Relationship between psychotropic drugs and thyroid function: a review

Hypothyroidism in a Psychiatric Outpatient Population of People With Intellectual Disabilities

INTRODUCTION

Hypothyroidism is a chronic health condition which causes physical, cognitive and psychiatric symptoms. The prevalence of hypothyroidism in adults with intellectual disabilities is under researched.

METHOD

Hypothyroidism was examined among 463 patients within an outpatient intellectual disability psychiatric team. Clinic records were utilised for this study, including sociodemographic, psychiatric and physical health diagnoses.

RESULTS

Among the 463 patients, 43 (9%) had hypothyroidism. Compared to those without hypothyroidism, the hypothyroid group were significantly older, more likely to be female, and had increased rates of high cholesterol, diabetes, Down's Syndrome and dementia.

DISCUSSION

Rates of hypothyroidism within this cohort of patients with intellectual disabilities were high (9%). The results suggest hypothyroidism in intellectual disability should be the focus of prospective research, in larger, more representative samples. This study indicates a need for increased awareness of, and resources for hypothyroidism in health services.

Isolated central hypothyroidism: Underlying pathophysiology and relation to antidepressant and antipsychotic medications-A multi-centre South Wales study

OBJECTIVE

Isolated biochemical central hypothyroidism is a presentation we are experiencing more frequently as endocrinologists, with variation in levels of investigation between physicians. We therefore conducted research to investigate the final diagnosis and clinical outcome of patients across multiple hospitals in South Wales with biochemical isolated central hypothyroidism; namely to establish whether this isolated biochemical picture was clinically significant. We also analysed whether there is an association between this biochemical picture and treatment with antidepressant and antipsychotic medications, and how common this is.

DESIGN

We performed a retrospective observational study of patients across nine different hospitals in South Wales. We analysed patients referred to endocrinology at each site over a 6-year period with unexplained isolated biochemical central hypothyroidism.

MATERIALS AND METHODOLOGY

1022 individual patients' thyroid function test results were identified from our biochemical database using our inclusion criteria. After exclusion criteria were applied, 71 patients' results were analysed as to the final pathophysiology of their central hypothyroidism.

RESULT

Of the 71 patients included in the study, none were found to have any clinically significant pathology on pituitary imaging. On reviewing their medications, 46/71 (65%) were found to be taking psychotropic medications.

CONCLUSIONS

Our study strongly suggests isolated central hypothyroidism, in the absence of other pituitary hormone dysfunction or visual field defect, does not require further investigation, saving resources as well as sparing patients unnecessary anxiety. It also strongly supports a relationship between patients taking psychotropic medications and biochemical isolated central hypothyroidism, an association only described in a very limited amount of literature before this, and further supporting our previous single-centre study findings. The mechanism behind this is likely to be the suppression of thyrotropin secretion via antagonism of the dopamine-serotoninergic pathway. In our opinion, patients found to have isolated biochemical central hypothyroidism who are taking psychotropic medications can therefore be regarded to have a recognised cause for this biochemical finding and do not require further radiological investigation.

Influence of medications on thyroid function in dogs: An update

Erroneous thyroid function test results can occur because of drugs that alter thyroid hormone physiology in one or more aspects, including synthesis, secretion, distribution, and metabolism. Research since publication of the last review in the Journal of Veterinary Internal Medicine (JVIM) 20 years ago has evaluated the effects of amiodarone, zonisamide, inhalant anesthetics, clomipramine, trilostane, and toceranib on thyroid function tests in the dog. In addition, recent work on the effects of glucocorticoids, sulfonamides, phenobarbital, and nonsteroidal anti-inflammatory drugs will be reviewed. Awareness of these effects is necessary to avoid misdiagnosis of hypothyroidism and unnecessary treatment.

Central hypothyroidism related to antipsychotic and antidepressant medications: an observational study and literature review

OBJECTIVE

To investigate the final diagnosis and clinical outcome of patients referred to endocrinology in our district general hospital with biochemical isolated central hypothyroidism (CeH), and whether there is an association between this biochemical picture and treatment with antidepressant and antipsychotic medications.

METHODS

We performed a retrospective observational study of patients referred to endocrinology with unexplained biochemical isolated CeH over a 5-year period.

RESULTS

Of the 29 patients included in the study, 4 were found to have a partially empty or empty sella and 1 to have a bulky pituitary gland which was deemed to be an incidental radiological finding. No patients had any clinically significant pathology. On reviewing their medications, 18/29 (62%) were found to be on psychotropic medications.

CONCLUSIONS

Our study suggests a relationship between patients on psychotropic medications and biochemical isolated CeH, an association only described in a very limited amount of literature prior to this. The mechanism behind this may be suppression of TSH secretion via antagonism of the dopamine-serotoninergic pathway. Determining a correlation between psychotropic medications and isolated CeH could lead to the avoidance of further radiological investigations and unnecessary anxiety for patients. However, a larger observational study is needed to provide further evidence to support/refute our finding.

Pathophysiology and Clinical Features of Neuropsychiatric Manifestations of Thyroid Disease

Thyroid hormones (TH) have a cardinal role in the development of the central nervous system during embryogenesis and early infancy. However, the TH-responsive genes in the developing brain cease to respond to TH in adulthood. Nevertheless, thyroid dysfunction in adults is commonly associated with a host of cognitive and psychiatric problems. Cognitive decline, dysphoria, and depression are common manifestations of overt hypothyroidism while hyperthyroidism can cause agitation, acute psychosis, and apathy, especially in older people. Whereas levothyroxine treatment can reverse dementia in the setting of hypothyroidism, the effect of levothyroxine on depressive symptoms in subjects with subclinical hypothyroidism is controversial. The use of supraphysiologic doses of TH to treat depression refractory to antidepressant remains a viable therapeutic tool with the caveat that excessive doses of thyroid hormone to treat depression may have potentially damaging effects on other organ systems. The present communication describes the pathophysiology of neuropsychiatric manifestations of thyroid disease, including changes in neurotransmission, alterations in neuronal or glial cell gene expression, blood-brain barrier dysfunction, increased risk of cerebrovascular disease, and occasionally cerebral inflammatory disease in the context of autoimmune thyroid disease. Elucidating the molecular mechanisms of TH effect on cerebral tissue will help identify novel therapeutic targets for managing people with neuropsychiatric disorders.

Subclinical thyroid dysfunction and major depressive disorder

PURPOSE

This review attempts to investigate the link between subclinical thyroid dysfunction (SCH) and major depressive disorder (MDD). It has been speculated that SCH may be related to MDD through an autoimmune mechanism.

METHODS

A comprehensive literature search was conducted in the PubMed database for relevant research and review articles.

RESULTS

There appears to be an association between an autoimmune mechanism, possibly involving the thyroid gland, and depressive disorders, but the available evidence is so far inconclusive.

CONCLUSION

Lifetime prevalence of depression is significantly higher in patients with SCH, a finding reflecting a possible effect of SCH in lowering the threshold for the emergence of MDD. The relationship between SCH and MDD is, however, not clear, with large and well-designed studies investigating possible links between reference-range thyroid hormone levels and MDD having as yet found no relation between the two.

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 in Adults with Prader-Willi Syndrome; a Cohort Study and Literature Review

Prader–Willi syndrome (PWS) is a complex genetic syndrome combining hypotonia, hyperphagia, a PWS-specific neurocognitive phenotype, and pituitary hormone deficiencies, including hypothyroidism. The low muscle mass associated with PWS causes a low energy expenditure due to a low basal metabolic rate. Combined with increased energy intake due to hyperphagia, this results in a high risk of obesity and associated cardiovascular disease. To reduce the high mortality in PWS (3% yearly), exercise is extremely important. As hypothyroidism can impair exercise tolerance, early detection is crucial. We performed a literature search for articles on hypothyroidism in PWS, measured thyroid hormone (TH) levels in 122 adults with PWS, and performed a medical file search for medication use. Hypothyroidism (low free thyroxin) was present in 17%, and often central in origin (80%). Triiodothyronine levels were lower in patients who used psychotropic drugs, while other TH levels were similar. One in six patients in our cohort of adults with PWS had hypothyroidism, which is more than in non-PWS adults (3%). We recommend yearly screening of free thyroxin and thyroid-stimulating hormone levels to avoid the negative effects of untreated hypothyroidism on basal metabolic rate, body mass index, and cardiovascular risk. Additionally, we recommend measuring TH concentrations 3–4 months after the start of growth hormone treatment.

Anti-hyperprolactinemic activities of aqueous extract of Uvaria chamae (P. Beauv) roots and associated biochemical changes in chlorpromazine-induced hyperprolactinemic female Wistar rats

ETHNOPHARAMCOLOGICAL RELEVANCE

The age-long folkloric use of Uvaria chamae roots in the management of nipple discharge that is not related to pregnancy, childbirth or nursing but as a result of excessive production of prolactin (hyperprolactinemia) is yet to be substantiated with scientific data.

AIM OF THE STUDY

This study investigated the anti-hyperprolactinemic activities of aqueous extract of Uvaria chamae roots (AEUCR) and associated biochemical changes in chlorpromazine (CPZ)-induced hyperprolactinemic female Wistar rats.

MATERIALS AND METHODS

A total of sixty female rats (207.40 ± 2.69 g) were assigned into 6 groups: A-F. Animals in Group A received 0.5 ml of distilled water only whilst the 7 days CPZ-treated female rats (to induce hyperprolactinemia) in groups B, C, D, E, and F also received distilled water, 2.5 mg/kg body weight of bromocriptine (reference drug), 0.71, 1.41 2.83 mg/kg body weight of AEUCR for 28 days.

RESULTS

AEUCR contained a total of 15 (75%) amino acids with seven (46.67%) being essential amino acids and eight (53.33%) as non-essential amino acids. Administration of CPZ increased (p < 0.05) the levels of prolactin and testosterone, and reduced (p < 0.05) the levels of estradiol, progesterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), dopamine, triiodothyronine (T3) and tetraiodothyroxine (T4). Chlorpromazine also increased the levels of serum urea, creatinine, total protein, albumin, globulin, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) of the animals. In contrast, AEUCR significantly (p < 0.05) reduced the CPZ-induced increases in the levels of prolactin and testosterone, and increased the levels of CPZ-induced reduction in the progesterone, estradiol, FSH, LH, dopamine, T3 and T4. The AEUCR also reversed (p < 0.05) the CPZ-induced related increases in the levels of urea, creatinine, total protein, albumin, globulin, bilirubin, ALT, AST and ALP similar to the trends in the distilled water- and bromocriptine-treated controls. The CPZ-induced remarkable increase in the size of lactating alveolus and lactiferous duct distribution in the mammary gland were restored to normal tubule-alveolar female pattern mammary glands, composed of branching ducts and small alveoli budding off the ducts.

CONCLUSION

The study concluded that aqueous extract of Uvaria chamae root exhibited anti-hyperprolactinemic activity by restoring prolactin and dopamine levels and tubule-alveolar female pattern in female rats. It also ameliorated CPZ-induced changes in the liver and kidney function indices. This study justifies the folkloric use of Uvaria chamae root in the management of abnormal discharge by the nipples that is unrelated to pregnancy, childbirth and nursing.

Taurine and coenzyme Q10 synergistically prevent and reverse chlorpromazine-induced psycho-neuroendocrine changes and cataleptic behavior in rats

Over the years, mounting evidences have suggested a strong association between chronic chlorpromazine therapy, a popular first-generation antipsychotic drug, and psycho-neuroendocrine changes. In this study, we aim to examine whether treatment with taurine and coenzyme Q10 (COQ-10), compounds with steroidogenic-gonadotropin hormone-enhancing properties, can attenuate the negative impacts of chlorpromazine on steroidogenic, gonadotropin, thyroid and HPA-axis hormones, dopamine levels, catalepsy behavior and neuronal cells of the hypothalamus and pituitary gland in the preventive and reversal treatments in male Wister rats. In the drug treatment alone or preventive protocol, rats received oral administration of saline (10 mL/kg), taurine (150 mg/kg/day), COQ-10 (10 mg/kg/day), or both (taurine + COQ-10/day) alone for 56 consecutive days, or in combination with oral chlorpromazine (30 mg/kg/day) treatment from days 29 to 56. In the reversal protocol, the animals received chlorpromazine or saline for 56 days prior to taurine, COQ-10, or the combination from days 29 to 56. Thereafter, serum prolactin, steroidogenic (testosterone, estrogen, progesterone), gonadotropin (luteinizing hormone, LH, follicle-stimulating hormone, FSH), thyroid (thyrotropin-stimulating hormone, tetraiodothyronine, triiodothyronine) hormones, corticosterone, brain dopamine levels and cataleptic behavior were investigated. The histopathological features of the hypothalamus and pituitary gland were also evaluated. Taurine, COQ-10, or their combination prevented and reversed chlorpromazine-induced hyperprolactinemia, decrease in FSH, LH, testosterone, progesterone and dopamine concentrations, as well as the increase in estrogen levels. Taurine and COQ-10 reduced the changes in thyroid hormones, corticosterone release, histological distortions of the hypothalamus and the pituitary gland of chlorpromazine-treated rats. Taurine and COQ-10 attenuated chlorpromazine-induced catalepsy. The study showed that taurine and COQ-10 prevented and reversed chlorpromazine-induced changes in reproductive, thyroid hormones, dopamine level, corticosterone release, neurodegenerations, and cataleptic behavior in rats.

Clinical and laboratory aspects of 3,3',5'-triiodothyronine (reverse T3)

Reverse T3 (3,3',5'-triiodothyronine or rT3) is the third most abundant iodothyronine circulating in human blood and is produced by the inner ring deiodination of the pro-hormone thyroxine (T4). Unlike the more abundant and active metabolite T3, the measurement of serum rT3 is yet to find a routine clinical application. As rT3 binds weakly to the T3 thyroid nuclear hormone receptors, it is thought to represent an inactive end-product of thyroid hormone metabolism, diverting T4 away from T3 production. The analysis of serum rT3 has, up until recently, been measured by competitive radioimmunoassay, but these methods have been superseded by mass-spectrometric methods which are less susceptible to interference from other more abundant iodothyronines. Serum rT3 concentration is increased as part of the non-thyroidal illness syndrome, and by administration of common medications such as amiodarone which inhibit the metabolism of rT3. Serum rT3 concentration is also affected by genetic conditions that affect the iodothyronine deiodinases, as well as thyroid transporters and transport proteins. Analysis of rT3 can provide a useful diagnostic fingerprint for these conditions. rT3 has been shown to bind extra-nuclear iodothyronine receptors with a potential role in cell proliferation; however, the clinical relevance of these findings awaits further study.

Effects of treatment with haloperidol and clozapine on the plasma concentrations of thyroid hormones in rats

OBJECTIVES

Psychoactive drugs are group of compounds used to treat severe mental problems, including psychosis, as well as other conditions. This study assessed clinically relevant side effects of haloperidol and clozapine on the thyroid hormones.

METHODS

Haloperidol (0.05 and 2 mg/kg) or clozapine (0.5 and 20 mg/kg) was intraperitoneally injected to male Wistar rats for 28 days. The control group received 2 ml of physiological saline. A chemiluminescent immunoassay was used to measure the plasma levels of thyroid hormones.

RESULTS

Plasma concentrations of thyroxine (T4) in rats treated with high-dose (2 mg/kg) of haloperidol decreased significantly compared to the control group (p=0.001). However, both low (0.5 mg/kg) and high clozapine (20 mg/kg) doses did not have a significant effect on the plasma concentrations of T4 and triiodothyronine (T3) (p>0.05). Neither of the compound had a significant effect on T3 plasma concentration levels (p>0.05).

CONCLUSIONS

Haloperidol and clozapine act via different mechanisms and may have dissociable effects on thyroid hormones. Following treatment with haloperidol, significant changes in T4, but not in T3, serum levels were observed. Haloperidol and clozapine had different effects on the thyroid hormone levels. These results indicate that antipsychotic treatment can contribute to the thyroid dysfunction. Therefore, greater caution should be applied to the antipsychotics use. The thyroid function of the patients should be closely monitored, while using these drugs.

A rare cause of subclinical hypothyroidism: macro-thyroid-stimulating hormone

Background Subclinical hypothyroidism is a situation in which the thyroid-stimulating hormone (TSH) value exceeds the upper limit of normal, but the free triiodothyronine (T3) and thyroxine (T4) values are within the normal range. The etiology is similar to overt hypothyroidism. Case presentation An 18-year-old female patient was referred to our endocrinology clinic due to elevated TSH levels detected during a routine examination. She was clinically euthyroid and had a normal thyroid ultrasound pattern. The TSH concentration was measured twice independently, giving values of 5.65 μIU/mL and 5.47 μIU/mL. The polyethylene glycol (PEG) method for TSH measurement was used to determine the concentration of macro-TSH (m-TSH), a macromolecule formed between TSH and immunoglobulin (Ig). Using the same blood samples for which the TSH levels were found to be high, the PEG method found TSH levels to be within a normal range, with values of 1.50 μIU/mL (5.65-1.50 μIU/mL measured; a decrease of 75%) and 1.26 μIU/mL (5.47-1.26 μIU/mL measured; a decrease of 77%), respectively. The TSH values determined by the PEG precipitation test were markedly low, with PEG-precipitable TSH ratios greater than 75%. Conclusions The cause of 55% of subclinical hypothyroidism is chronic autoimmune thyroiditis. However, it is necessary to exclude other TSH-elevated conditions for diagnosis. One of these conditions is m-TSH, which should be kept in mind even though it is rarely seen. m-TSH should be considered especially in patients who have a TSH value above 10 μIU/mL without hypothyroidism symptoms or who require a higher levothyroxine replacement dose than expected to make them euthyroid.

Mental Health Conditions and Hyperthyroidism

OBJECTIVES

To evaluate the proportion of pediatric patients with concurrent diagnoses of hyperthyroidism and mental health conditions (MHCs) by using the Military Health System database. We hypothesized that the prevalence of mental health disorders would be higher in patients with hyperthyroidism compared with in the nonhyperthyroid population.

METHODS

The prevalence of hyperthyroidism and MHCs was calculated by using data extracted from the Military Health System Data Repository on military beneficiaries between 10 and 18 years old who were eligible to receive care for at least 1 month during fiscal years 2008 through 2016. Prevalence ratios were used to compare MHC diagnoses in those with versus without a diagnosis of hyperthyroidism.

RESULTS

There were 1894 female patients and 585 male patients diagnosed with hyperthyroidism during the study period. Prevalence ratios for MHCs in those with versus without hyperthyroidism ranged from 1.7 (attention-deficit/hyperactivity disorder [ADHD]) to 4.9 (bipolar disorder). Strikingly, suicidality was nearly 5 times more likely in patients diagnosed with hyperthyroidism than in patients who were never diagnosed with hyperthyroidism. For each of the MHCs examined, with the exception of suicidality, the MHC diagnosis was more commonly made before the diagnosis of hyperthyroidism, with the highest proportion of patients being diagnosed with ADHD before receiving a diagnosis of hyperthyroidism (68.3%).

CONCLUSIONS

There is a clear association between hyperthyroidism and each of the following MHCs: ADHD, adjustment disorder, anxiety, bipolar disorder, depression, and suicidality. This study highlights the need to consider this association when evaluating patients with overlapping symptoms and for effective mental health screening tools and resources for clinicians.

Free thyroxine and thyroid-stimulating hormone in severe mental disorders: A naturalistic study with focus on antipsychotic medication

BACKGROUND

Disturbances in thyroid function have been associated with use of psychotropic drugs, including antipsychotics. Still, the thyroid function in relation to commonly prescribed antipsychotic drugs and polypharmacy is not fully known. We investigated thyroid function associated with use of antipsychotics in patients with psychotic disorders compared with healthy controls.

METHODS

We included 1345 patients and 989 healthy controls from the Thematically Organized Psychosis (TOP) study, recruiting participants between 18 and 65 years of age in the Oslo-area. All patients underwent a thorough clinical investigation and assessment of medication data. Thyroid function was determined from plasma levels of free thyroxin (fT4) and thyroid-stimulating hormone (TSH). Multiple linear regression analyses were performed to evaluate the association between thyroid parameters and use of antipsychotics, and monotherapy users of olanzapine, quetiapine, aripiprazole or risperidone (N = 473) were investigated separately.

RESULTS

We found lower levels of fT4 (median 13.70 vs 14.00, p < 0.001) in patients compared to healthy controls, and a prevalence of 12.9% of previously undiagnosed deviant thyroid states in the patient group. Lower fT4 levels was associated with use of antipsychotics in general (p = 0.001), and quetiapine (p = 0.003) and olanzapine (p = 0.018) in particular, while the associations with TSH were non-significant. Using antipsychotics in combination with other psychotropic drugs, and with antidepressants in particular, was associated with lower fT4 level (p < 0.001) than use of antipsychotics alone.

CONCLUSIONS

Our findings indicate an association between use of antipsychotics and lower fT4. Clinicians should be aware that patients using quetiapine, olanzapine or antipsychotics in psychotropic polypharmacy are especially at risk.

FT4 and TSH, relation to diagnoses in an unselected psychiatric acute-ward population, and change during acute psychiatric admission

BACKGROUND

Alteration in thyroid activity is a well-known cause of symptoms mimicking psychiatric disorders. There are reports on altered levels of thyroid hormones in patients with certain psychiatric disorders compared to healthy controls; still, the magnitude and importance of the phenomenon is not known. We wanted to explore the level of thyroid hormones in different diagnostic groups in an acute-psychiatric population. We also wanted to follow any change during their stay.

METHODS

Patients aged 18 years and older admitted to a closed, psychiatric inpatient ward were eligible if giving informed consent. For 539 patients representing all main psychiatric diagnostic groups and with equal gender distribution, data for FT4 were available for 539 patients, and data for TSH were available from 538 patients at admittance. For 239 patients, data for FT4 were available at both admittance and discharge, and the corresponding number for TSH was 236 patients.

RESULTS

A significantly higher share of patients had higher levels of FT4 and TSH at admittance than expected for healthy individuals. No significant effect of gender or most diagnostic groups was seen. For female patients with substance-use disorder (SUD), the level of TSH was significantly lower than that for all other diagnostic groups. No other difference in the levels of FT4 and TSH was seen between the main diagnostic groups, and the effect in SUD was not seen in males. For the population with available markers at both admittance and discharge, in total, there was a significant reduction of FT4 from admittance to discharge, not followed by any change in TSH.

CONCLUSIONS

In acutely admitted psychiatric patients there seems to be an increased FT4 and TSH. FT4 is normalized during the inpatient stay independently of TSH. This indicates somatic effects of psychiatric stress that may be of clinical importance and the phenomenon should be further explored. Mainly different diagnostic groups did not differ in level of FT4 and TSH. Thus future studies on thyroid activity in psychiatric patients should focus on function and level of stress and suffering rather than diagnostic groups.

Effects of alprazolam and haloperidol on thyroglobulin, antithyroglobulin, anti thyroid peroxidase and TSH in Rat

Background:

A large number of psychotropic drugs can interfere with the thyroid physiology, function and autoimmunity.

Objective:

The aim of the present study was to investigate the effects of alprazolam and haloperidol on thyroglobulin, antithyroglobulin (aTg), antithyroid peroxidase, and thyroid stimulating hormone levels on rats.

Materials and Methods:

First group of adult male Wistar rats was the control, second group received 0.5 mg kg

Results:

We have investigated a decrease in aTg amounts of control group (5.461±0.718) compared with drug treated rats with alprazolam (1.433±0.225) and haloperidol (1.21±0.228). (P

Conclusion:

We found that these two drugs may interfere with the thyroid physiology and metabolism.

Prevalences of autoimmune diseases in schizophrenia, bipolar I and II disorder, and controls

Previous studies on the relationship between autoimmune diseases, schizophrenia, and bipolar disorder are mainly based on hospital discharge registers with insufficient coverage of outpatient data. Furthermore, data is scant on the prevalence of autoimmune diseases in bipolar subgroups. Here we estimate the self-reported prevalences of autoimmune diseases in schizophrenia, bipolar disorder type I and II, and controls. Lifetime prevalence of autoimmune diseases was assessed through a structured interview in a sample of 9076 patients (schizophrenia N = 5278, bipolar disorder type I N = 1952, type II N = 1846) and 6485 controls. Comparative analyses were performed using logistic regressions. The prevalence of diabetes type 1 did not differ between groups. Hyperthyroidism, hypothyroidism regardless of lithium effects, rheumatoid arthritis, and polymyalgia rheumatica were most common in bipolar disorder. Systemic lupus erythematosus was less common in bipolar disorder than in the other groups. The rate of autoimmune diseases did not differ significantly between bipolar subgroups. We conclude that prevalences of autoimmune diseases show clear differences between schizophrenia and bipolar disorder, but not between the bipolar subgroups.

Neuroleptic malignant syndrome with thyroid disorder: An unusual case report

RATIONALE

Neuroleptic malignant syndrome (NMS) is a life threatening neurologic emergency associated with neuroleptic or antipsychotic agent use. NMS is rarely related to thyroid disease.

PATIENT CONCERNS

We report a case of NMS in a 66-year-old male with past medical history of paranoid schizophrenia on chlorpromazine, diabetes, hypertension and asthma, who presented with a humeral fracture after a fall. Patient developed hyperpyrexia, altered consciousness, autonomic instability, elevated serum creatine kinase (CK) without rigidity.

DIAGNOSES

CT head and workup for infection were negative. Electroencephalogram (EEG) showed generalized slow wave activity. Ultrasound revealed a large goiter with nodules.

INTERVENTIONS

Chlorpromazine was stopped due to concern of NMS. Patient was treated with cooling, fluid and electrolyte maintenance.

OUTCOMES

Patient slowly improved and CK level normalized. Thyroid-stimulating hormone (TSH) level trended down from 10.2 mIU/L to 0.02 mIU/L. Patient was discharged with aripiprazole.

LESSONS

Hypothyroidism predisposes patients to NMS by altering central dopaminergic systems. The typical symptoms may be masked by hypothyroidism. Thyroid dysfunction should be excluded in all patients with NMS. Discontinuing antipsychotic agents decreases TSH levels which maybe due to the negative feedback of dopaminergic activity. This is the first case report describing dramatic changes in TSH after discontinuing chlorpromazine in NMS.

Prevalence and determinants of thyroid disorders in elderly patients with affective disorders: lithium and nonlithium patients

OBJECTIVES

To determine the prevalence and determinants of thyroid dysfunction in older patients with affective disorders divided into lithium and nonlithium patients.

METHODS

This study was conducted as a retrospective cross-sectional study in patients of 65 years and older with affective disorders according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. The presence of thyroid disorders was determined on the index date defined as the date of the first available thyroid-stimulating hormone in 2005. The presence of thyroid disorder was diagnosed according to defined criteria and in case of a previous diagnosis, confirmed by researching the medical files. In a subgroup of 45 lithium patients, thyroperoxidase- and thyroglobulin antibodies were determined.

RESULTS

A total of 79 lithium patients and 85 nonlithium patients were included. The prevalence of hypothyroidism (subclinical and clinical) was 35.4% among the lithium patients, with women having a prevalence as high as 41.3% and men 12.6%. In the nonlithium patients, the prevalence was 7.1%; very close to that in the general population. No other determinant than female gender was identified. Seventeen of the 26 lithium patients were diagnosed with hypothyroidism in the first 31/2 years after the start of lithium. The prevalence of thyroid antibodies was 27% in 45 lithium patients, which was no different than the prevalence in the same age group in the general population.

CONCLUSION

The prevalence of hypothyroidism during lithium treatment was very high in the elderly, especially in women. Autoimmunity did not seem to play a major part in lithium-associated hypothyroidism in this age group. The timeframe between start of lithium and diagnosis of hypothyroidism suggests an individual susceptibility. The prevalence of hypothyroidism in nonlithium patients with affective disorders was not very different from the general population.

The clinical significance of subclinical thyroid dysfunction

Subclinical thyroid disease (SCTD) is defined as serum free T(4) and free T(3) levels within their respective reference ranges in the presence of abnormal serum TSH levels. SCTD is being diagnosed more frequently in clinical practice in young and middle-aged people as well as in the elderly. However, the clinical significance of subclinical thyroid dysfunction is much debated. Subclinical hyper- and hypothyroidism can have repercussions on the cardiovascular system and bone, as well as on other organs and systems. However, the treatment and management of SCTD and population screening are controversial despite the potential risk of progression to overt disease, and there is no consensus on the thyroid hormone and thyrotropin cutoff values at which treatment should be contemplated. Opinions differ regarding tissue effects, symptoms, signs, and cardiovascular risk. Here, we critically review the data on the prevalence and progression of SCTD, its tissue effects, and its prognostic implications. We also examine the mechanisms underlying tissue alterations in SCTD and the effects of replacement therapy on progression and tissue parameters. Lastly, we address the issue of the need to treat slight thyroid hormone deficiency or excess in relation to the patient's age.

Serotonin transporters: implications for antidepressant drug development

Due to the complexity of the disease, several hypotheses exist to explain the etiology of depression. The monoamine theory of depression suggests that disruptions in the serotonergic and noradrenergic systems result in depressive symptoms. Therefore, the serotonin transporter (SERT) has become a pharmacological target for treating these symptoms. This review will discuss what is known about the molecular interactions of antidepressants with SERT. The effects of antidepressants on SERT regulation and expression in addition to the receptors that may be involved in mediating these effects will be addressed. Specifically, how changes to SERT expression following chronic antidepressant treatment may contribute to the therapeutic benefits of antidepressants will be discussed. Furthermore, the effects of SERT gene polymorphisms on antidepressant efficacy will be examined. Finally, a brief overview of other hypotheses of depression will be addressed as well as factors that must be considered for future antidepressant development.

Possible malignant neuroleptic syndrome that associated with hypothyroidism

A 54-year-old woman with schizophrenia presented to hospital with unconsciousness, fever and marked muscle rigidity. She had been given fluphenazine decanoete 20 mg intramuscularly 15 days before the admission and she had continued taking haloperidol 20 mg daily and oral biperiden 2-4 mg. She was extremely rigid and unresponsive. On laboratory investigations revealed: serum sodium 120 mEq/l, creatinine phosphokinase 12,980 IU/l (normal up to 170), lactate dehydrogenase 1544 IU/l (150-500), free trioidothyronine < 1.00 pg/ml (1.5-4.5), free throxyine 0.76 ng/dl (0.8-1.9), thyroid stimulating hormone 1.14 microU/ml (0.4-4), cortisol (at 8.00 a.m.) 9 microg/dl (5-25). Antipsychotic drugs were withdrawn after admission. A diagnosis of secondary adrenal insufficiency and secondary hypothyroidism was made. Hormonal substitution with hydrocortisone and levothyroxine and correction of hyponatremia with intravenous hypertonic saline solution resulted in rapid improvement of symptoms and signs. It seems that the symptoms and signs of hypothyroidism and hyponatremia were attributed to acute psychosis in this patient. As a conclusion failure to recognize the endocrinopathy may not only produce recovery difficulties but also psychiatric and endocrine repercussions if psychotropic medications are given in such masked cases.

Evaluation of the association between St. John's wort and elevated thyroid-stimulating hormone

STUDY OBJECTIVE

To evaluate whether St. John's wort is associated with an elevation in thyroid-stimulating hormone (TSH) levels.

DESIGN

Retrospective case-control study

SETTING

Hamilton, Ontario; September 1998-May 1999.

SUBJECTS

Thirty-seven subjects with elevated TSH levels and 37 age- (+/- 6 yrs) and gender-matched subjects with normal TSH levels who resided in the same region.

MEASUREMENTS AND MAIN RESULTS

Exposure to St. John's wort during the 3-6 months before TSH measurement was assessed through a telephone interview. A total of 4 of 37 subjects with elevated TSH levels and 2 of 37 subjects with normal TSH levels had taken St. John's wort in that time period. The odds ratio for elevated TSH levels associated with taking St. John's wort was 2.12 (95% confidence interval [CI] 0.36-12.36).

CONCLUSION

This study suggests a probable association between St. John's wort and elevated TSH levels. However, because of the wide CIs surrounding the point estimate (which crosses unity), further investigation, including a large, prospective cohort study, is warranted.

In vitro and in vivo study of the antithyroid side effects of trimeprazine

Trimeprazine (TMP), a phenothiazine used as antipsychotic drug, was previously shown to induce a decrease in thyroid hormone serum levels in rats. Different mechanisms might be involved, mainly (i) a central mechanism, involving a reduction of thyroid-stimulating hormone (TSH) secretion; (ii) a peripheral mechanism, acting upon the synthesis of thyroid hormones, by inhibition of thyroperoxidase (TPO) or trapping of molecular iodine present in the thyroid gland. These different hypotheses were investigated in the present study, using in vitro and in vivo experiments. In vitro studies concerned TMP and its three main metabolites: trimeprazine sulphoxide (TSO), N-desmethyl trimeprazine (NDT), and 3-hydroxy-trimeprazine (3-OHT). TMP and TSO expressed a high affinity for iodine in vitro, contrary to NDT, which did not complex iodine. Only 3-OHT inhibited TPO in vitro. Administration of 5 mg/kg TMP ip twice daily for 11 days to Wistar rats induced a decrease of free triiodothyronine and free thyroxine (fT(3) and fT(4)) and a trend toward an increase of TSH serum levels. Thyroid concentrations of TMP, NDT, and TSO were significantly higher than serum levels, while 3-OHT was never detected. An iodine-supplemented diet administered to a group of rats treated with TMP significantly increased the thyroid concentration of TMP and TSO, but not that of NDT, while it did not affect the concentrations observed in serum and other organs. The increase in plasma TSH is not consistent with the central mechanism hypothesis, and the absence of TPO inhibition by TMP, TSO, and NDT contradicts the TPO inhibition hypothesis. On the contrary, three findings support the hypothesis of iodine trapping through formation of a complex with TMP and TSO: these molecules complex iodine in vitro, they accumulate in the thyroid, and their thyroid concentration is increased when the rats are fed an iodine-supplemented diet.