, and thyroxine (T4).

CONCLUSION

Thyroid autoimmunity is a common disorder in the population, mainly affecting females. In a population-based study, no associations were found between antithyroid antibodies and depression or anxiety.

[Prevalence of thyroid disorders in patients diagnosed with depression]

OBJECTIVE

To determine the prevalence of thyroid disorders in patients diagnosed with depression.

DESIGN

Cross-sectional descriptive study (random sampling).

SETTING

Primary care, San Fernando (Cádiz).

PATIENTS

Patients diagnosed with depression (DSM IV criteria) at the San Fernando Mental Health Centre.

MEASUREMENTS AND MAIN RESULTS

108 patients were studied (95% CI; p = 11 +/- 5%), in whom figures for TSH in the blood, free T3 and T4 and anti-thyroid antibodies (anti-thyroglobulin and anti-TPO) were determined. We found a predominance of women among the patients studied (5:1) and only found thyroid disorders in women (100%). The age group with greatest frequency of depressive illness was from 50 to 59. 73.1% of all the thyroid disorders were found in the 30-59 age group. We detected a high number of depressive patients with unknown thyroid analytic disorder (24.1%) and a relevant prevalence of depressives with thyroid auto-immune disease (16.6%), especially due to positive anti-TPOs, exceeding the prevalence in previous studies. There was less hypothyroidism than expected (7.4% against 8-14%), although more than the estimated figure for the population as a whole (5%).

CONCLUSIONS

Indiscriminate thyroid tests on depressive patients, as a screening method, can be dispensed with. Given the results of anti-thyroid antibodies and the few studies of prevalence in the depressive population, it seems appropriate to conduct studies with a bigger sample and meta-analysis previous research.

Clinical manifestations of postpartum thyroid disease

Postpartum thyroiditis (PPT) occurs in 5%-9% of unselected postpartum women; hyperthyroidism and hypothyroidism develop, the latter being permanent, in up to 25 %-30% of women. PPT is strongly associated with antithyroid peroxidase (anti-TPO) antibodies, but 50% of anti-TPO positive women do not develop thyroid dysfunction. Symptom analysis has shown that lack of energy and irritability were the most frequent hyperthyroid symptoms whereas lack of energy, aches and pains, poor memory, dry skin, and cold intolerance were the significant hypothyroid features. Some of these symptoms were more frequently observed than in antibody-negative controls even when these patients were euthyroid and in anti-TPOAb positive women who did not develop PPT at all. The diagnosis of PPT is based on the observation of abnormal thyroid function tests in a postpartum anti-TPOAb-positive woman: transient hyperthyroidism occurs at 14 weeks and hypothyroidism at 19 weeks postpartum. Diffuse or multifocal hypoechogenicity of the thyroid is seen on echography and a thyroid destructive process is evidenced by an increase in serum thyroglobulin and urinary iodine excretion. In addition to the 25%-30% of women who develop permanent hypothyroidism at 3 years, recent data indicate that 50% of women who have developed PPT will be hypothyroid 7-9 years later. The long-term risk is only 5% for those anti-TPOAb positive women not developing thyroid dysfunction postpartum. The risk of recurrent PPT is 70% if previous PPT was experienced and 25% if the patient was euthyroid after the first pregnancy.

Certainty, leaps of faith, and tradition: rethinking clinical interventions

Clinical decision making requires that clinicians think quickly and in ways that will foster optimal, safe client care. Tradition influences clinical decision making, enhancing efficiency of resulting nursing action; however, since many decisions must be based on data that are either uncertain, incomplete, or indirect, clinicians are readily ensnared in processes involving potentially faulty logic associated with tradition. The author addresses the tenacity of tradition and then focuses on three processes--consensus formation, the grounding of certainty in inductive reasoning, and affirming the consequent--that have affected clinical decision making. For some recipients of care, tradition has had a substantial and invalid influence on their ability to access care.

The diagnosis and treatment of subclinical hypothyroid states in depressed patients

The diagnosis and treatment of subclinical hypothyroidism in mood-disordered patients is complex and somewhat controversial. The psychiatrist must recognize that such subclinical states may contribute to depression, mood cycling, or delayed response to treatment if undetected. Autoimmune thyroiditis, which may ultimately lead to various grades of hypothyroidism, may also be seen in depressed populations, particularly in postpartum females. The author discusses these issues by means of a clinical vignette, then proposes an algorithm for the diagnosis and treatment of hypothyroid states in mood disordered populations.

Psychopathological and cognitive features in subclinical hypothyroidism

1. To evaluate effective and cognitive dysfunctions in subjects with a marginal form of thyroid hypofunction the authors studied a population of female goiter patients, divided in two groups on the basis of thyroid function: euthyroidism and subclinical hypothyroidism (SCH). 2. The SCH patients were treated with levothyroxine (LT4) in order to obtain euthyroidism, as demonstrated by normalization of the hormonal pattern. 3. Both groups were evaluated with a wide range of psychometric tests (Wechsler memory test, scribble test, reaction times) and psychopathological rating scales (Hamilton rating scales for depression and anxiety, brief psychiatric rating scale) at admission and after 3 months. 4. At admission, a significant decrease in logical memory was found in SCH patients; no differences in affectivity ratings were found between the groups. 5. After LT4 treatment, SCH patients showed a significant improvement in some items of memory performance. 6. In conclusion, when interfering factors relating to the perception of disease were excluded by employing euthyroid goiter patients as a comparison group, SCH appeared associated only with memory impairment, while the impairment of affective functions described in previous studies comparing SCH patients with normal controls was not confirmed. A significant improvement of memory skills was induced by LT4 treatment in SCH patients.

Prospective study on thyroid autoimmunity and dysfunction related to chronic hepatitis C and interferon therapy

This study was designed to assess patients with chronic hepatitis C (CHC) for the presence of thyroid autoimmunity and dysfunction, to evaluate the risk of thyroid disorders associated with interferon (IFN) therapy, and to survey the outcome of possible treatment-related thyroid injury. Out of 104 consecutive untreated patients (30 women and 74 men; mean age, 52.7 years), 8 (7.7%) were found seropositive for thyroid autoantibodies (ThyAb), whereas seropositivity in healthy controls was 1/98 (1.3%). The relative increase in risk of developing thyroid autoimmunity associated with CHC was 760% (95% CI, 220-1300%). No patients had abnormalities of thyroid function tests, but on IFN treatment, 3/3 patients showed a rapid over-range rise in circulating thyrotropin, which returned to normal after therapy discontinuation. In the other 5 seropositive patients who refused treatment, thyroid function remained normal. Out of the 58 initially seronegative patients who consented to IFN treatment, 9 (15.5%) developed thyroid autoimmunity. Seven of them (77.7%) had thyroid dysfunction: hypothyroidism in 4 cases, transient thyrotoxicosis in 2 cases. The last patient developed TSH-receptor antibodies and Graves' disease, requiring methimazole therapy. Thyroid function recovered in the former 6 cases following IFN discontinuation. In the 28 initially seronegative patients who refused IFN and participated in a preliminary tauroursodeoxycholic acid trial, antithyroglobulin antibodies alone appeared in one case, but no thyroid dysfunction was observed. The relative risk of thyroid autoimmune disorder associated with IFN therapy was 342% (28-636%). The patients with CHC were unlikely to develop thyroid dysfunction in the absence of IFN therapy, in spite of being ThyAb seropositive. Moreover, a considerable proportion of seronegative patients, when IFN-treated, developed thyroid autoimmunity and then thyroid dysfunction. Both in seropositive and seronegative patients immediate IFN discontinuation normalized thyroid function and hormone replacement therapy was not necessary.

Pituitary responses to thyrotropin releasing hormone stimulation in depressed women with thyroid gland disorders

From an endocrine outpatient clinic and psychiatric outpatient clinic in Kaunas, Lithuania, 41 women with major depression were selected for study. Three groups of depressed women were established: 15 with autoimmune thyroiditis (AIT); 13 with diffuse non-toxic goiter (DNG); 13 with no thyroid disease (NTD). Standard biochemical tests were used to exclude patients with overt hypothyroidism or overt hyperthyroidism. At baseline the three groups were similar in age and almost identical in severity of depression. In part because of exclusion criteria, all baseline biochemical measures were similar. However, a slight elevation of thyroid-stimulating hormone (TSH) in the AIT group was noted and considered to indicate a tendency toward subclinical hypothyroidism. After thyrotropin-releasing hormone (TRH) administration, six AIT women and six DNG women, but no NTD women, showed blunted TSH responses. As a group DNG women showed smaller TRH responses than other women. Four AIT women showed exaggerated TSH responses. In all three groups basal TSH correlated positively with TSH response to TRH. Basal prolactin (PRL) responses to TRH infusion were similar in all three groups. However, the four AIT women with enhanced TSH responses also showed enhanced PRL responses. Indeed, in the AIT group, but only in this group, PRL responses were correlated with both TSH and basal TSH. In all groups of women the PRL response was unrelated to basal PRL.

Subclinical hypothyroidism does not lead to alterations either in peripheral nerves or in brainstem auditory evoked potentials (BAEPs)

Functional alterations in the central nervous system and peripheral nerves are well documented in overt hypothyroidism, but not in subclinical hypothyroidism. Twenty-seven patients with subclinical hypothyroidism were compared with a control group of 20 age- and sex-matched subjects to determine whether subclinical hypothyroidism can lead to alterations in peripheral nerves or in the brainstem auditory evoked potentials (BAEPs). None of the patients had carpal tunnel syndrome or any other neurological or metabolic disturbances. Disease duration (expressed as the time from diagnosis of subclinical hypothyroidism to the time of neurological testing) ranged from less than 1 month to 6 months (median 2.5 months). We studied the distal motor latency, nerve conduction velocity (NCV), compound muscle action potentials, and F response in the median and peroneal nerves whereas the sensory nerve conduction velocity and sensory potential amplitude were measured in the sural and median nerves. Electrophysiological parameters and interpeak latencies yielded no significant difference between patient and control groups. The present study indicates that subclinical hypothyroidism of short duration does not lead to abnormalities of peripheral nerves or brainstem auditory evoked potentials.