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Dive into the research topics where Norbert Leygraf is active.

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Featured researches published by Norbert Leygraf.


Psychoneuroendocrinology | 2000

Neuroendocrine response to film-induced sexual arousal in men and women

Natalie G Exton; Trinh Chau Truong; Michael S. Exton; Sabine A Wingenfeld; Norbert Leygraf; Bernhard Saller; Uwe Hartmann; Manfred Schedlowski

The psychoneuroendocrine responses to sexual arousal have not been clearly established in humans. However, we have demonstrated previously that masturbation-induced orgasm stimulates cardiovascular activity and induces increases in catecholamines and prolactin in blood of both males and females. We presently investigated the role of orgasm in producing these effects. Therefore, in this study parallel analysis of prolactin, adrenaline, noradrenaline, and cortisol concentrations, together with cardiovascular variables of systolic/diastolic blood pressure and heart rate were undertaken during film-induced sexual arousal in nine healthy adult men and nine healthy adult women. Blood was drawn continuously via an indwelling cannula and connected tubing system passed through a mini-pump. In parallel, the cardiovascular parameters were recorded continuously via a computerised finger-cuff sensor. Subjective sexual arousal increased significantly in both men and women during the erotic film, with sexual arousal eliciting an increase in blood pressure in both males and females, and plasma noradrenaline in females only. In contrast, adrenaline, cortisol and prolactin levels were unaffected by sexual arousal. These data further consolidate the role of sympathetic activation in sexual arousal processes. Furthermore, they demonstrate that increases in plasma prolactin during sexual stimulation are orgasm-dependent, suggesting that prolactin may regulate a negative-feedback sexual-satiation mechanism.


NeuroImage | 2008

Functional brain correlates of heterosexual paedophilia.

Boris Schiffer; Thomas Paul; Elke R. Gizewski; Michael Forsting; Norbert Leygraf; Manfred Schedlowski; Tillmann H.C. Kruger

Although the neuronal mechanisms underlying normal sexual motivation and function have recently been examined, the alterations in brain function in deviant sexual behaviours such as paedophilia are largely unknown. The objective of this study was to identify paedophilia-specific functional networks implicated in sexual arousal. Therefore a consecutive sample of eight paedophile forensic inpatients, exclusively attracted to females, and 12 healthy age-matched heterosexual control participants from a comparable socioeconomic stratum participated in a visual sexual stimulation procedure during functional magnetic resonance imaging. The visual stimuli were sexually stimulating photographs and emotionally neutral photographs. Immediately after the imaging session subjective responses pertaining to sexual desire were recorded. Principally, the brain response of heterosexual paedophiles to heteropaedophilic stimuli was comparable to that of heterosexual males to heterosexual stimuli, including different limbic structures (amygdala, cingulate gyrus, and hippocampus), the substantia nigra, caudate nucleus, as well as the anterior cingulate cortex, different thalamic nuclei, and associative cortices. However, responses to visual sexual stimulation were found in the orbitofrontal cortex in healthy heterosexual males, but not in paedophiles, in whom abnormal activity in the dorsolateral prefrontal cortex was observed. Thus, in line with clinical observations and neuropsychological studies, it seems that central processing of sexual stimuli in heterosexual paedophiles may be altered by a disturbance in the prefrontal networks, which, as has already been hypothesized, may be associated with stimulus-controlled behaviours, such as sexual compulsive behaviours. Moreover, these findings may suggest a dysfunction (in the functional and effective connectivity) at the cognitive stage of sexual arousal processing.


Archives of General Psychiatry | 2011

Disentangling Structural Brain Alterations Associated With Violent Behavior From Those Associated With Substance Use Disorders

Boris Schiffer; Bernhard W. Müller; Norbert Scherbaum; Sheilagh Hodgins; Michael Forsting; Jens Wiltfang; Elke R. Gizewski; Norbert Leygraf

CONTEXT Studies aimed at identifying structural brain alterations associated with persistent violent behavior or psychopathy have not adequately accounted for a lifetime history of substance misuse. Thus, alterations in gray matter (GM) volume that have been reported to be correlates of violent behavior and/or psychopathy may instead be related to lifelong substance use disorders (SUDs). OBJECTIVE To identify alterations in GM volume associated with violent behavior and those associated with lifelong SUDs. DESIGN Cross-sectional study. SETTING Participants were recruited from penitentiaries, forensic hospitals, psychiatric outpatient services, and communities in Germany. Structural magnetic resonance imaging was performed at a university hospital. PARTICIPANTS Four groups of men were compared: 12 men with SUDs who exhibited violent behavior (hereafter referred to as violent offenders), 12 violent offenders without SUDs, 13 men with SUDs who did not exhibit violent behavior (hereafter referred to as nonoffenders), and 14 nonoffenders without SUDs. MAIN OUTCOME MEASURES Voxel-based morphometry was used to analyze high-resolution magnetic resonance imaging scans. Assessments of mental disorders, psychopathy (using the Psychopathy Checklist-Screening Version), aggressive behavior, and impulsivity were conducted by trained clinicians. RESULTS Compared with nonoffenders, violent offenders presented with a larger GM volume in the amygdala bilaterally, the left nucleus accumbens, and the right caudate head and with less GM volume in the left insula. Men with SUDs exhibited a smaller GM volume in the orbitofrontal cortex, ventromedial prefrontal cortex, and premotor cortex than did men without SUDs. Regression analyses indicated that the alterations in GM volume that distinguished the violent offenders from nonoffenders were associated with psychopathy scores and scores for lifelong aggressive behavior. The GM volumes of the orbitofrontal cortex and prefrontal cortex that distinguished the men with SUDs from the men without SUDs were correlated with scores for response inhibition. CONCLUSIONS These findings suggest that a greater GM volume in the mesolimbic reward system may be associated with violent behavior and that reduced GM volumes in the prefrontal cortex, orbitofrontal cortex, and premotor area characterize men with SUDs.


Brain | 2010

Impulsivity-related brain volume deficits in schizophrenia-addiction comorbidity

Boris Schiffer; Bernhard W. Müller; Norbert Scherbaum; Michael Forsting; Jens Wiltfang; Norbert Leygraf; Elke R. Gizewski

Despite a high prevalence of schizophrenia patients with comorbid substance abuse, little is known about possible impacts on the brain. Hence, our goal was to determine whether addicted and non-addicted schizophrenic patients suffer from different brain deficits. We were especially interested to determine if grey matter volumes were affected by impulsivity. We hypothesized that (comorbid) substance abuse would be associated with enhanced impulsivity and that this enhanced impulsivity would be related to grey matter volume deficits in prefrontal areas. We employed a voxel-based morphometry approach as well as neuropsychological assessment of executive functions and trait impulsivity in 51 participants (age range 23-55). The schizophrenia group comprised 24 patients (12 patients with paranoid schizophrenia and 12 with additional comorbid substance use disorders). The comparison group comprised 27 non-schizophrenic individuals, matched by age and education (14 healthy individuals and 13 patients with substance use disorders). Total grey matter volume deficits were found in all patient groups as compared with healthy controls but were largest (~8%) in both addicted groups. While grey matter volume losses in lateral orbitofrontal and temporal regions were affected by schizophrenia, volume decreases of the medial orbitofrontal, anterior cingulate and frontopolar cortex were associated with addiction. Compared with non-addicted schizophrenics, comorbid patients showed significant volume decreases in anterior cingulate, frontopolar and superior parietal regions. Additionally, they showed an increased non-planning impulsivity that was negatively related to grey matter volumes in the same regions, except for parietal ones. The present study indicates severe grey matter volume and functional executive deficits in schizophrenia, which were only partially exacerbated by comorbid addiction. However, the relationship between non-planning impulsivity and anterior cingulate and frontopolar grey matter volumes points to a specific structure-function relationship that seems to be impaired in schizophrenia-addiction comorbidity.


Addiction Biology | 2013

The impact of alcohol dependence on social brain function.

Elke R. Gizewski; Bernhard W. Müller; Norbert Scherbaum; Bodo Lieb; Michael Forsting; Jens Wiltfang; Norbert Leygraf; Boris Schiffer

The impact of alcoholism (ALC) or alcohol dependence on the neural mechanisms underlying cognitive and affective empathy (i.e. the different routes to understanding other peoples minds) in schizophrenic patients and non‐schizophrenic subjects is still poorly understood. We therefore aimed at determining the extent to which the ability to infer other peoples mental states and underlying neural mechanisms were affected by ALC. We examined 48 men, who suffered either from ALC, schizophrenia, both disorders or none of these disorders, using functional magnetic resonance imaging while performing on a mind reading task that involves both cognitive and affective aspects of empathy. Using voxel‐based morphometry, we additionally examined whether between‐group differences in functional activity were associated with deficits in brain structural integrity. During mental state attribution, all clinical groups as compared with healthy controls exhibited poor performance as well as reduced right‐hemispheric insular function with the highest error rate and insular dysfunction seen in the schizophrenic patients without ALC. Accordingly, both behavioral performance and insular functioning revealed schizophrenia × ALC interaction effects. In addition, schizophrenic patients relative to non‐schizophrenic subjects (regardless of ALC) exhibited deficits in structural integrity and task‐related recruitment of the left ventrolateral prefrontal cortex (vlPFC). Our data suggest that ALC‐related impairment in the ability to infer other peoples mental states is limited to insular dysfunction and thus deficits in affective empathy. By contrast, mentalizing in schizophrenia (regardless of ALC) may be associated with insular dysfunction as well as a combination of structural and functional deficits in the left vlPFC.


Schizophrenia Bulletin | 2013

Structural Brain Alterations Associated With Schizophrenia Preceded by Conduct Disorder: A Common and Distinct Subtype of Schizophrenia?

Boris Schiffer; Norbert Leygraf; Bernhard W. Müller; Norbert Scherbaum; Michael Forsting; Jens Wiltfang; Elke R. Gizewski; Sheilagh Hodgins

Conduct disorder (CD) prior to age 15 is a precursor of schizophrenia in a minority of cases and is associated with violent behavior through adulthood, after taking account of substance misuse. The present study used structural magnetic imaging to examine gray matter (GM) volumes among 27 men with schizophrenia preceded by CD (SZ+CD), 23 men with schizophrenia but without CD (SZ-CD), 27 men with CD only (CD), and 25 healthy (H) men. The groups with schizophrenia were similar in terms of age of onset and duration of illness, levels of psychotic symptoms, and medication. The 2 groups with CD were similar as to number of CD symptoms, lifelong aggressive behavior, and number of criminal convictions. Men with SZ+CD, relative to those with SZ-CD, displayed (1) increased GM volumes in the hypothalamus, the left putamen, the right cuneus/precuneus, and the right inferior parietal cortex after controlling for age, alcohol, and drug misuse and (2) decreased GM volumes in the inferior frontal region. Men with SZ+CD (relative to the SZ-CD group) and CD (relative to the H group) displayed increased GM volumes of the hypothalamus and the inferior and superior parietal lobes, which were not associated with substance misuse. Aggressive behavior, both prior to age 15 and lifetime tendency, was positively correlated with the GM volume of the hypothalamus. Thus, among males, SZ+CD represents a distinct subtype of schizophrenia. Although differences in behavior emerge in childhood and remain stable through adulthood, further research is needed to determine whether the differences in GM volumes result from abnormal neural development distinct from that of other males developing schizophrenia.


Psychiatry Research-neuroimaging | 2014

Neural mechanisms underlying cognitive control of men with lifelong antisocial behavior

Boris Schiffer; Christina Pawliczek; Bernhard Mu Ller; Michael Forsting; Elke R. Gizewski; Norbert Leygraf; Sheilagh Hodgins

Results of meta-analyses suggested subtle deficits in cognitive control among antisocial individuals. Because almost all studies focused on children with conduct problems or adult psychopaths, however, little is known about cognitive control mechanisms among the majority of persistent violent offenders who present an antisocial personality disorder (ASPD). The present study aimed to determine whether offenders with ASPD, relative to non-offenders, display dysfunction in the neural mechanisms underlying cognitive control and to assess the extent to which these dysfunctions are associated with psychopathic traits and trait impulsivity. Participants comprised 21 violent offenders and 23 non-offenders who underwent event-related functional magnetic resonance imaging while performing a non-verbal Stroop task. The offenders, relative to the non-offenders, exhibited reduced response time interference and a different pattern of conflict- and error-related activity in brain areas involved in cognitive control, attention, language, and emotion processing, that is, the anterior cingulate, dorsolateral prefrontal, superior temporal and postcentral cortices, putamen, thalamus, and amygdala. Moreover, between-group differences in behavioural and neural responses revealed associations with core features of psychopathy and attentional impulsivity. Thus, the results of the present study confirmed the hypothesis that offenders with ASPD display alterations in the neural mechanisms underlying cognitive control and that those alterations relate, at least in part, to personality characteristics.


The Canadian Journal of Psychiatry | 2003

Acute neuroendocrine response to sexual stimulation in sexual offenders.

Philip Haake; Manfred Schedlowski; Michael S. Exton; Christoph Giepen; Uwe Hartmann; Michael Osterheider; Martin Flesch; Onno E. Janssen; Norbert Leygraf; Tillmann H.C. Kruger

Background: Several pharmacotherapeutic approaches have confirmed the influence of neuroendocrine parameters on sexual desire, function, and fantasies in men; however, the relevance of acute neuroendocrine changes in mediating heightened sexual drive remains unknown. We recently demonstrated that plasma prolactin substantially increases following orgasm in healthy men, suggesting a feedback mechanism for peripheral prolactin in the control of acute sexual arousal. Because prolactin appears to play a regulatory role in acute sexual drive, we initiated this study to see whether sexual offenders with a high sexual drive have a different neuroendocrine response to sexual arousal. This study compares the prolactin response to orgasm of sexual offenders with high sexual drive and that of healthy subjects with average sexual drive. Methods: From a subject pool of 150 inpatients held because of sexual crimes, we recruited 10 volunteers, based on their high sexual drive according to an intensive, semistructured clinical interview. We defined sexual drive by a short refractory period and strong sexualization, or a high frequency of sexual stimulation. We analyzed the acute psychoneuroendocrine response to sexual arousal and orgasm continuously before, during, and after masturbation-induced orgasm in patients and control subjects. Results: Sexual offenders demonstrated higher sexual desire (P < 0.001) and function (P < 0.001) and a more positively perceived refractory period (P < 0.05). Both groups displayed a prolonged, significant increase in prolactin plasma levels after orgasm (P < 0.001). Sexual offenders did not differ from control subjects in neuroendocrine response to sexual arousal and orgasm. Conclusions: These data demonstrate that sexual offenders with a high sexual drive do not differ from control subjects in the postorgasmic neuroendocrine response, particularly in prolactin release. This study confirms that factors other than peripheral hormones influence deviant sexual behaviour.


Nervenarzt | 1999

Drogenabhängige Straftäter im Maßregelvollzug Ergebnisse einer Querschnittserhebung

Dieter Seifert; Norbert Leygraf

ZusammenfassungDie Klientel der drogen- und/oder medikamentenabhängigen Straftäter im Maßregelvollzug (gemäߧ 64 StGB) hat sich gegenüber der Situation Mitte der 80er Jahre erkennbar geändert. Basierend auf den Daten einer Querschnittserhebung aus Nordrhein-Westfalen sind diagnostisch nun überwiegend polytoxikomane Entwicklungen zu beschreiben, wobei Opiate weiterhin die bedeutende Stellung innerhalb des Drogenspektrums einnehmen. Der Schweregrad der zur Unterbringung geführten Straftaten (Einweisungsdelikte) hat zugenommen. Waren in den 80er Jahren vorwiegend Straftaten gegen das Betäubungsmittelgesetz (BtMG) beobachtet worden, so stellt heute der Raub das „klassische” Einweisungsdelikt dar. Das Problem der Definition von „Fehleinweisung” wird mehrdimensional betrachtet.SummaryIn comparison to the middle of the 80th, the group of patients who are addicted to legal and illegal drugs and are treated in special forensic hospitals, has significantly changed. Polyvalent dependence is the predominant diagnosis. There has been an increase in violence of index delinquency. In the middle of the 80th, most of the patients were committed because of criminal offences against the BtMG (German law to sentence drug abusers). Today, robbery turns out to be the „classical” index delinquency. The problem of defining „false admission” to a forensic hospital has to be considered in a multidimensional way.


Archive | 1992

Prognosegutachten. Klinisch-psychiatrische und psychologische Beurteilungsmöglichkeiten der Kriminalprognose

Norbert Leygraf; Sabine Nowara

Die Diskussion uber Moglichkeiten und Grenzen individueller Legal- bzw. Kriminalprognosen steht seit Jahrzehnten im Brennpunkt des kriminologischen Interesses. Als umstritten gilt insbesondere die Frage, inwieweit Psychiater und Psychologen aufgrund eines speziellen „Expertenwissens“zu solchen Verhaltensvorhersagen in der Lage sind (Steadman 1983; Rasch 1984).

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Boris Schiffer

University of Duisburg-Essen

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Michael Forsting

University of Duisburg-Essen

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Elke R. Gizewski

Innsbruck Medical University

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Manfred Schedlowski

University of Duisburg-Essen

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Bernhard W. Müller

University of Duisburg-Essen

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Jens Wiltfang

University of Duisburg-Essen

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Norbert Schalast

University of Duisburg-Essen

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Norbert Scherbaum

University of Duisburg-Essen

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