Review: thyroid function in psychiatric illness

The Intertwined Relationship Between an Overactive Thyroid and an Overactive Mind: A Case Report and Review of Literature

This case report presents the clinical scenario of a 45-year-old male patient who exhibited acute psychiatric symptoms as the initial manifestation of Graves' disease, a common etiology of hyperthyroidism. The patient presented with severe agitation, persecutory delusions, and auditory hallucinations, raising concerns about his mental health. Detailed diagnostic evaluations revealed thyroid dysfunction characterized by markedly low thyroid-stimulating hormone (TSH) levels, elevated free T4 levels, and increased total T3 levels, indicative of thyrotoxicosis. Elevated thyroid-stimulating immunoglobulin (TSI) levels further confirmed the diagnosis of Graves' disease. The patient received treatment with methimazole and propranolol to manage the hyperthyroidism, leading to the resolution of psychiatric symptoms. This case emphasizes the importance of considering thyroid function in patients presenting with acute psychiatric disturbances. This literature review explores the intricate relationship between hyperthyroidism, a condition characterized by the excessive production of thyroid hormones, and its impact on psychological and cognitive processes. Understanding the connection between an overactive thyroid and an overactive mind is crucial for clinicians and researchers to provide comprehensive care and treatment for affected individuals.

Non-thyroidal Illness Syndrome in an Infant With Acute Anorexia and Psychological Stress

Non-thyroidal illness syndrome (NTIS), a remarkable ensemble of changes in serum thyroid hormone concentration during acute illness, was first reported in the 1970s. While NTIS is not a form of hypothyroidism, it is characterized by a decrease in serum triiodothyronine (T3) or thyroxine (T4) or both with normal or decreased thyroid-stimulating hormone (TSH). Notably, it typically resolves without thyroid hormone replacement therapy. We report a case of paralytic ileus caused by NTIS in an infant with psychological stress. This case illustrates the development of NTIS during psychological stress, which can lead to severe symptoms such as those seen in pathological hypothyroidism.

From hormone replacement therapy to regenerative scaffolds: A review of current and novel primary hypothyroidism therapeutics

Primary hypothyroidism severely impacts the quality of life of patients through a decrease in the production of the thyroid hormones T3 and T4, leading to symptoms affecting cardiovascular, neurological, cognitive, and metabolic function. The incidence rate of primary hypothyroidism is expected to increase in the near future, partially due to increasing survival of patients that have undergone radiotherapy for head and neck cancer, which induces this disease in over half of those treated. The current standard of care encompasses thyroid hormone replacement therapy, traditionally in the form of synthetic T4. However, there is mounting evidence that this is unable to restore thyroid hormone signaling in all tissues due to often persistent symptoms. Additional complications are also present in the form of dosage difficulties, extensive drug interactions and poor patience compliance. The alternative therapeutic approach employed in the past is combination therapy, which consists of administration of both T3 and T4, either synthetic or in the form of desiccated thyroid extract. Here, issues are present regarding the lack of regulation concerning formulation and lack of data regarding safety and efficacy of these treatment methods. Tissue engineering and regenerative medicine have been applied in conjunction with each other to restore function of various tissues. Recently, these techniques have been adapted for thyroid tissue, primarily through the fabrication of regenerative scaffolds. Those currently under investigation are composed of either biopolymers or native decellularized extracellular matrix (dECM) in conjunction with either primary thyrocytes or stem cells which have undergone directed thyroid differentiation. Multiple of these scaffolds have successfully restored an athyroid phenotype in vivo. However, further work is needed until clinical translation can be achieved. This is proposed in the form of exploration and combination of materials used to fabricate these scaffolds, the addition of peptides which can aid restoration of tissue homeostasis and additional in vivo experimentation providing data on safety and efficacy of these implants.

Hypothyroidism and Depression: A Narrative Review

There has been an established relationship between hypothyroidism and depression. Studies have demonstrated that somatostatin and serotonin influence the hypothalamus-pituitary-thyroid axis, which links hypothyroidism to depression. Multiple studies concluded that undiagnosed, untreated, undertreated patients with hypothyroidism are at increased risk of developing depression. Autoimmune thyroiditis is also associated with an increased risk of depression. Elevated thyroid-stimulating hormone (TSH), antithyroglobulin (TgAb), and thyroid peroxidase antibodies (TPOAb) levels have all been linked to depression and an increased risk of suicide. Moreover, hypothyroidism is known to be one of the leading causes of treatment-resistant depression. Treating underlying hypothyroidism with thyroid replacement therapy could significantly improve mood disorders such as depression. Levothyroxine therapy is also used as adjunctive therapy to antidepressants in the management of depression, and it is known to improve the symptoms of depression rapidly when compared to antidepressants alone. This review strengthens the link between hypothyroidism and depression, and it also demonstrates how treating the underlying hypothyroidism in people who have been diagnosed with depression will be very beneficial.

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.

The hypothalamic-pituitary-thyroid axis and personality in a sample of healthy subjects

Thyroid hormones influence various brain pathologies, including psychiatric disorders. However, the relationship between these hormones and the psychological state in the normal, non-clinical population is poorly understood. We aimed to test whether serum levels of thyroid hormones are associated with personality in the healthy population. Thyrotropin (TSH), free T3 (FT4), total and free T4 (TT4 and FT4) concentrations were measured in the blood of 104 healthy participants (44% men) aged 18-59 (M=35±9). Personality traits were assessed using the revised short versions of the Temperament and Character Inventory (TCI-140) and the NEO Five-Factor Inventory (NEO-FFI). The data were analysed by correlational, regression, extreme groups and graphical techniques, which showed significant correlations between inter-individual variations in serum thyroid hormone levels and specific aspects of personality. In particular, high serum TSH was strongly associated with higher Persistence and Self-Directedness, and negatively correlated with Harm Avoidance on the TCI-140 and Neuroticism on the NEO-FFI, thus representing a more adaptive personality profile. Furthermore, increased FT4 was associated with lower Reward-Dependence, and increased TT4 was associated with lower Cooperativeness, representing a deficit in social attachment. Our data indicate that the relationship between thyroid hormones and personality in the healthy population might be rather more complex than the results obtained in clinical samples suggest.

The Pathology of Hyperthyroidism

This article reviews those pathologic lesions which are associated with clinical and/or biochemical hyperthyroidism. Beginning with the descriptive pathology of classical Graves' disease and the less common toxic nodular goiter and hyper-functioning thyroid nodules, this paper describes the effects of non-thyroidal hormones, glandular function (including pituitary and hypothalamic lesions), ectopic production of thyroid stimulating proteins by non-thyroidal neoplasms, exogenous drug reactions causing hyper-function and finally conditions associated with a mechanic- destructive cause of hyperthyroidism.

Pathogenesis of Hyperthyroidism

Hyperthyroidism is a form of thyrotoxicosis in which there is excess thyroid hormone synthesis and secretion. Multiple etiologies can lead to a common clinical state of "thyrotoxicosis," which is a consequence of the high thyroid hormone levels and their action on different tissues of the body. The most common cause of thyrotoxicosis is Graves' disease, an autoimmune disorder in which stimulating thyrotropin receptor antibodies bind to thyroid stimulating hormone (TSH) receptors on thyroid cells and cause overproduction of thyroid hormones. Other etiologies include: forms of thyroiditis in which inflammation causes release of preformed hormone, following thyroid gland insult that is autoimmune, infectious, mechanical or medication induced; secretion of human chorionic gonadotropin in the setting of transient gestational thyrotoxicosis and trophoblastic tumors; pituitary thyrotropin release, and exposure to extra-thyroidal sources of thyroid hormone that may be endogenous or exogenous. © 2017 American Physiological Society. Compr Physiol 7:67-79, 2017.

Thyroid function testing in an inpatient mental health unit

OBJECTIVE

Thyroid function tests are a common screening investigation for patients admitted to a psychiatric inpatient unit.

METHOD

This study aimed to retrospectively assess the clinical utility of routine thyroid function testing performed on newly admitted psychiatric patients over a 4-year period in Victoria, Australia via chart review of all abnormal results identified.

RESULTS

Our retrospective audit revealed only two cases where identification of thyroid dysfunction informed patient management. In each case, the patient had a known history of thyroid disease. In this audit period, 893 patients required screening to yield one clinically relevant abnormal result, costing AU$24,975.57.

CONCLUSION

Such low clinical utility does not support routine admission thyroid function tests for psychiatric inpatients. We conclude that thyroid function tests should only be performed where the history and clinical signs suggest a likely contribution of thyroid dysfunction to the psychiatric presentation.

Abnormalities of Thyroid Hormone Metabolism during Systemic Illness: The Low T3 Syndrome in Different Clinical Settings

Thyroid hormone abnormalities are common in critically ill patients. For over three decades, a mild form of these abnormalities has been described in patients with several diseases under outpatient care. These alterations in thyroid hormone economy are a part of the nonthyroidal illness and keep an important relationship with prognosis in most cases. The main feature of this syndrome is a fall in free triiodothyronine (T3) levels with normal thyrotropin (TSH). Free thyroxin (T4) and reverse T3 levels vary according to the underlying disease. The importance of recognizing this condition in such patients is evident to physicians practicing in a variety of specialties, especially general medicine, to avoid misdiagnosing the much more common primary thyroid dysfunctions and indicating treatments that are often not beneficial. This review focuses on the most common chronic diseases already known to present with alterations in serum thyroid hormone levels. A short review of the common pathophysiology of the nonthyroidal illness is followed by the clinical and laboratorial presentation in each condition. Finally, a clinical case vignette and a brief summary on the evidence about treatment of the nonthyroidal illness and on the future research topics to be addressed are presented.

Neuropsychiatric manifestations of thyroid disease

The interface between thyroid hormone action and neuropsychiatric function is intricate, and several mechanisms of thyroid hormone uptake into brain tissues, hormone activation, and influences on neurotransmitter generation have been identified. Symptoms of hypothyroidism are nonspecific, whereas those attributed to thyrotoxicosis may be more characteristic. Neuropsychiatric manifestations triggered by thyroid dysfunction likely respond well to reestablishment of the euthyroid state, although some patients have persistent complaints. The addition of LT3 to ongoing LT4 replacement has yet to be definitively shown to be advantageous. Treatment of euthyroid depression with LT3 in addition to antidepressant therapy lacks convincing evidence of superior outcomes.

A paradoxical difference in relationship between anxiety, depression and thyroid function in subjects on and not on T4: findings from the HUNT study

OBJECTIVE

There have been conflicting reports on the relationship between thyroid function and mood between studies in subjects on T4 and the general population not on T4. We investigated this relationship in a large catchment area-based study.

DESIGN

We analysed data on serum TSH levels and Hospital Anxiety and Depression Scale (HADS) scores from the HUNT 2 study (age > or = 40 years). Following a test for interaction, analyses were performed separately in females on T4 (n = 1265) and in people not on T4 (males n = 9319 and females n = 17 694).

RESULTS

More females on T4 had high depression and anxiety scores than females not on T4 (depression 18.4%vs. 13.0%, P < 0.001, anxiety 23.4%vs. 18.7%, P < 0.001). In those not on T4, there was an inverse association between serum TSH and depression score in males (B coefficient = -0.61, 95% CI -0.91 to -0.24, P = 0.001) though not in females (B coefficient = -0.07, -0.33 to 0.19), and an inverse association between TSH and anxiety score in both genders (B coefficient for males = 0.68, 95% CI -1.04 to -0.32, P < 0.001; females -0.37, 95% CI -0.67 to -0.08, P = 0.01). In contrast, in females on T4, TSH was positively associated with both depression (B coefficient = +0.27, 95% CI 0.02 to 0.51, P < 0.05) and anxiety (B coefficient = +0.29, 95% CI 0.01 to 0.56, P < 0.05).

CONCLUSIONS

There is a different relationship between thyroid function and depression and anxiety in females on T4 compared with individuals with no thyroid disease. This group also has a higher prevalence of depression and anxiety.

Low yield of thyroid-stimulating hormone testing in elderly patients with depression

Although hypothyroidism is purportedly an important cause of depression, prior studies have involved small samples of young people and produced conflicting results. We examined the yield of thyroid-stimulating hormone (TSH) testing in a large group of elderly patients with major depression or dysthymic disorder. The study sample comprised 883 outpatients aged 60 years or older from 18 primary care sites enrolled in the intervention arm of a clinical trial of depression management. Thyroid function was assessed by a single TSH value. Depressive diagnoses were confirmed with the Structured Clinical Interview for DSM-IV (SCID) and depression severity was assessed with the HSCL-20, a modified depression scale of the Hopkins Symptom Checklist. TSH results were available for 725 (82.1%) participants. Although 32 (4.4%) of those tested had TSH>5 mIU/L, the vast majority (27/32) had marginally elevated results (5.1-9.4 mIU/L). Only five patients (0.7%) had TSH levels >10 mIU/L. Patients with elevated TSH did not differ from those with TSH < or = 5 mIU/L in the severity or symptom pattern of depression as measured by the baseline HSCL-20 score (P=.37) or SCID score (P=.44). These findings should caution physicians against acceptance of borderline TSH values as the primary cause of a patient's clinical depression.

A relação entre a função tireoidiana e a depressão: uma revisão

OBJETIVO: O papel da função tireoidiana nas doenças depressivas é pouco claro. Embora existam algumas evidências de que discretas alterações tireoidianas predisponham a casos de depressão, as anormalidades específicas envolvendo a tireóide e os quadros depressivos permanecem pouco conhecidas. Serão destacados nesta revisão os principais achados envolvendo os quadros depressivos e a função tireoidiana, com especial atenção na participação das monoaminas cerebrais nesta relação. MÉTODO: Foram realizados levantamento no sistema Medline e na literatura. RESULTADOS: Existem evidências de atividade alterada do eixo hipotálamo-hipófise-tireóide (HHT) em alguns casos de depressão, que incluem: aumento dos níveis de T4, resposta alterada do TSH pós-estímulo com TRH, presença de anticorpos antitireoidianos e concentração elevada de TRH no LCR. A relação entre estas anormalidades, as principais monoaminas cerebrais e os subtipos de quadros depressivos é complexa e ainda não permite o estabelecimento de hipóteses diretas de compreensão. CONCLUSÕES: Após anos de pesquisas, permanece pouco esclarecida a importância da relação entre o eixo HHT e as depressões, assim como os mecanismos subjacentes às alterações tireoidianas encontradas nos pacientes deprimidos. Portanto, mais pesquisas serão necessárias para uma melhor compreensão do papel do eixo HHT na patogênese e no tratamento dos quadros depressivos.

Neuropeptides involved in the pathophysiology of schizophrenia and major depression

The present review summarizes the findings on the role of neuropeptides in the pathophysiology of schizophrenia and major depression. Several neuropeptides as vasopressin and endorphins in particular, beta-endorphin and gamma-type endorphins, cholecystokinin (CCK), neurotensin, somatostatin and Neuropeptide Y have been implicated in schizophrenia. During the last decade, however, few attempts to explore the significance of most of these and other neuropeptides in the pathophysiology of the disease or their therapeutic potential are found in the literature. An exception is neurotensin, which exerts neuroleptic-like effects in animal studies, while CSF, brain and blood studies are inconclusive. Things are different in major depression. Here much attention is paid to the endocrine abnormalities found in this disorder in particular the increased activity of the hypothalamic-pituitary-adrenal (HPA) axis. Neuropeptides as corticotropin-releasing hormone (CRH), vasopressin and corticosteroids are implicated in the symptomatology of this disorder. As a consequence much work is going on investigating the influence of CRH and corticosteroid antagonists or inhibitors of the synthesis of corticosteroids as potential therapeutic agents. This review emphasizes the role of vasopressin in the increased activity of the HPA axis in major depression and suggests exploration of the influence of the now available non-peptidergic vasopressin orally active V1 antagonists.

Case finding and screening strategies for thyroid dysfunction

BACKGROUND

A case can be made for routine testing for thyroid dysfunction (TD) in women aged over 50 years once every 5 years when they present for medical care (case finding). This recommendation is based on: (i) the prevalence of TD, predominantly hypothyroidism, (ii) the insensitivity of standard clinical assessment in detecting even overt TD, (iii) the sensitivity of a single test, serum thyroid stimulating hormone (TSH), in identifying both over- and under-function, (iv) the probable adverse consequences of failure to recognize even mild TD, (v) the safety and effectiveness of treatment, and (vi) presumed lack of adverse effect from the testing program.

METHODS

A normal serum TSH value has a high negative predictive value in ruling out primary TD; if TSH is abnormal, measurement of serum free thyroxine (T(4)) and further clinical assessment are both required to establish the degree of TD.

RESULTS

Case finding identifies more "subclinical" or mild TD (abnormal TSH, normal T(4) and triiodothyronine (T(3))), than overt disease, but a major benefit of widespread testing is the earlier detection and treatment of unsuspected overt disease. There is now evidence that mild TD has adverse consequences and should not merely be regarded as a prognostic indicator, but there is still no consensus whether there is a causal relationship between mild thyroid failure and dyslipidemia.

CONCLUSIONS

A case can be made for treatment of both mild thyrotoxicosis and hypothyroidism, but the therapeutic decision is generally simpler for hypothyroidism.

Evaluation of the patient with a suspected thyroid disorder

The principal types of thyroid disorders described herein can be recognized and evaluated clinically and biochemically by the obstetrician/gynecologist. Most patients with diffuse goiter should be referred for further evaluation and an RAI scan arranged while this consultation is awaited. Patients with solitary thyroid nodules should be referred for FNAB. Primary hypothyroidism without significant goiter can be treated without specialist referral, except in patients at high risk for ischemic coronary disease or arrhythmia. Primary hyperthyroidism, apart from subacute and postpartum thyroiditis, should be referred for specialist evaluation and definitive therapy. An RAI scan and uptake should be ordered, and beta-blocker therapy can be initiated as interim therapy in symptomatic patients. Patients with secondary (i.e., hypothalamic- or pituitary-based) thyroid dysfunction should always be referred for evaluation and treatment of the primary intracranial cause. There are several causes of abnormal thyroid function tests in apparently euthyroid patients, and the clinical context often provides important evidence of their nature. Clinical judgment is an important factor in knowing when to arrange specialist consultation.

Expanding the horizons of depression: beyond the monoamine hypothesis

The monoamine hypothesis has dominated our understanding of depression and of pharmacological approaches to its management and it has produced several generations of antidepressant agents, ranging from the monoamine oxidase inhibitors (MAOIs), through tricyclics (TCAs) and selective serotonin reuptake inhibitors (SSRIs), to the recently introduced selective noradrenaline reuptake inhibitor (NARI), reboxetine. Greater receptor selectivity has improved tolerability, but not efficacy, when newer compounds are compared with the original tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors. Essentially, the newer antidepressants have the same distinguishing feature as older ones, i.e. acute enhancement of monoaminergic neurotransmission. The monoamine hypothesis cannot conclusively link the acute biochemical action of antidepressants on monoamine levels with their delayed clinical effect of 10-14 days, nor can it explain the mode of action of antidepressants that are effective despite being very weak inhibitors of monoaminergic transmission (e.g. iprindole) or, incongruously, enhancing monoamine uptake (e.g. tianeptine). Compared with other fields of medicine, there has been a lack of progress in understanding the pathophysiology of depression and producing truly novel antidepressant agents. Other biological approaches to depression, such as overactivity of the hypothalamic-pituitary-adrenal axis, hippocampal neural plasticity in response to stress, and the link between the inflammatory response and depression, offer new approaches to finding pharmacological agents, aided by improved techniques for visualising the human brain, better animal models, and increased knowledge of human markers of depression. Copyright 2001 John Wiley & Sons, Ltd.

[Non-thyroid illness" or changed thyroid hormone parameter syndrome with non-thyroid illnesses]

BACKGROUND

The multiple effects of systemic illness on thyroid economy are commonly referred to "non-thyroidal illness" (NTI) or "sick euthyroid syndrome". The various aspects of this common syndrome are summarized in this article.

STUDIES

Results of the relevant studies published during the past 25 years were evaluated. The influence of the underlying illness and of drug administration was especially emphasized.

RESULTS

The most common abnormalities in NTI are 1. the "low-T3 syndrome" due to a decreased T3 generation from T4 by a reduced activity of 5'-deiodinase (a selenoprotein); 2. the "low-T3 low-T4 state", which is associated with a poor prognosis. The low T4-levels are related to a binding inhibitor that displaces T4 from its binding proteins. However, there exists some controversy regarding the character of this binding inhibitor. 3. The high-T4 state is often found in acute psychiatric and liver diseases. The nutritional status of the patients and drugs known to influence thyroid hormone parameters have to be considered when patients with NTI are evaluated. Some difficulties may arise, when there is evidence of coexisting thyroid disease. Here aside from further biochemical evaluation such as thyroid antibodies, thyroid ultrasound and a thyroid scan have to be performed.

CONCLUSION

NTI is associated with various alterations in thyroid hormone parameters when no intrinsic thyroid hormone disease exists. The severity of NTI reflects clinical outcome and clinical amelioration is associated with normalization of thyroid hormone parameters. There is no need for specific therapeutic intervention such as the administration of thyroid hormones in patients with the various forms of the NTI-syndrome.

The thyroid axis and depression

Hypothyroidism may give rise to frank depression that usually responds to thyroxine therapy. Depressed subjects with subclinical hypothyroidism and/or autoimmune thyroiditis should probably also be treated similarly. Most patients with depression, although generally viewed as chemically euthyroid, have alterations in their thyroid function including slight elevation of the serum thyroxine (T4), blunted thyrotropin (TSH) response to thyrotropin-releasing hormone (TRH) stimulation, and loss of the nocturnal TSH rise. These changes are generally reversed following alleviation of the depression. The role of adjuvant triiodothyronine (T3) treatment in resistant depression has not been established, but the data suggest that it will be beneficial in about 25% of cases. However, controlled trials to establish this approach are needed. The underlying mechanism leading to the beneficial response from T3 is unknown, but may reflect brain hypothyroidism in the context of systemic euthyroidism. The hypothalamus in culture, which is analogous to a deafferentated hypothalamus in vivo, shows a paradoxic increase in TRH production after glucocorticoid stimulation. It is known that in human depression there is a functional disconnection of the hypothalamus with impairment of the inhibitory glucocorticoid feedback pathway from the hippocampus to the hypothalamus that results in the typical elevated cortisol levels and impaired dexamethasone suppression. It is postulated that a similar situation prevails with regards to the thyroid axis and that the increased T4 in depression, as well as the blunted TSH response to exogenous TRH, reflects glucocorticoid activation of the TRH neuron leading to increased TRH secretion with resultant down regulation of the TRH receptor on the thyrotrope. Normalization of thyroid function after treatment may result in part from an inhibitory response of the TRH neuron to antidepressant medication, although other effects may also be responsible.

Biochemical testing of thyroid function

Various published guidelines recommending serum thyrotropin (TSH)-first thyroid testing are outlined. The entities called "subclinical hypothyroidism" and "subclinical hyperthyroidism" are defined on the basis of abnormal TSH concentrations and normal values of other biochemical thyroid tests. The controversies about follow-up and treatment of these disorders are discussed. The laboratory experience of Mayo Clinic Rochester in using TSH-first thyroid testing and the subsequent implementation of a thyroid test ordering cascade are presented. Finally, recommendations are given for further optimizing laboratory testing for thyroid disorders.

Utility of thyroid function screening in adolescent psychiatric inpatients

OBJECTIVE

Thyroid function abnormalities have been associated with psychiatric symptoms. This study examines the utility of thyroid screening among adolescent psychiatric inpatients.

METHOD

A retrospective chart review of 196 first-time admissions to an adolescent psychiatric unit was conducted. Charts were screened for demographics, presence/absence of thyroid function testing, history of thyroid disease, medication/illicit substance use, and other factors of influence on thyroid testing. Thyroid test results were reviewed for abnormalities.

RESULTS

Thyroid function testing was conducted in 150 of the 196 admissions. Fifty-two patients had abnormalities, most of which were isolated abnormalities of thyroxine (T4) or triiodothyronine uptake (T3U). Laboratory diagnosis of hyperthyroidism and mild hypothyroidism was met by two and eight patients, respectively; five had profiles that were normal upon subsequent testing 1 week later. None of the patients was symptomatic, and none required thyroid supplementation or antithyroid medications. Gender differences in T4 and T3U were noted, and age was positively correlated with T3U.

CONCLUSIONS

Thyroid function tests may be spuriously abnormal in routine screening of newly admitted psychiatric patients. Routine thyroid screening among adolescent psychiatric inpatients is unwarranted except in patients who display physical signs or symptoms suggestive of thyroid disease.

Euthyroid sick syndrome in psychiatric inpatients

Numerous disorders are associated with euthyroid sick syndrome (ESS). This retrospective study examines the incidence and circumstances of ESS among 3188 psychiatric inpatients. There were 324 patients (10.2%) who met strictly defined criteria for ESS. Of these, 95 were hyperthyroxinemic (HT), 6 were hypothyroxinemic, 179 had mildly elevated thyroid-stimulating hormone (HTSH), and 47 had suppressed TSH. All were classified by DSM-III-R discharge diagnoses, encompassing five categories. chi 2 tests of significance of the 95 HT and 179 HTSH subjects revealed the following: 1) no relationship with age or gender; 2) the frequencies of HT and HTSH differed significantly (p < .05 and p < .01, respectively) across the five psychiatric categories; 3) HT frequency was highest in mood disorders (HT in mood versus others p < .02); and 4) HTSH frequency was highest in substance abuse (HTSH in substance abuse versus others p < .02). In conclusion, ESS is common in psychiatric inpatients, especially HT and HTSH; pathophysiologic mechanisms may vary according to psychiatric diagnosis.

Thyroid evaluation of hospitalized psychiatric patients: the role of TSH screening for thyroid dysfunction

The incidence and pattern of changes in thyroid function tests were studied in acutely hospitalized psychiatric patients and the cost effectiveness of a systematic screening program for thyroid dysfunction was estimated. Thyroid testing was performed on 1275 of 1424 (90%) admissions to the psychiatric wing of Strong Memorial Hospital between April 1, 1993 and March 30, 1994. Discharge samples were obtained in 232 patients who were hospitalized at least 2 days; 163 patients were admitted multiple times. Psychiatric diagnosis was coded using DSM-III-R criteria. TSH, T4, free T4, and T3 levels were measured within 48 h of admission. TSH values were most frequently abnormal (7.8%) and free T4 the least (1.3%). Admission and discharge thyroid tests were similar. Significant differences in the four parameters of thyroid function were present among the psychiatric groups. By analysis of variance every 1 microU/mL increase in TSH levels was associated with a 2.5% increase in length of stay (LOS) (95% confidence intervals: 0.21%, 4.75%), holding psychiatric diagnosis, age, and gender constant. For patients with elevated TSH levels, the average LOS was increased by 10.7 days (95% confidence intervals: 2.8, 18.7 days). It is concluded that patients hospitalized for psychiatric illness have an incidence of thyroid dysfunction at or slightly higher than the general population. However, patients with elevated TSH levels are hospitalized longer than those with normal or suppressed values.

Clinical use of sensitive assays for thyroid-stimulating hormone

OBJECTIVE

To review the optimal use of sensitive assays for thyroid-stimulating hormone (TSH) by clinicians.

METHODS

The available literature pertinent to the clinical application of sensitive TSH testing was identified through a systematic MEDLINE search and reviewed. Selection of materials for inclusion was based on clinical validity of the data and relevance to the study question.

SYNOPSIS

Sensitive TSH assays have contributed greatly to our basic knowledge of thyroid physiology and are a powerful clinical tool in the diagnosis and treatment of thyroid disease. The clinical applicability of these assays, as is our understanding of their appropriate use, is rapidly expanding. Based upon the best evidence and current understanding of thyroid physiology, strategies are presented for appropriate use of sensitive TSH assays in healthy outpatients, in patients who are likely to have a disturbed hypothalmic-pituitary-thyroid axis, and in patients on levothyroxane therapy.

CONCLUSIONS

Although many clinical questions regarding the use of sensitive TSH assays remain to be studied, it has emerged as a powerful tool for the diagnosis and management of thyroid disease. Optimal use of sensitive TSH assays requires an understanding of TSH physiology and measurement, coupled with appropriate application and interpretation in specific clinical settings.

Does thyroid hormone have a role as adjunctive therapy in depression?

Depression is associated with abnormalities of the thyroid axis, but the role of thyroid hormone therapy is controversial. In patients presenting with depression, the thyroid status should be carefully evaluated since hypothyroidism can cause depression. Frank hypothyroidism should be treated in the usual fashion with L-thyroxine, which may reverse the depressive state. If subclinical hypothyroidism and/or autoimmune thyroiditis are present, T3 adjuvant administration (25 micrograms/day) should be seriously considered in patients resistant to tricyclic antidepressant (TCA) (and probably also) serotonin selective reuptake inhibitor (SSRI) medication. The possible efficacy of adjuvant T4 in reversing the depression of such subjects appears less than T3. In depressed patients with TCA or SSRI resistance and no evidence of hypothyroidism, the data available do not establish the therapeutic role of T3 in this situation. Multicenter controlled studies of T3 adjuvant therapy are required. The possible mechanisms through which T3 adjuvant therapy might be efficacious are discussed.

The use of haematological screening tests in acute psychogeriatric admissions

Objective: Case notes on 116 patients aged 65 or more admitted to a general psychiatry hospital over a three month period were examined to assess the current use of haematological screening tests.

Method: Retrospective justification for tests performed, rate of abnormal results, and consequences for patient management were assessed by case note review.

Results: A total of 200 screening tests, 105 of which appeared justified, were performed; 66 patients were screened, of whom 85% had at least one abnormal result. Those who were older were less likely to be screened. There was no relationship between diagnosis and being screened. Of the 90 abnormal results received, less then one third affected clinical management.

Conclusions: The financial and other costs of screening tests are discussed. The current use of haematological screening tests in this population appears erratic and often adds little to patient management.

Subclinical hypothyroidism: neurobehavioral features and beneficial effect of L-thyroxine treatment

Frank hypothyroidism is known to induce neurological and mental dysfunction. The aim of this study was to assess selected neuropsychological and behavioral features by means of standardized tests in a group of 14 patients with subclinical hypothyroidism who were free from neuropsychological complaints and to evaluate the possible effects of L-thyroxine treatment on their performance. Patients were submitted to the Crown and Crisp Experiential Index and to the Wechsler Memory Scale; their ratings on the neurobehavioral tests and their thyroid hormone profile were compared to those of a control group of 50 age- and sex-matched subjects. Comparison was also carried out between pretreatment ratings and those obtained following a 6-month L-thyroxine course (0.1-0.15 mg/day). The Wechsler Memory Scale ratings showed a significant impairment in patients' memory-related abilities [memory quotient (MQ) = 89.1 +/- 2.9; P = 0.002 (patients versus controls)]; the Crown and Crisp Experiential Index ratings demonstrated moderate differences between untreated patients and controls with respect to hysteria (P = 0.03), anxiety (P = 0.05), somatic complaints (P = 0.0005), and depressive features (P = 0.002) scales; the total score was also significantly higher (42.0 +/- 3.8; P = 0.005). After L-thyroxine treatment the patients' performances showed an improvement in memory skills, as evaluated by the Wechsler Memory Scale [MQ = 99.9 +/- 4.0; P = 0.002 (treated versus untreated)]; somatic complaints (P = 0.02) and obsessionality (P = 0.04) ratings and the Crown and Crisp Experiential Index total score (P = 0.04) significantly decreased with respect to untreated patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychotropic drug use in the medically ill. Part II

Underlying medical illness and drug interactions may make the use of psychotropic agents problematic in some physically ill patients. This overview, published in two parts, discusses six major classes of psychotropic medications (cyclic antidepressants, monoamine oxidase inhibitors, benzodiazepines, neuroleptics, lithium, psychostimulants, and carbamazepine) and examines their use in the setting of specific types of medical illnesses (e.g., cardiovascular, pulmonary, hepatic, and renal disease). Practical considerations in using psychotropic medications in medical-surgical patients--particularly those who are elderly or medically debilitated--will receive special emphasis.