Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
109
result(s) for
"Borgwardt, Stefan J."
Sort by:
Direct comparison of the acute subjective, emotional, autonomic, and endocrine effects of MDMA, methylphenidate, and modafinil in healthy subjects
by
Liechti, Matthias E.
,
Dolder, Patrick C.
,
Schmid, Yasmin
in
Acute effects
,
Adult
,
Adverse drug reactions
2018
Rationale
3,4-Methylenedioxymethamphetamine (MDMA) is used recreationally and investigated as an adjunct to psychotherapy. Methylphenidate and modafinil are psychostimulants that are used to treat attention-deficit/hyperactivity disorder and narcolepsy, respectively, but they are also misused as cognitive enhancers. Little is known about differences in the acute effects of equally cardiostimulant doses of these stimulant-type substances compared directly within the same subjects.
Methods
We investigated the acute autonomic, subjective, endocrine, and emotional effects of single doses of MDMA (125 mg), methylphenidate (60 mg), modafinil (600 mg), and placebo in a double-blind, cross-over study in 24 healthy participants. Acute drug effects were tested using psychometric scales, the Facial Emotion Recognition Task (FERT), and the Sexual Arousal and Desire Inventory (SADI).
Results
All active drugs produced comparable hemodynamic and adverse effects. MDMA produced greater increases in pupil dilation, subjective good drug effects, drug liking, happiness, trust, well-being, and alterations in consciousness than methylphenidate or modafinil. Only MDMA reduced subjective anxiety and impaired fear recognition and led to misclassifications of emotions as happy on the FERT. On the SADI, only MDMA produced sexual arousal-like effects. Only MDMA produced marked increases in cortisol, prolactin, and oxytocin. In contrast to MDMA, methylphenidate increased subjective anxiety, and methylphenidate and modafinil increased misclassifications of emotions as angry on the FERT. Modafinil had no significant subjective drug effects but significant sympathomimetic and adverse effects.
Conclusions
MDMA induced subjective, emotional, sexual, and endocrine effects that were clearly distinct from those of methylphenidate and modafinil at the doses used.
Journal Article
Modulation of Auditory and Visual Processing by Delta-9-Tetrahydrocannabinol and Cannabidiol: an fMRI Study
by
Seal, Marc L
,
Crippa, Jose A
,
Zuardi, Antonio W
in
631/1647/245/1627
,
631/378/2613
,
631/378/2619
2011
Although the effects of cannabis on perception are well documented, little is known about their neural basis or how these may contribute to the formation of psychotic symptoms. We used functional magnetic resonance imaging (fMRI) to assess the effects of Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) during visual and auditory processing in healthy volunteers. In total, 14 healthy volunteers were scanned on three occasions. Identical 10 mg THC, 600 mg CBD, and placebo capsules were allocated in a balanced double-blinded pseudo-randomized crossover design. Plasma levels of each substance, physiological parameters, and measures of psychopathology were taken at baseline and at regular intervals following ingestion of substances. Volunteers listened passively to words read and viewed a radial visual checkerboard in alternating blocks during fMRI scanning. Administration of THC was associated with increases in anxiety, intoxication, and positive psychotic symptoms, whereas CBD had no significant symptomatic effects. THC decreased activation relative to placebo in bilateral temporal cortices during auditory processing, and increased and decreased activation in different visual areas during visual processing. CBD was associated with activation in right temporal cortex during auditory processing, and when contrasted, THC and CBD had opposite effects in the right posterior superior temporal gyrus, the right-sided homolog to Wernicke's area. Moreover, the attenuation of activation in this area (maximum 61, −15, −2) by THC during auditory processing was correlated with its acute effect on psychotic symptoms. Single doses of THC and CBD differently modulate brain function in areas that process auditory and visual stimuli and relate to induced psychotic symptoms.
Journal Article
Dysfunctional insular connectivity during reward prediction in patients with first-episode psychosis
by
Lang, Undine E.
,
Schmidt, André
,
Palaniyappan, Lena
in
Adult
,
Anticipation, Psychological - physiology
,
Antipsychotic Agents - therapeutic use
2016
Increasing evidence indicates that psychosis is associated with abnormal reward processing. Imaging studies in patients with first-episode psychosis (FEP) have revealed reduced activity in diverse brain regions, including the ventral striatum, insula and anterior cingulate cortex (ACC), during reward prediction. However, whether these reductions in local brain activity are due to altered connectivity has rarely been explored.
We applied dynamic causal modelling and Bayesian model selection to fMRI data during the Salience Attribution Task to investigate whether patients with FEP showed abnormal modulation of connectivity between the ventral striatum, insula and ACC induced by rewarding cues and whether these changes were related to positive psychotic symptoms and atypical antipsychotic medication.
The model including reward-induced modulation of insula–ACC connectivity was the best fitting model in each group. Compared with healthy controls (n = 19), patients with FEP (n = 29) revealed reduced right insula–ACC connectivity. After subdividing patients according to current antipsychotic medication, we found that the reduced insula–ACC connectivity relative to healthy controls was observed only in untreated patients (n = 17), not in patients treated with antipsychotics (n = 12), and that it correlated negatively with unusual thought content in untreated patients with FEP.
The modest sample size of untreated patients with FEP was a limitation of our study.
This study indicates that insula–ACC connectivity during reward prediction is reduced in untreated patients with FEP and related to the formation of positive psychotic symptoms. Our study further suggests that atypical antipsychotics may reverse connectivity between the insula and the ACC during reward prediction.
Journal Article
Abnormal effective connectivity and psychopathological symptoms in the psychosis high-risk state
by
Radue, Ernst-Wilhelm
,
Schmidt, André
,
Walter, Marc
in
Adult
,
Bayes Theorem
,
Biological and medical sciences
2014
Recent evidence has revealed abnormal functional connectivity between the frontal and parietal brain regions during working memory processing in patients with schizophrenia and first-episode psychosis. However, it still remains unclear whether abnormal frontoparietal connectivity during working memory processing is already evident in the psychosis high-risk state and whether the connection strengths are related to psychopathological outcomes.
Healthy controls and antipsychotic-naive individuals with an at-risk mental state (ARMS) performed an n-back working memory task while undergoing functional magnetic resonance imaging. Effective connectivity between frontal and parietal brain regions during working memory processing were characterized using dynamic causal modelling.
Our study included 19 controls and 27 individuals with an ARMS. In individuals with an ARMS, we found significantly lower task performances and reduced activity in the right superior parietal lobule and middle frontal gyrus than in controls. Furthermore, the working memory–induced modulation of the connectivity from the right middle frontal gyrus to the right superior parietal lobule was significantly reduced in individuals with an ARMS, while the extent of this connectivity was negatively related to the Brief Psychiatric Rating Scale total score.
The modest sample size precludes a meaningful subgroup analysis for participants with a later transition to psychosis.
This study demonstrates that abnormal frontoparietal connectivity during working memory processing is already evident in individuals with an ARMS and is related to psychiatric symptoms. Thus, our results provide further insight into the pathophysiological mechanisms of the psychosis high-risk state by linking functional brain imaging, computational modelling and psychopathology.
Journal Article
A Single Dose of LSD Does Not Alter Gene Expression of the Serotonin 2A Receptor Gene (HTR2A) or Early Growth Response Genes (EGR1-3) in Healthy Subjects
by
Grünblatt, Edna
,
Liechti, Matthias E.
,
Dolder, Patrick C.
in
Brain research
,
Cortex (frontal)
,
Down-regulation
2017
Renewed interest has been seen in the use of lysergic acid diethylamide (LSD) in psychiatric research and practice. The repeated use of LSD leads to tolerance that is believed to result from serotonin (5-HT) 5-HT
receptor downregulation. In rats, daily LSD administration for 4 days decreased frontal cortex 5-HT
receptor binding. Additionally, a single dose of LSD acutely increased expression of the early growth response genes
and
in rat and mouse brains through 5-HT
receptor stimulation. No human data on the effects of LSD on gene expression has been reported. Therefore, we investigated the effects of single-dose LSD administration on the expression of the 5-HT
receptor gene (
) and
genes.
mRNA expression levels were analyzed in whole blood as a peripheral biomarker in 15 healthy subjects before and 1.5 and 24 h after the administration of LSD (100 μg) and placebo in a randomized, double-blind, placebo-controlled, cross-over study.
LSD did not alter the expression of the
or
genes 1.5 and 24 h after administration compared with placebo.
No changes were observed in the gene expression of LSD's primary target receptor gene or genes that are implicated in its downstream effects. Remaining unclear is whether chronic LSD administration alters gene expression in humans.
Journal Article
Pituitary gland volume in at-risk mental state for psychosis: a longitudinal MRI analysis
by
Tamagni, Corinne
,
Smieskova, Renata
,
Borgwardt, Stefan J.
in
Adrenocorticotropic Hormone - metabolism
,
Adult
,
Antipsychotics
2015
Pituitary enlargement has been reported in individuals with schizophrenic psychosis or an at-risk mental state for psychosis (ARMS). In a previous study, our group could show pituitary volume increase in first episode and ARMS patients with later transition to psychosis (ARMS-T). However, there are no longitudinal studies on this issue so far. We therefore examined longitudinally whether transition to psychosis would be accompanied by a further increase of pituitary volume in antipsychotic-naïve ARMS patients.
Magnetic resonance imaging (MRI) data were acquired from 23 antipsychotic-naïve individuals with an ARMS. Ten subjects developed psychosis (ARMS-T) and 13 did not (ARMS-NT). ARMS-T were re-scanned after the onset of psychosis, and ARMS-NT were re-scanned at the end of the study period.
There was no significant difference of the pituitary volume between ARMS-T and ARMS-NT in our sample, and there were no significant pituitary volume changes over time. Discussion Longitudinally, we could not detect any further volumetric changes in the pituitary volume with transition to psychosis.
This, together with the result of our previous study, could indicate that the perceived level of stress in ARMS patients is constantly high from very early onward.
Journal Article
Spatiotemporal distribution of white matter lesions in relapsing–remitting and secondary progressive multiple sclerosis
by
Radue, Ernst-Wilhelm
,
Polman, Chris
,
Mueller-Lenke, Nicole
in
Adult
,
Analysis of Variance
,
Biological and medical sciences
2012
Background:
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. MS lesions show a typical distribution pattern and primarily affect the white matter (WM) in the periventricular zone and in the centrum semiovale.
Objective:
To track lesion development during disease progression, we compared the spatiotemporal distribution patterns of lesions in relapsing–remitting MS (RRMS) and secondary progressive MS (SPMS).
Methods:
We used T1 and T2 weighted MR images of 209 RRMS and 62 SPMS patients acquired on two different 1.5 Tesla MR scanners in two clinical centers followed up for 25 (± 1.7) months. Both cross-sectional and longitudinal differences in lesion distribution between RRMS and SPMS patients were analyzed with lesion probability maps (LPMs) and permutation-based inference.
Results:
MS lesions clustered around the lateral ventricles and in the centrum semiovale. Cross-sectionally, compared to RRMS patients, the SPMS patients showed a significantly higher regional probability of T1 hypointense lesions (p≤0.03) in the callosal body, the corticospinal tract, and other tracts adjacent to the lateral ventricles, but not of T2 lesions (peak probabilities were RRMS: T1 9%, T2 18%; SPMS: T1 21%, T2 27%). No longitudinal changes of regional T1 and T2 lesion volumes between baseline and follow-up scan were found.
Conclusion:
The results suggest a particular vulnerability to neurodegeneration during disease progression in a number of WM tracts.
Journal Article
Anterior cingulate pathology in the prodromal stage of schizophrenia
by
Radue, Ernst-Wilhelm
,
McGuire, Philip
,
Riecher-Rössler, Anita
in
Brain
,
Gyrus Cinguli - pathology
,
Humans
2008
The authors observed that patients with schizophrenia have smaller bilateral anterior cingulate cortex (ACC) volume and decreased fractional anisotropy (FA) in the anterior cingulum compared with healthy controls. Regarding cingulate abnormalities, the ARMS group (independent of subsequent clinical outcome) showed areas of reduced grey matter volume in the bilateral posterior cingulate gyrus compared to healthy controls but no significant differences compared to patients with first-episode psychosis.
Journal Article
Multivariate pattern classification of gray matter pathology in multiple sclerosis
by
Klöppel, Stefan
,
Kuster, Pascal
,
Radue, Ernst-Wilhelm
in
Adult
,
Brain - pathology
,
Classification
2012
Univariate analyses have identified gray matter (GM) alterations in different groups of MS patients. While these methods detect differences on the basis of the single voxel or cluster, multivariate methods like support vector machines (SVM) identify the complex neuroanatomical patterns of GM differences. Using multivariate linear SVM analysis and leave-one-out cross-validation, we aimed at identifying neuroanatomical GM patterns relevant for individual classification of MS patients.
We used SVM to separate GM segmentations of T1-weighted three-dimensional magnetic resonance (MR) imaging scans within different age- and sex-matched groups of MS patients with either early (n=17) or late MS (n=17) (contrast I), low (n=20) or high (n=20) white matter lesion load (contrast II), and benign MS (BMS, n=13) or non-benign MS (NBMS, n=13) (contrast III) scanned on a single 1.5T MR scanner.
GM patterns most relevant for individual separation of MS patients comprised cortical areas of all the cerebral lobes as well as deep GM structures, including the thalamus and caudate. The patterns detected were sufficiently informative to separate individuals of the respective groups with high sensitivity and specificity in 85% (contrast I), 83% (contrast II) and 77% (contrast III) of cases.
The study demonstrates that neuroanatomical spatial patterns of GM segmentations contain information sufficient for correct classification of MS patients at the single case level, thus making multivariate SVM analysis a promising clinical application.
► First study using multivariate image analysis for classification of grey matter in MS. ► Up to 92% sensitivity and 90% classification accuracy in individual's unseen data. ► Advantage of multivariate analysis in allowing inferences at the individual’s level.
Journal Article
Structural brain abnormalities in individuals with an at-risk mental state who later develop psychosis
2007
Background: Neuroanatomical abnormalities are a well-established feature of schizophrenia. However, the timing of their emergence and the extent to which they are related to vulnerability to the disorder as opposed to psychotic illness itself is unclear. Aims: To assess regional grey matter volume in the at-risk individuals who subsequently developed psychosis. Method: Magnetic resonance imaging data from at-risk individuals who developed psychosis (n=12) within the following 25 months were compared with data from healthy volunteers (n=22) and people with first-episode psychosis (n=25). Results: Compared with healthy volunteers, individuals who subsequently developed psychosis had smaller grey matter volume in the posterior cingulate gyrus, precuneus, and paracentral lobule bilaterally and in the left superior parietal lobule, and greater grey matter volume in a left parietal/posterior temporal region. Compared with first-episode patients, they had relatively greater grey matter volume in the temporal gyrus bilaterally and smaller grey matter volume in the right lentiform nucleus. Conclusions: Some of the structural brain abnormalities in individuals with an at-risk mental state may be related to an increased vulnerability to psychosis, while others are associated with the development of a psychotic illness. Declaration of interest: None. See Acknowledgements for details of funding. Adapted from the source document.
Journal Article