Free thyroxine levels are associated with cognitive changes in individuals with a first episode of psychosis: A prospective 1-year follow-up study

The association between plasma thyroxine levels and neurocognitive impairment in early-onset schizophrenia and other psychosis spectrum disorders

BACKGROUND/AIM

Limited studies have delved into the association between thyroid hormones and neurocognition in schizophrenia. We aimed to evaluate the relationship between thyroid hormone levels and neurocognitive functions in patients with schizophrenia and other psychosis spectrum disorders (SSD).

METHOD

A total of 135 patients with early-onset SSD were included in the study. The participants underwent a cognitive assessment. Blood samples were collected to measure serum levels of thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3). Subgroup analyses were conducted based on the severity of the psychosis.

FINDINGS

The results revealed a significant association between fT4 levels and various cognitive domains, including processing speed, verbal fluency, working memory, verbal learning, verbal memory, and visual memory. However, serum TSH and fT3 levels exhibited no significant association with neurocognitive impairment in adjusted linear regression models. Specifically, the correlation between fT4 levels and global cognition was more pronounced in patients with higher scores.

CONCLUSIONS

Serum fT4 levels were associated with the performance across various cognitive domains in cases of early-onset psychotic disorders. This correlation was accentuated among patients with higher illness severity. Future studies could focus on the effects of specific pathways that can affect the course and progression of psychosis.

Relationship between thyroid-stimulating hormone, BDNF levels, and hippocampal volume in antipsychotic-naïve first-episode psychosis patients

Introduction

Thyroid hormones play an essential role in hippocampal development, a key structure in psychosis. However, the role of these hormones in first-episode psychosis (FEP) has received limited attention. It has been hypothesized that thyroid hormones could cause morphological modifications in the hippocampal structure through the upregulation of brain-derived neurotrophic factor (BDNF). In this study, we primarily aimed to determine the relationship between thyroid-stimulating hormone (TSH) levels, peripheral BDNF levels, and hippocampal volume in antipsychotic-naïve FEP patients. We also aimed to determine whether TSH levels were associated with clinical symptomatology.

Materials and methods

A total of 50 antipsychotic-naïve FEP patients were included in the study. At baseline, we collected fasting blood samples and registered sociodemographic and clinical variables (substance use, DUP, PANSS, GAF, and CDSS). Structural T1 MRI was performed at baseline to quantify brain volumes. No control group was used for this study.

Results

Of the 50 patients, more than one-third (36%) presented alterations in TSH levels, mainly elevated levels (32% of patients). The TSH levels were inversely correlated with both peripheral BDNF and hippocampal volume. On the multivariate analysis, the model that best predicted the relative hippocampal volume was a single variable model (TSH levels). No significant association was observed between TSH levels and clinical symptomatology.

Discussion

These results suggest that thyroid hormones could have a neuroprotective effect on the hippocampus in FEP patients, possibly through their effect by increasing BDNF concentrations, which could attenuate brain injury and neuroinflammation. Nevertheless, thyroid hormones could also affect hippocampal volume through other pathways.

Selected neuroendocrine factors as potential molecular biomarkers of early non-affective psychosis course in relation to treatment outcome: A pilot study

The aim of this pilot study was to find whether the dysregulation of neuroendocrine biomarker signaling pathways in the first episode of non-affective psychosis is a predictive factor of treatment outcome. Patients with the first episode of non-affective psychosis (N = 29) were examined at admission, at discharge, and at follow-up (N = 23). The biomarkers included serum aldosterone, cortisol, free thyroxine, thyroid stimulating hormone, and prolactin. We revealed lower baseline aldosterone and higher baseline cortisol concentrations in patients with very good outcome compared to those with good outcome after one year. We failed to reveal any significant association between treatment outcome and neurohumoral biomarkers in the whole sample at 1-year follow-up. However, baseline aldosterone concentrations negatively correlated with total PANSS scores at the discharge. Lower baseline aldosterone and higher baseline cortisol concentrations have the potential to predict a more favorable outcome for patients with the first episode of psychosis.

Altered neutrophil-to-lymphocyte ratio in patients with non-affective first episode psychosis and its relationship with symptom severity and cognitive impairment

Signatures of immune dysregulation as clinical biomarker for psychosis have remained unclear. We aimed to compare the Neutrophil-to-lymphocyte ratio (NLR) of patients with acute non-affective first-episode psychosis (FEP) with healthy controls after accounting for emotional states. We also explored the associations of NLR with symptom severity, onset profile and cognitive functions. The NLR was enumerated from complete blood count taken within a week of assessment. All FEP patients were rated on the Positive and Negative Syndrome Scale (PANSS) and the Clinician Global Impression-Severity (CGI-S) with verbal memory and executive functions assessed with the Cambridge Neuropsychological Test Automated Battery. Prevailing emotional state was measured with Beck Depression Inventory-II and Beck Anxiety Inventory. Out of seventy-nine consecutive FEP patients presenting to the study site, twenty-seven subjects were eligible and recruited. Twenty-seven age-/sex-matched controls were recruited. FEP patients had an NLR of 1.886 over the controls after accounting for scores on emotional states. The NLR of FEP patients was positively associated with CGI-S scores, PANSS positive symptom, disorganization and excitation scores. There was no significant correlation between NLR with the duration of untreated psychosis and cognitive performances. These findings support using NLR as a clinical biomarker in FEP, purporting further prospective study to measure NLR changes in the course of treatment.

Association between free thyroxine levels and clinical phenotype in first-episode psychosis: a prospective observational study

Aim

To determine whether thyroid hormone levels are associated with a specific clinical phenotype in patients with first-episode psychosis (FEP).

Methods

Ninety-eight inpatients experiencing FEP and with less than 6 weeks of antipsychotic treatment were included in the study and were followed up for one year. Baseline psychiatric evaluation included assessment of prodromal symptoms, positive and negative symptoms, depressive symptoms, stressful life events and cycloid psychosis criteria. Thyroid function (thyroid-stimulating hormone (TSH) and free thyroxin (FT4)) was determined at admission. Partial correlation analysis was conducted to analyse the correlation between levels of TSH/FT4 and symptoms. Logistic regression was performed to explore the association between psychopathological symptoms, 12-month diagnoses and thyroid hormones while adjusting for covariates.

Results

Patients with prodromal symptomatology showed lower baseline FT4 levels (OR = 0.06; p = 0.018). The duration of untreated psychosis (DUP) was inversely associated with FT4 concentrations (r =  - 0.243; p = 0.039). FEP patients with sudden onset of psychotic symptoms (criteria B, cycloid psychosis) showed higher FT4 levels at admission (OR = 10.49; p = 0.040). Patients diagnosed with affective psychotic disorders (BD or MDD) at the 12-month follow-up showed higher FT4 levels at admission than patients diagnosed with nonaffective psychosis (schizophrenia, schizoaffective) (OR = 8.57; p = 0.042).

Conclusions

Our study suggests that higher free-thyroxine levels are associated with a specific clinical phenotype of FEP patients (fewer prodromal symptoms, shorter DUP duration and sudden onset of psychosis) and with affective psychosis diagnoses at the 12-month follow-up.

Şizofreni hastalarında TSH, fT3 ve fT4 düzeylerinin nörobilişsel belirtiler üzerine etkisi

Amaç: Bu çalışmamızda ötiroid psikoz hastalarında tiroid hormon düzeyleri ile pozitif, negatif, genel ve bilişsel belirtiler arasındaki ilişkiyi incelemeyi amaçladık. Gereç ve Yöntem: Çalışmaya 33 şizofreni hastası dahil edildi. Katılımcıların sosyodemografik ve klinik verileri, Pozitif ve Negatif Belirtileri Değerlendirme Ölçeği (PANSS), İşlevselliğin Genel Değerlendirilmesi Ölçeği (IGD), Klinik Global İzlenim Ölçeği (KGI) skorları kaydedildi. İz sürme, Sözel Akıcılık Testi, İleri ve Geri Sayı Menzili ile Wisconsin Kart Sayma Testinden (WKST) oluşan bir nörobilişsel batarya uygulanan hastaların bilişsel performanslarının TSH, sT3 ve sT4 düzeyleri ile ilişkisi araştırıldı. Bulgular: sT4 düzeyleri ile İz Sürme B (r=-,376; p=0,031) ve Sözel Akıcılık test (p=,355; p=0,043) performansları arasında anlamlı derecede ilişki saptandı. Linear regresyon modelinde sT3 düzeylerinin WKST- tamamlanan kategori sayısını (UB=1.680; p=0.029) anlamlı derecede yordadığı saptandı.. Sonuç: Çalışmamızın sonuçları sT3 ün özellikle yürütücü işlevler üzerinde sT4’e kıyasla daha belirleyici etkileri olduğunu düşündürmüştür. İleride yapılacak daha geniş katılımlı araştırmalar, bilişsel belirtilerin tedavisinde tiroid hormon replasmanının etkinliğini belirlemek açısından önemli görünmektedir.

Redefining the Cut-Off Ranges for TSH Based on the Clinical Picture, Results of Neuroimaging and Laboratory Tests in Unsupervised Cluster Analysis as Individualized Diagnosis of Early Schizophrenia

Thyroid abnormalities, including mild forms of hypothyroidism and hyperthyroidism, are reported as risk factors for the development of a number of neuropsychiatric disorders, including schizophrenia. The diagnostic process still takes into account the extreme ranges of the accepted reference values for serum TSH since the concentration of free thyroxine in the serum does not change by definition. TSH mU/L cut-off values in psychiatric patients are currently clinically considered in the case of extremely high serum TSH levels (>4.0 mU/L). The results obtained in this study suggest that the clinically significant value has a lower TSH cut-off point with an upper limit of 2–2.5 mU/L. The criteria for the differential diagnosis of patients with schizophrenia, however, mainly take into account statutory reference ranges without a background related to the history of thyroid diseases in the family. The results indicate the need to lower the upper cut-off values for TSH among patients with early psychosis, which is related to the potential clinical significance of the obtained values both in the field of clinical evaluation and neuroimaging and laboratory evaluation parameters. The cut-off points obtained with the prior available knowledge coincided with the values established in the unsupervised clustering method, which further confirms the legitimacy of their use in the individualized diagnosis strategy of schizophrenia.

Thyroid hormones in persons with schizophrenia: A systematic review and meta-analysis

There is accumulating evidence that individuals with schizophrenia show altered levels of thyroid hormones. However, a qualitative and quantitative synthesis of findings in this field has not been performed so far. Therefore, we aimed to perform a systematic review and meta-analysis of studies investigating the levels of thyroid-stimulating hormone (TSH), free thyroxine (fT4), total thyroxine (tT4), free triiodothyronine (fT3) and total triiodothyronine (tT3) in multiple-episode schizophrenia (MES) and first-episode psychosis (FEP). Electronic databases were searched from their inception until 30th May 2020 by two independent reviewers. Random-effects meta-analyses and meta-regression analyses were performed. Altogether, 19 studies were included. Persons with FEP had significantly lower TSH levels (5 studies, g = -0.26, 95%CI: -0.47 to -0.06, p = 0.013, I² = 21.3%), higher fT4 levels (3 studies, g = 0.58, 95%CI: 0.15-1.01, p = 0.008, I² = 64.6%) and lower tT3 levels (2 studies, g = -0.60, 95%CI: -0.82 to -0.37, p < 0.001, I² = 0%) compared to controls. Elevated TSH levels were found in persons with MES (13 studies, g = 0.20, 95%CI: 0.02-0.39, p = 0.031, I² = 50.0%). Our findings imply that the levels of TSH might be decreased in persons with FEP and increased in those with MES. Other alterations need to be confirmed by additional studies. These findings imply the need to monitor the levels of TSH and thyroid hormones from the onset of psychosis.

Cognitive functioning in first episode psychosis. Gender differences and relation with clinical variables

AIMS

to study the differences in cognitive functioning in patients and controls. In addition, study the influence of symptoms, cannabis consumption, chlorpromazine doses, DUP and IQ in cognitive performance in patients, both in the total sample and divided by gender.

METHODS

70 first episode psychosis patients and 63 healthy controls (HC) participated in the study and were assessed with the MATRICS battery and the Vocabulary subtest of WAIS-IV. Symptoms in FEP patients were evaluated with the Emsley factors of the PANSS scale.

RESULTS

patients showed lower scores than controls in all cognitive domains studied. There were no significant differences between FEP men and FEP women, but we found gender differences in favour of women in processing speed, working memory and composite total scored domains in the HC group. Finally, symptoms and Chlorpromazine doses showed an influence on cognitive performance in the total FEP sample. When splitting the sample by gender, positive symptoms may be more detrimental to women's cognitive functioning, while disorganized symptoms may play the most important role in cognitive performance in men.

CONCLUSIONS

patients showed worse cognitive performance in all cognitive domains compared to healthy controls. In our FEP sample, gender does not seem to influence cognitive performance measured with the MATRICS. Severity of symptoms influences positively in cognitive performance. The dose of Chlorpromazine and symptoms are influential variables to be taken into account in cognition rehabilitation programs.

Social cognition and its relationship with sociodemographic, clinical, and psychosocial variables in first-episode psychosis

People with first episode of psychosis (FEP) show deficits in social cognition, which have been linked to several sociodemographic, clinical, and psychosocial variables. The aim of the present research was to study social cognition as a whole measure in people with FEP comparing it with a healthy control sample, to study gender differences, and to examine the relationship between sociodemographic, clinical, and psychosocial variables and social cognition in the onset of psychosis. A descriptive, cross-sectional study was performed. The study sample consisted of 63 people (18 females; 45 males) with a diagnosis of FEP and a healthy control group (78 participants: 38 females; 40 males). All the participants were assessed with the social cognitive domain of the MATRICS Consensus Cognitive Battery (MCCB) and several questionnaires related to studied variables. Our results indicated that compared with healthy controls, people with FEP showed social cognition deficits. Furthermore, premorbid IQ was the most relevant variable in social cognition performance in FEP sample. The findings of the present research may be taken into account in clinical practice to improve the intervention with people with FEP.

Association between anti-thyroid antibodies and negative symptoms in early psychosis

AIM

In the current cross-sectional study, we aimed to explore whether thyroid function or thyroid autoimmunity are associated with psychopathological symptoms and social functioning in patients with early psychosis. We hypothesized that psychopathological severity is greater in those patients with positive thyroid autoimmunity.

METHODS

We studied 70 outpatients with early psychosis (<3 years of illness) and 37 healthy subjects. Psychopathological symptoms (positive, negative, disorganized, excited and depressive) and social functioning were assessed. Thyroid autoimmunity (antibodies against thyroid peroxidase [TPO-Abs] and thyroglobulin [TG-Abs]) and thyroid function (thyroid-stimulating hormone [TSH] and free thyroxin [FT4]) were determined. Associations of thyroid variables and psychometric measures were assessed with Spearman's correlations. Logistic regression was performed to explore the association between psychopathological symptoms and positive anti-thyroidal antibodies while adjusting for covariates.

RESULTS

When compared to patients without thyroid antibodies, those with positive thyroid antibodies had more negative symptoms and poorer function (P < .05). Titres of TPO-Abs were significantly correlated with negative and depressive PANSS domains and poorer functioning. TG-Abs were also associated with poorer functioning but not with psychopathological symptoms. TSH and FT4 concentrations were not associated with clinical symptoms. In the logistic regression analysis adjusted for age, gender, antipsychotic treatment, lithium, TSH and FT4 concentrations, negative symptoms were associated with thyroid autoimmunity (OR = 1.2, P = .019).

CONCLUSIONS

Our study suggests that anti-thyroid antibodies are associated with a more severe phenotype with increased negative symptoms and poorer functioning in early psychotic patients. Since causality cannot be inferred with cross-sectional data, future longitudinal studies are needed to overcome this limitation.

Glycated Haemoglobin Is Associated With Poorer Cognitive Performance in Patients With Recent-Onset Psychosis

BACKGROUND

Glucose abnormalities and cognitive alterations are present before the onset of schizophrenia. We aimed to study whether glucose metabolism parameters are associated with cognitive functioning in recent-onset psychosis (ROP) patients while adjusting for hypothalamic-pituitary adrenal (HPA) axis measures.

METHODS

Sixty ROP outpatients and 50 healthy subjects (HS) were studied. Cognitive function was assessed with the MATRICS Consensus Cognitive Battery. Glycated haemoglobin (HbA1_c), glucose, insulin, and C-peptide levels were determined in plasma. The HOMA-insulin resistance index was calculated. Salivary samples were obtained at home on another day to assess the cortisol awakening response and cortisol levels during the day. Univariate analyses were conducted to explore the association between glucose metabolism parameters and cognitive tasks. For those parameters that were more clearly associated with the cognitive outcome, multiple linear regression analyses were conducted to adjust for covariates. Each cognitive task was considered the dependent variable. Covariates were age, sex, education level, diagnosis, antipsychotic and benzodiazepine treatment, body mass index (BMI), smoking, and HPA axis measures. Potential interactions between diagnosis and glucose parameters were tested.

RESULTS

There were no significant differences in HPA axis measures or glucose parameters, with the exception of C-peptide (that was higher in ROP patients), between groups. ROP patients had a lower performance than HS in all cognitive tasks (p < 0.01 for all tasks). Of all glucose metabolism parameters, HbA1c levels were more clearly associated with cognitive impairment in cognitive tasks dealing with executive functions and visual memory in both ROP patients and HS. Multivariate analyses found a significant negative association between HbA1c and cognitive functioning in five cognitive tasks dealing with executive functions, visual memory and attention/vigilance (a ROP diagnosis by HbA1_c negative interaction was found in this latter cognitive domain, suggesting that HBA1_c levels are associated with impaired attention only in ROP patients).

CONCLUSIONS

Our study found that HbA1_c was negatively associated with cognitive functioning in both ROP patients and HS in tasks dealing with executive functions and visual memory. In ROP patients, HbA1_c was also associated with impaired attention. These results were independent of BMI and measures of HPA axis activity.

Free Thyroxine Concentrations Moderate the Response to a Cognitive Remediation Therapy in People With Early Psychosis: A Pilot Randomized Clinical Trial

INTRODUCTION

Cognitive deficits are a cause of functional disability in psychotic disorders. Cognitive remediation therapy (CRT) might be applied to improve these deficits. We conducted a pilot study to explore whether thyroid hormones might predict the response to CRT in patients with recent-onset psychosis (ROP).

METHODS

Twenty-eight stable ROP outpatients (9 women) were randomized to receive computerized CRT (N=14) or treatment as usual (TAU) (N=14), over three months. Both cognitive and thyroid functions were assessed at the baseline and after those three months to all patients. A full cognitive battery (CANTAB) was administered before and after the treatment. Serum levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured. FT4 concentrations were recoded into a dichotomic variable (FT4 group) based on the median of the sample (1.2 ng/dL). Data were analyzed on an intention-to-treat basis with linear mixed models. Afterwards, we offered CRT to all participants from the TAU group and seven enrolled CRT, reassessing them when finished. Secondary analyses were repeated in a sample of 14 participants who completed the CRT (either from the beginning or after the TAU period) and attended at least one third of the sessions.

RESULTS

The linear mixed models showed a significant time x CRT x FT4 group effect in two cognitive tasks dealing with executive functions and sustained attention (participants with higher FT4 concentrations worsened executive functions but improved sustained attention after CRT). In the secondary analysis including all patients assigned to CRT, higher FT4 concentrations were associated with a poorer response in verbal memory but a better response in spatial working memory.

CONCLUSIONS

Free thyroxine concentrations moderate the response to a CRT in patients with early psychosis.

Behavior in dogs with spontaneous hypothyroidism during treatment with levothyroxine

Background

Thyroid hormone supplementation anecdotally has been described as a valid treatment option for dogs with aggression‐related problems. However, prospective, controlled, and blinded trials evaluating behavior and neurohormonal status in hypothyroid dogs during treatment with levothyroxine are lacking.

Objective

Levothyroxine supplementation will have a significant influence on the behavior and neurohormonal status of dogs with spontaneous hypothyroidism.

Animals

Twenty client‐owned dogs diagnosed with spontaneous hypothyroidism.

Methods

This prospective study was to evaluate the behavior of dogs, which was screened at initial presentation, and after 6 weeks, and 6 months of treatment with levothyroxine (starting dosage 10 μg/kg PO q12h) using the standardized Canine Behavioral Assessment and Research Questionnaire (C‐BARQ). At each time period, circulating serotonin and prolactin (PRL) concentrations were evaluated using a commercially validated ELISA kit and heterologous radioimmunoassay, respectively.

Results

After 6 weeks of thyroid hormone supplementation, C‐BARQ scores demonstrated a significant increase in activity of hypothyroid dogs (P < .01). No significant change in any of the behavioral signs was observed after 6 months of treatment. No significant difference in circulating concentrations of serotonin (P > .99 and P = .46) and PRL (P = .99 and P = .37) were noted between the 6‐week and 6‐month periods compared with baseline.

Conclusions and Clinical Importance

The results of this study indicate increased activity of hypothyroid dogs after 6 weeks of thyroid hormone supplementation. None of the hypothyroid dogs in this cohort showed a significant change in any of the evaluated behavioral signs and neurohormonal status after 6 months of thyroid hormone supplementation.

Gland New Psychosis: New Onset Adult Psychosis with Suicidal Ideation and Attempt in the Setting of Thyroid Storm

We present a case of new onset psychosis in the setting of thyroid storm in a woman with no previous psychiatric history. The patient presented with ongoing suicidal ideation, a suicide attempt that was interrupted by her husband, and audio and visual hallucinations. The patient was placed on a psychiatric hold and treated for thyrotoxicosis as well as psychosis. Treatment of the thyroid hormone overload resulted in a rapid resolution of her symptoms; she was discharged in excellent condition, and she has had no repeat hallucinations or self-injury ideation or attempts since. Although rare, thyrotoxicosis is a potentially life-threatening cause of psychiatric illness and should always be kept on the differential diagnosis for a patient with a first episode of psychosis. This case highlights how thyroid storm physiology, beyond its well-studied hemodynamic and metabolic instability, can be potentially fatal due to psychiatric sequelae. It also highlights the crucial role of a thorough history and physical exam in all patients.

A Role for the Transcription Factor Nk2 Homeobox 1 in Schizophrenia: Convergent Evidence from Animal and Human Studies

Schizophrenia is a highly heritable disorder with diverse mental and somatic symptoms. The molecular mechanisms leading from genes to disease pathology in schizophrenia remain largely unknown. Genome-wide association studies (GWASs) have shown that common single-nucleotide polymorphisms associated with specific diseases are enriched in the recognition sequences of transcription factors that regulate physiological processes relevant to the disease. We have used a “bottom-up” approach and tracked a developmental trajectory from embryology to physiological processes and behavior and recognized that the transcription factor NK2 homeobox 1 (NKX2-1) possesses properties of particular interest for schizophrenia. NKX2-1 is selectively expressed from prenatal development to adulthood in the brain, thyroid gland, parathyroid gland, lungs, skin, and enteric ganglia, and has key functions at the interface of the brain, the endocrine-, and the immune system. In the developing brain, NKX2-1-expressing progenitor cells differentiate into distinct subclasses of forebrain GABAergic and cholinergic neurons, astrocytes, and oligodendrocytes. The transcription factor is highly expressed in mature limbic circuits related to context-dependent goal-directed patterns of behavior, social interaction and reproduction, fear responses, responses to light, and other homeostatic processes. It is essential for development and mature function of the thyroid gland and the respiratory system, and is involved in calcium metabolism and immune responses. NKX2-1 interacts with a number of genes identified as susceptibility genes for schizophrenia. We suggest that NKX2-1 may lie at the core of several dose dependent pathways that are dysregulated in schizophrenia. We correlate the symptoms seen in schizophrenia with the temporal and spatial activities of NKX2-1 in order to highlight promising future research areas.