179 research outputs found
Using simple economic games to assess social orienting and prosocial behavior in adolescents with autism spectrum disorder
Deficits in socio-emotional reciprocity, in prosocial behavior and in developing social relationships are diagnostic criteria of autism spectrum disorder (ASD), usually assessed by self-report or observation. Simple social experiments developed by behavioral economists allow for quantification of ASD-related social behavior. In this study, we used such experiments to compare social-economic decision-making between ASD adolescents and neurotypical controls. Precisely, we analyzed social orienting and prosocial behavior in 17 adolescents with ASD (Asperger syndrome) and 24 matched neurotypical adolescents. We used a two-condition distribution game (possibility of punishment by fellow player versus no such possibility) and an impunity game to examine social orienting (distribution game) and prosocial behavior (both games). Participants with ASD exhibited less social orienting in the distribution game (p = 0.03, d = -0.61). In addition, there was a trend for ASD participants to behave in a more prosocial way than neurotypical participants in the impunity game (p = 0.08, d = 0.60), which was not the case in the no-punishment condition of the distribution game (p = 0.35, r = 0.17). These results demonstrate the potential of simple economic games to capture reduced social orienting in ASD. The unexpected finding of more prosocial behavior in adolescents with autism spectrum disorder than in neurotypical controls adds to the complexity of previously published results. We recommend meta-analytic efforts to determine average effect sizes across studies and elucidate the conditions for prosocial behavior in ASD to occur
The effects of catecholamine depletion on the neural response to fearful faces in remitted depression
Recent evidence suggests that increased psychophysiological response to negatively valenced emotional stimuli found in major depressive disorder (MDD) may be associated with reduced catecholaminergic neurotransmission. Fourteen unmedicated, remitted subjects with MDD (RMDD) and 13 healthy control subjects underwent catecholamine depletion with oral α-methyl-para-tyrosine (AMPT) in a randomized, placebo-controlled, double-blind crossover trial. Subjects were exposed to fearful (FF) and neutral faces (NF) during a scan with [15O]H2O positron emission tomography to assess the brain-catecholamine interaction in brain regions previously associated with emotional face processing. Treatment with AMPT resulted in significantly increased, normalized cerebral blood flow (CBF) in the left inferior temporal gyrus (ITG) and significantly decreased CBF in the right cerebellum across conditions and groups. In RMDD, flow in the left posterior cingulate cortex (PCC) increased significantly in the FF compared to the NF condition after AMPT, but remained unchanged after placebo, whereas healthy controls showed a significant increase under placebo and a significant decrease under AMPT in this brain region. In the left dorsolateral prefrontal cortex (DLPFC), flow decreased significantly in the FF compared to the NF condition under AMPT, and increased significantly under placebo in RMDD, whereas healthy controls showed no significant differences. Differences between AMPT and placebo of within-session changes in worry-symptoms were positively correlated with the corresponding changes in CBF in the right subgenual prefrontal cortex in RMDD. In conclusion, this study provided evidence for a catecholamine-related modulation of the neural responses to FF expressions in the left PCC and the left DLPFC in subjects with RMDD that might constitute a persistent, trait-like abnormality in MDD
Neural correlates of free T3 alteration after catecholamine depletion in subjects with remitted major depressive disorder and in controls
RATIONALE: Thyroid hormones and their interactions with catecholamines play a potentially important role in alterations of mood and cognition.
OBJECTIVES: This study aimed to examine the neurobiological effects of catecholamine depletion on thyroid hormones by measuring endocrine and cerebral metabolic function in unmedicated subjects with remitted major depressive disorder (RMDD) and in healthy controls.
METHODS: This was a randomized, placebo-controlled, and double-blind crossover trial that included 15 unmedicated RMDD subjects and 13 healthy control subjects. The participants underwent two 3-day-long sessions at 1-week intervals; each participant was randomly administered oral α-methyl-para-tyrosine in one session (catecholamine depletion) and an identical capsule containing hydrous lactose (sham depletion) in the other session prior to a [(18)F]-fluorodeoxyglucose positron emission tomography scan.
RESULTS: Serum concentrations of free T3 (FT3), free T4 (FT4), and TSH were obtained and assessed with respect to their relationship to regional cerebral glucose metabolism. Both serum FT3 (P = 0.002) and FT4 (P = 0.0009) levels were less suppressed after catecholamine depletion compared with placebo treatment in the entire study sample. There was a positive association between both FT3 (P = 0.0005) and FT4 (P = 0.002) and depressive symptoms measured using the Montgomery-Åsberg Depression Rating Scale. The relative elevation in FT3 level was correlated with a decrease in regional glucose metabolism in the right dorsolateral prefrontal cortex (rDLPFC; P < 0.05, corrected).
CONCLUSIONS: This study provided evidence of an association between a thyroid-catecholamine interaction and mood regulation in the rDLPFC
Analysis of recreational psychedelic substance use experiences classified by substance
RATIONALE AND OBJECTIVES
Differences among psychedelic substances regarding their subjective experiences are clinically and scientifically interesting. Quantitative linguistic analysis is a powerful tool to examine such differences. This study compared five psychedelic substance report groups and a non-psychedelic report group on quantitative linguistic markers of psychological states and processes derived from recreational use-based online experience reports.
METHODS
Using 2947 publicly available online reports, we compared Ayahuasca and N,N-dimethyltryptamine (DMT, analyzed together), ketamine, lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), psilocybin (mushroom), and antidepressant drug use experiences. We examined word frequencies related to various psychological states and processes and semantic proximity to psychedelic and mystical experience scales.
RESULTS
Linguistic markers of psychological function indicated distinct effect profiles. For example, MDMA experience reports featured an emotionally intensifying profile accompanied by many cognitive process words and dynamic-personal language. In contrast, Ayahuasca and DMT experience reports involved relatively little emotional language, few cognitive process words, increased analytical thinking-associated language, and the most semantic similarity with psychedelic and mystical experience descriptions. LSD, psilocybin mushroom, and ketamine reports showed only small differences on the emotion-, analytical thinking-, psychedelic, and mystical experience-related language outcomes. Antidepressant reports featured more negative emotional and cognitive process-related words, fewer positive emotional and analytical thinking-related words, and were generally not similar to mystical and psychedelic language.
CONCLUSION
This article addresses an existing research gap regarding the comparison of different psychedelic drugs on linguistic profiles of psychological states, processes, and experiences. The large sample of experience reports involving multiple psychedelic drugs provides valuable information that would otherwise be difficult to obtain. The results could inform experimental research into psychedelic drug effects in healthy populations and clinical trials for psychedelic treatments of psychiatric problems
Sustained Improvement of Negative Self-Schema After a Single Ketamine Infusion: An Open-Label Study
Conventional antidepressants have several important limitations, including a lack of direct effects on negative self-schema, which is at the core of Beck’s cognitive theory of depression. Based on previous studies showing a positive effect of ketamine on negative cognition, we compared reductions in negative self-schema between responders and non-responders to a single infusion of ketamine. In an open-label study, 26 participants with treatment-resistant depression received 0.5 mg/kg ketamine via infusion. Depression symptoms were assessed at baseline, 24 h, and 7 days after treatment with Montgomery-Åsberg Depression Rating Scale (MADRS) and Beck Depression Inventory (BDI-II). Nine of the 26 participants fulfilled response criteria after 24 h. Of these, eight still fulfilled response criteria after 7 days. Response was defined as a reduction in MADRS total score of 50% or more. Responders improved significantly more than non-responders both 24 h and 7 days after ketamine treatment on the following BDI-II items: item 1 (“Sadness”), item 7 (“Self-Dislike”), and item 8 (“Self- Criticalness”). These results suggest an important therapeutic effect of ketamine on negative self-schema, which is a fundamental cognitive aspect of depression. This effect is unique and might be associated with ketamine’s profound effects on neuroplasticity. Small sample size and lack of a placebo control group are the major limitations of this study
Wozu braucht die Schweizer Psychiatrie angewandte Forschung?
Die Schweiz hat eine lange und erfolgreiche Tradition in der angewandten Forschung in der Psychiatrie und Psychotherapie. Wo steht sie derzeit und wohin geht die weitere EntÂwicklung aus der Sicht der Universitäten? Nach einer anfänglich grossen Begeisterung fĂĽr neurowissenschaftliche Forschung wird Âaktuell die anwendungsorientierte VersorÂgungs- und Therapieforschung wiederbelebt und mit den Neurowissenschaften besser verknĂĽpft
Human Endogenous Retroviruses as Pathogenic Factors in the Development of Schizophrenia.
Schizophrenia is a complex disorder, characterized by the interplay between genetic and environmental factors. Human endogenous retroviruses (HERVs), genetic elements that originated from infections by exogenous retroviruses millions of years ago, comprise ~8% of the human genome. Here, we provide a comprehensive review of accumulating evidence, detailing HERV aberrancies associated with schizophrenia. Studies examining the genome, transcriptome, and proteome of individuals with schizophrenia provide data that support the association of these viral elements with the disorder. Molecular differences can be found within the central nervous system and peripheral tissues. However, additional studies are needed to substantiate the reported link and to address several discrepancies among previous investigations. We further discuss potentially relevant pathogenic mechanisms to the development of schizophrenia
Increased Anxiety After Stimulation of the Right Inferior Parietal Lobe and the Left Orbitofrontal Cortex
Sustained anxiety is a key symptom of anxiety disorders and may be associated with neural activation in the right inferior parietal lobe (rIPL), particularly under unpredictable threat. This finding suggests a moderating role of the rIPL in sustained anxiety, which we tested in the current study. We applied cathodal or sham transcranial direct current stimulation (tDCS) to the rIPL as a symptom provocation method in 22 healthy participants in a randomized, double-blind, crossover study, prior to two recordings of cerebral blood flow (CBF). In between, we applied a threat-of-shock paradigm with three conditions: unpredictable (U), predictable (P), or no electric shocks (N). We hypothesized increased anxiety under U, but not under P or N. Furthermore, we expected reduced CBF in the rIPL after tDCS compared to sham. As predicted, anxiety was higher in the U than the P and N conditions, and active tDCS augmented this effect. While tDCS did not alter CBF in the rIPL, it did attenuate the observed increase in brain regions that typically increase activation as a response to anxiety. These findings suggest that the rIPL moderates sustained anxiety as a gateway to brain regions crucial in anxiety. Alternatively, anodal tDCS over the left orbitofrontal cortex (lOFC) may have increased anxiety through disruption of OFC-amygdala interactions
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