Publications by authors named "Martin Melchers"

Background: The serotonergic and noradrenergic systems have a strong impact on several affective disorders and are key targets for psychopharmacological therapy. With respect to pathogenesis, there is a growing body of evidence showing an influence of a promoter repeat polymorphism (MAOA-uVNTR) altering the expression rate of monoamine oxidase A. However, only a few studies investigate its influence on depression with only 2 of them considering the moderating effects of life stress.

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Recent studies have yielded initial evidence for an association between Internet Use Disorder (IUD), empathy, and life satisfaction. In the present study we sought to replicate these previous findings, and then to extend this research by also examining the relationship between empathy, life satisfaction, and the related phenomenon of Smartphone Use Disorder (SUD). The present study included independent samples from China ( = 612, 162 females) and Germany ( = 304, 207 females), with the same set of questionnaires administered to both samples.

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There is increasing evidence for associations between polymorphisms of the oxytocin receptor (OXTR) gene and autism spectrum disorder, but to date no study has established links with autistic traits in healthy subjects and potential cultural differences. The present research firstly investigated associations between three widely studied OXTR SNPs and autistic and empathic traits (rs53576 (G/A); rs2254298 (G/A); rs2268498 (T/C)) in two independent studies on male and female Caucasian (n = 537) and Chinese students (n = 280). Autistic and empathic traits were measured in all subjects in the two independent groups using the Autism -Spectrum Quotient (AQ) and the Interpersonal Reactivity Index (IRI) respectively, together with their sub-scales.

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Oxytocin is an important messenger in the brain that has been linked to a variety of social functions in pharmacological studies. Besides, functional genetic variations on the oxytocin receptor gene have been repeatedly associated with social processing and functioning. Despite this knowledge, there are very few studies investigating the mechanisms that may explain the link between oxytocin and social functions.

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Introduction: Emotion regulation is an important everyday-life skill to reduce harm and stress. Consequently, research shows associations between psychopathologies and emotional dysregulation. The serotonin transporter polymorphism (5-HTTLPR) has repeatedly been associated to phenotypes and syndromes related to emotional dysregulation.

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The brain is an intricate network, not only structurally but also functionally. On the functional level, connectivity in the brain is organized in separable yet interacting networks that support information processing by maintaining a ready state, even in the absence of external stimulation. It has been hypothesized that an insular-opercular network underlies the processing of emotionally salient information and that individual differences in functional connectivity within this network correspond to individual differences in trait anxiety.

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Empathy is an important human ability associated with successful social interaction. It is currently unclear how to optimally measure individual differences in empathic processing. Although the Big Five model of personality is an effective model to explain individual differences in human experience and behavior, its relation to measures of empathy is currently not well understood.

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Stress-related affective disorders have been identified as a core health problem of the twenty-first century. In the endeavor to identify vulnerability factors, personality has been discussed as a major factor explaining and predicting disorders like depression or burnout. An unsolved question is whether there are specific personality factors allowing differentiation of burnout from depression.

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As empathy has not been investigated in the context of problematic use of the Internet, we conducted a study to test for a potential link. In samples from China (N=438) and Germany (N=202), two self-report measures for empathic behavior and one self-report measure for problematic Internet use (PIU) were administered in adolescents/students. Across both cultures lower empathy was associated with more PIU.

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Social perception is an important prerequisite for successful social interaction, because it helps to gain information about behaviors, thoughts, and feelings of interaction partners. Previous pharmacological studies have emphasized the relevance of the oxytocin system for social perception abilities, while knowledge on genetic contributions is still scarce. In the endeavor to fill this gap in the literature, the current study searches for associations between participants' social perception abilities as measured by the interpersonal perception task (IPT) and the rs2268498 polymorphism on the OXTR-gene, which has repeatedly been linked to processes relevant to social functioning.

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Background: Vicarious embarrassment (VE) is an emotion triggered by the observation of others' pratfalls or social norm violations. Several explanatory approaches have been suggested to explain the source of this phenomenon, including perspective taking abilities or ingroup identification. Knowledge about its biological bases, however, is scarce.

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Introduction: Research on empathy has a long tradition in clinical research, as deficits in empathy have been found in many mental disorders. Over decades, a large amount of measures for empathy have been developed, but in many cases these have not been analysed with respect to validity. Therefore, this paper aims to relate various assessment methods for empathy, schizotypy and autistic traits to gain knowledge on their convergent and discriminant validity.

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The ability to understand thoughts and feelings of another person is an important prerequisite for successful social interaction. One part of this ability is the recognition of emotions in the face of the counterpart. Knowledge on genetic contributions to emotion recognition is still scarce.

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The investigation of the interaction of genes and environment in the context of mental health and personality yields important new insights for a better understanding of human nature. Both antenatal and postnatal environmental factors have been considered as potential modulators of genetic activity. Antenatally, especially smoking or alcohol drinking habits of the mother dramatically influence the health of the child during pregnancy and even later on in life.

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Chronic stress and related disruption of hypothalamic-pituitary-adrenal axis reactivity is a known risk factor for depression. Besides its effects on glucocorticoids, stress also impacts the cholinergic system. Therefore, the interaction of two polymorphisms, one on the cholinergic CHRNA4 receptor gene and one on the glucocorticoid receptor gene (NR3C1), on depression was investigated.

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Starting from natural product podophyllotoxin 1 substituted heterolignans were identified with promising insecticidal in vivo activity. The impact of substitution in each segment of the core structure was investigated in a detailed SAR study, and variation of substituents in both aromatic moieties afforded derivatives 5 and 43 with broad insecticidal activity against lepidopteran and coleopteran species. In vitro measurements supported by modeling studies indicate that heterolignans 3-134 act as tubuline polymerization inhibitors interacting with the colchicine-binding site.

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