Raphael Hirtz

• PD MD/PhD
• Senior Researcher at HELIOS Universitätsklinikum Wuppertal

Background Preexisting epidemiological studies suggest that early pubertal development in males is associated with externalizing (e.g. conduct problems, risky behavior, and aggression) and internalizing (e.g. depression and anxiety) traits and disorders. However, due to problems inherent to observational studies, especially of residual confounding,...

Very preterm infants are at higher risk of long‐term neurodevelopmental and psychiatric impairments, including anxiety. Prematurity is also linked to altered programming of the hypothalamus–pituitary–adrenal (HPA) axis, associated with stress‐related diseases. The cortisol awakening response (CAR), marked by a rapid cortisol increase after waking,...

Background Bardet–Biedl syndrome (BBS) is a rare autosomal-recessive ciliopathy with pathogenic variants in 26 BBS genes. It affects multiple organs, including the kidney and liver, with varying degrees regarding extent and time of first manifestation. Structural renal anomalies are an early feature and end-stage kidney disease (ESKD) cumulates to...

Individuals with ultrarare disorders pose a structural challenge for healthcare systems since expert clinical knowledge is required to establish diagnoses. In TRANSLATE NAMSE, a 3-year prospective study, we evaluated a novel diagnostic concept based on multidisciplinary expertise in Germany. Here we present the systematic investigation of the pheno...

Preexisting epidemiological studies suggest that early pubertal development in males is associated with externalizing (e.g., conduct problems, risky behavior, and aggression) and internalizing (e.g., depression and anxiety) traits and disorders. However, due to problems inherent to observational studies, especially of reverse causation and residual...

The higher prevalence of attention-deficit/hyperactivity disorder (ADHD) in males raises the question of whether testosterone is implicated in ADHD risk. However, cross-sectional studies did not identify an association between ADHD and testosterone levels. Mendelian randomization (MR) studies can overcome limitations inherent to association studies...

Context Reliable reference values for thyroid ultrasound measurements are essential to effectively guide individual diagnostics and direct population-level health care measures, such as iodine fortification programs. However, the latest reference values for total thyroid volume (Tvol) provided by the World Health Organization (WHO) in 2004 only app...

Background In males, the relationship between pubertal timing and depression is understudied and less consistent than in females, likely for reasons of unmeasured confounding. To clarify this relationship, a combined epidemiological and genetic approach was chosen to exploit the methodological advantages of both approaches. Methods Data from 2026...

Background Bardet-Biedl syndrome (BBS) is a rare autosomal-recessive ciliopathy with pathogenic variants in at least 26 BBS genes. It affects multiple organs including kidney and liver, however, organ involvement differs widely regarding extent and time of first manifestation. Structural renal anomalies are an early feature with a frequency of > 50...

Context Reliable reference values for thyroid ultrasound measurements are essential to effectively guide individual diagnostics and direct health care measures at the population level, such as iodine fortification programs. However, the latest reference values for total thyroid volume (Tvol) provided by the WHO in 2004 only apply to the 6 to 12-yea...

The higher prevalence of attention-deficit/hyperactivity disorder (ADHD) in males raises the question of whether testosterone is implicated in ADHD risk. However, cross-sectional studies did not identify an association between ADHD and testosterone levels. Mendelian randomization (MR) studies can overcome limitations inherent to association studies...

Background The present study evaluates personality traits in adult patients with cystic fibrosis (CF) and correlates these results with health-related quality of life (HRQoL) and other clinical parameters indicative of disease severity. Methods Seventy adults completed the Cystic Fibrosis Questionnaire-Revised (CFQ-R 14+), a CF-specific measure of...

Background: In males, the relationship between pubertal timing and depression is understudied and less consistent than in females, likely for reasons of unmeasured confounding. To clarify this relationship, a combined epidemiological and genetic approach was chosen to exploit the methodological advantages of both approaches. Methods: Data from 2,02...

Introduction: Recently, cystic fibrosis transmembrane regulator modulator therapy with elexacaftor/tezacaftor/ivacaftor has become available for children with cystic fibrosis (CF) carrying at least one F508del mutation. Objective: To assess the intermediate term effects of elexacaftor/tezacaftor/ivacaftor in children with cystic fibrosis in a real-...

Most individuals with rare diseases initially consult their primary care physician. For a subset of rare diseases, efficient diagnostic pathways are available. However, ultra-rare diseases often require both expert clinical knowledge and comprehensive genetic diagnostics, which poses structural challenges for public healthcare systems. To address t...

Introduction The number of children with acute and chronic liver disease is rising. Moreover, liver involvement may be limited to subtle changes in organ texture especially in early childhood and some syndromic conditions, such as ciliopathies. Attenuation imaging coefficient (ATI), shear wave elastography (SWE), and dispersion (SWD) are emerging u...

Increased thermogenesis in brown adipose tissue might have an obesity-reducing effect in humans. In transgenic mice, depletion of genes involved in creatine metabolism results in disrupted thermogenic capacity and altered effects of high-fat feeding on body weight. Data analyses of a sex-stratified genome-wide association study (GWAS) for body mass...

Background: The present study evaluates personality traits in adult patients with cystic fibrosis (CF) and correlates these results with health-related quality of life (HRQoL) and other clinical parameters indicative of disease severity. Methods: Seventy adults completed the Cystic Fibrosis Questionnaire-Revised (CFQ-R +14), a CF-specific measure o...

Background Cough suppression assessed by embarrassment about coughing has been shown in adolescents with cystic fibrosis (CF) and negatively affects health-related quality of life (HRQoL) and clinical indicators of disease severity in adolescent females. However, whether cough suppression exists in adults has been studied as little as its effects o...

Context The timing of puberty, physical features of pubertal development, and hormones are closely intertwined but may also individually contribute to the risk for depression and depression severity. Additionally, their effects on mood may depend on depression severity, but previously this has only been studied in mostly subclinical depression. Me...

Background: While the relationship between subclinical hypothyroidism and major depressive disorder (MDD) has been studied in adults in cross-sectional and prospective population-based studies, this has not yet been done in adolescents. However, since thyroid function and MDD risk are subjected to maturational processes and ramifications of illnes...

A fair number of epidemiological studies suggest that age at menarche (AAM) is associated with depression, but the reported effect sizes are small, and there is evidence of residual confounding. Moreover, previous Mendelian randomization (MR) studies to avoid inferential problems inherent to epidemiological studies have provided mixed findings. To...

There is preliminary evidence that adrenal steroids other than cortisol may be valuable biomarkers for major depressive disorder (MDD). So far, studies have been conducted in adults only, and conclusions are limited, mainly due to small sample sizes. Therefore, the present study assessed whether adrenal steroids serve as biomarkers for adolescent M...

Background: Cough suppression assessed by embarrassment about coughing has been shown in adolescents with cystic fibrosis (CF) and negatively affects health-related quality of life (HRQoL) and clinical indicators of disease severity in adolescent females. However, whether cough suppression exists in adults has been studied as little as its effects...

Background: Cardiac auscultation is a core clinical skill taught in medical school. Due to contact restrictions during the SARS-CoV-2 pandemic, interaction with patients was very limited. Therefore, a peer-to-peer virtual case-based auscultation course via video conference was established. Methods: A randomized controlled cross-over study was co...

There is a distinct increase in the prevalence of depression with the onset of puberty. The role of peripubertal testosterone levels in boys in this context is insufficiently understood and may be modulated by a functional polymorphism of the androgen receptor gene (AR), a variable number of CAG repeats. Moreover, there is preliminary evidence that...

Zusammenfassung. Genetische Varianten beeinflussen die Gewichtsregulation und die Entwicklung von Essstörungen. Zunächst haben familienbasierte, sogenannte formalgenetische Studien den erblichen Anteil an der Gewichtsregulation und an der Ätiologie von Essstörungen beleuchtet. In einer Vielzahl von Studien zeigten sich sowohl für die Varianz des Kö...

In adults with major depressive disorder (MDD), a dysfunction between the hypothalamus-pituitary-adrenal (HPA) and the hypothalamus-pituitary-thyroid (HPT) axis has been shown, but the interaction of both axes has not yet been studied in adolescent major depressive disorder (MDD). Data from 273 adolescents diagnosed with MDD from two single center...

Objective: The aim of this study was to investigate the frequency of newly diagnosed type 1 diabetes without evidence of autoimmunity and the respective frequencies of ketoacidosis in children, adolescents, and young adults during the coronavirus disease 2019 (COVID-19) pandemic in Germany compared with the previous decade. Research design and me...

Objective To examine the effect of intrathecal application of nusinersen on the respiratory function in terms of vital capacity in pediatric patients with spinal muscular atrophy (SMA). SMA is characterized by on-going muscular atrophy and weakness that lead to respiratory insufficiency. In recent years therapy with nusinersen has been shown to imp...

Objective: The study was undertaken to determine the prevalence of subclinical and overt thyroid dysfunction as well as thyroid autoimmunity in depressed adolescents in comparison to the general pediatric population. Additionally, the relationship between parameters of thyroid function and Beck Depression Inventory-II (BDI-II) scores was examined....

Background: In adults, a significant impact of thyroid dysfunction and autoimmunity on health-related quality of life (HRQoL) and mental health is described. However, studies in children and adolescents are sparse, underpowered, and findings are ambiguous. Methods: Data from 759 German children and adolescents affected by thyroid disease [subclinic...

Polygenic factors are relevant for the genetic predispositions to the eating disorder anorexia nervosa (AN). The most recent genome-wide association study (GWAS) for AN comprised almost 17,000 patients with AN and controls. A total of eight genome-wide significant polygenic loci associated with AN have been identified. Each single polygenic locus m...

Purpose While observational studies revealed inverse associations between serum vitamin D levels [25(OH)D] and depression, randomized controlled trials (RCT) in children and adolescents are lacking. This RCT examined the effect of an untreated vitamin D deficiency compared to an immediate vitamin D3 supplementation on depression scores in children...

While there is a growing body of evidence regarding the behavioral and neurofunctional changes in response to the longitudinal delivery of transcranial direct current stimulation (tDCS), there is limited evidence regarding its structural effects. Therefore, the present study was intended to investigate the effect of repeatedly applied anodal tDCS o...

Transfer learning is an immanent feature of perceptual learning. Yet, despite the increasingly widespread application of transcranial direct current stimulation (tDCS) to study learning, transfer effects in response to tDCS have not been studied. Therefore, the present study investigated the transfer of tactile acuity evoked by repeatedly applied a...

We investigated the effect of repeated delivery of anodal transcranial direct current stimulation (tDCS) on somatosensory performance and long-term learning. Over the course of five days, tDCS was applied to the primary somatosensory cortex (S1) by means of neuronavigation employing magnetencephalography (MEG). Compared to its sham application, tDC...

Current findings suggest that confidence emerges only after decision making. However, the temporal and neural dynamics of the emergence of post-decision confidence-a metacognitive judgement-are not fully explored. To gain insight into the dynamics of post-decision confidence processing and to disentangle the processes underlying confidence judgemen...