118 resultados para Autistic Disorder


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In the rodent forebrain GABAergic neurons are generated from progenitor cells that express the transcription factors Dlx1 and Dlx2. The Rap-1 guanine nucleotide exchange factor, MR-GEF, is turned on by many of these developing GABAergic neurons. Expression of both Dlx1/2 and MR-GEF is retained in both adult mouse and human forebrain where, in human, decreased Dlx1 expression has been associated with psychosis. Using in situ hybridization studies we show that MR-GEF expression is significantly down-regulated in the forebrain of Dlx1/2 double mutant mice suggesting that MR-GEF and Dlx1/2 form part of a common signalling pathway during GABAergic neuronal development. We therefore compared MR-GEF expression by in situ hybridization in individuals with major psychiatric disorders (schizophrenia, bipolar disorder, major depression) and control individuals. We observed a significant positive correlation between layers II and IV of the dorso-lateral prefrontal cortex (DLPFC) in the percentage of MR-GEF expressing neurons in individuals with bipolar disorder, but not in individuals with schizophrenia, major depressive disorder or in controls. Since MR-GEF encodes a Rap1 GEF able to activate G-protein signalling, we suggest that changes in MR-GEF expression could potentially influence neurotransmission.

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Background Two specific cognitive constructs that have been implicated in the development and maintenance of anxiety symptoms are anxiety sensitivity and emotional reasoning, both of which relate to the experience and meaning of physical symptoms of arousal or anxiety. The interpretation of physical symptoms has been particularly implicated in theories of social anxiety disorder, where internal physical symptoms are hypothesized to influence the individual's appraisals of the self as a social object. Method The current study compared 75 children on measures of anxiety sensitivity and emotional reasoning: 25 with social anxiety disorder, 25 with other anxiety disorders, and 25 nonanxious children (aged 7–12 years). Results Children with social anxiety disorder reported higher levels of anxiety sensitivity and were more likely than both other groups to view ambiguous situations as anxiety provoking, whether physical information was present or not. There were no group differences in the extent to which physical information altered children's interpretation of hypothetical scenarios. Limitations This study is the first to investigate emotional reasoning in clinically anxious children and therefore replication is needed. In addition, those in both anxious groups commonly had comorbid conditions and, consequently, specific conclusions about social anxiety disorder need to be treated with caution. Conclusion The findings highlight cognitive characteristics that may be particularly pertinent in the context of social anxiety disorder in childhood and which may be potential targets for treatment. Furthermore, the findings suggest that strategies to modify these particular cognitive constructs may not be necessary in treatments of some other childhood anxiety disorders.

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Deficits in facial mimicry have been widely reported in autism. Some studies have suggested that these deficits are restricted to spontaneous mimicry and do not extend to volitional mimicry. We bridge these apparently inconsistent observations, by testing the impact of reward value on neural indices of mimicry, and how autistic traits modulate this impact. Neutral faces were conditioned with high and low reward. Subsequently, functional connectivity between the ventral striatum (VS) and inferior frontal gyrus (IFG) was measured whilst neurotypical adults (n = 30) watched happy expressions made by these conditioned faces. We found greater VS-IFG connectivity in response to high-reward vs. low-reward happy faces. This difference was negatively proportional to autistic traits, suggesting that reduced spontaneous mimicry of social stimuli seen in autism, maybe related to a failure in the modulation of the mirror system by the reward system rather than a circumscribed deficit in the mirror system.

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Modelling of disorder in organic crystals is highly desirable since it would allow thermodynamic stabilities and other disorder-sensitive properties to be estimated for such systems. Two disordered organic molecular systems are modeled using a symmetry-adapted ensemble approach, in which the disordered system is treated as an ensemble of the configurations of a supercell with respect to substitution of one disorder component for another. Computation time is kept manageable by performing calculations only on the symmetrically inequivalent configurations. Calculations are presented on a substitutionally disordered system, the dichloro/dibromobenzene solid solution, and on an orientationally disordered system, eniluracil, and the resultant free energies, disorder patterns, and system properties are discussed. The results are found to be in agreement with experiment following manual removal of physically implausible configurations from ensemble averages, highlighting the dangers of a completely automated approach to organic crystal thermodynamics which ignores the barriers to equilibration once the crystal has been formed.

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The current study explored whether individuals diagnosed with schizophrenia and a high level of PTSD symptoms experience more frequent neutral intrusive memories than individuals diagnosed with schizophrenia with low level PTSD symptoms. Results supported a vulnerability to neutral intrusive memories within the comorbid group, which did not seem to be related to psychotic symptom severity. It is possible that a subgroup of psychotic individuals’ process information in a manner that make them susceptible to frequent intrusive memories, characteristic of a PTSD presentation. A longitudinal study is required to specify the development of this vulnerability so as to inform future interventions.

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Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are often comorbid and share cognitive abnormalities in temporal foresight. A key question is whether shared cognitive phenotypes are based on common or different underlying pathophysiologies and whether comorbid patients have additive neurofunctional deficits, resemble one of the disorders or have a different pathophysiology. We compared age- and IQ-matched boys with non-comorbid ADHD (18), non-comorbid ASD (15), comorbid ADHD and ASD (13) and healthy controls (18) using functional magnetic resonance imaging (fMRI) during a temporal discounting task. Only the ASD and the comorbid groups discounted delayed rewards more steeply. The fMRI data showed both shared and disorder-specific abnormalities in the three groups relative to controls in their brain-behaviour associations. The comorbid group showed both unique and more severe brain-discounting associations than controls and the non-comorbid patient groups in temporal discounting areas of ventromedial and lateral prefrontal cortex, ventral striatum and anterior cingulate, suggesting that comorbidity is neither an endophenocopy of the two pure disorders nor an additive pathology.

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Objective Sustained attention problems are common in people with autism spectrum disorder (ASD) and may have significant implications for the diagnosis and management of ASD and associated comorbidities. Furthermore, ASD has been associated with atypical structural brain development. The authors used functional MRI to investigate the functional brain maturation of attention between childhood and adulthood in people with ASD. Method Using a parametrically modulated sustained attention/vigilance task, the authors examined brain activation and its linear correlation with age between childhood and adulthood in 46 healthy male adolescents and adults (ages 11–35 years) with ASD and 44 age- and IQ-matched typically developing comparison subjects. Results Relative to the comparison group, the ASD group had significantly poorer task performance and significantly lower activation in inferior prefrontal cortical, medial prefrontal cortical, striato-thalamic, and lateral cerebellar regions. A conjunction analysis of this analysis with group differences in brain-age correlations showed that the comparison group, but not the ASD group, had significantly progressively increased activation with age in these regions between childhood and adulthood, suggesting abnormal functional brain maturation in ASD. Several regions that showed both abnormal activation and functional maturation were associated with poorer task performance and clinical measures of ASD and inattention. Conclusions The results provide first evidence that abnormalities in sustained attention networks in individuals with ASD are associated with underlying abnormalities in the functional brain maturation of these networks between late childhood and adulthood.

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Autism Spectrum Disorder (ASD) is diagnosed on the basis of behavioral symptoms, but cognitive abilities may also be useful in characterizing individuals with ASD. One hundred seventy-eight high-functioning male adults, half with ASD and half without, completed tasks assessing IQ, a broad range of cognitive skills, and autistic and comorbid symptomatology. The aims of the study were, first, to determine whether significant differences existed between cases and controls on cognitive tasks, and whether cognitive profiles, derived using a multivariate classification method with data from multiple cognitive tasks, could distinguish between the two groups. Second, to establish whether cognitive skill level was correlated with degree of autistic symptom severity, and third, whether cognitive skill level was correlated with degree of comorbid psychopathology. Fourth, cognitive characteristics of individuals with Asperger Syndrome (AS) and high-functioning autism (HFA) were compared. After controlling for IQ, ASD and control groups scored significantly differently on tasks of social cognition, motor performance, and executive function (P's < 0.05). To investigate cognitive profiles, 12 variables were entered into a support vector machine (SVM), which achieved good classification accuracy (81%) at a level significantly better than chance (P < 0.0001). After correcting for multiple correlations, there were no significant associations between cognitive performance and severity of either autistic or comorbid symptomatology. There were no significant differences between AS and HFA groups on the cognitive tasks. Cognitive classification models could be a useful aid to the diagnostic process when used in conjunction with other data sources-including clinical history.

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Families living with autism often feel unable to attend social and cultural events largely due to the fear of their child attracting negative or even aggressive reactions from others. The ‘joint attention’ that is part of the theatre experience however may be a powerful factor in the development of social and communication skills for such children. ‘Relaxed performances’ offer an opportunity for them to access and engage with theatre by making special arrangements designed to reduce tensions associated with visits to public places. Aspects of the production such as the use of lighting and sound effects which may trigger adverse reactions are also adjusted. This paper reports on how one local theatre drew on the findings of a national project to mount a ‘relaxed performance’ of their annual pantomime. It discusses the theatre’s preparations and presents evidence of the impact the event had on local children with autism and their families. The success of both the national and this local project marks a new beginning for improved access to the theatre for an audience that has hitherto felt largely excluded.

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Background Social communication deficits are prevalent amongst children with anxiety disorders; however whether they are over-represented specifically among children with Social Anxiety Disorder has not been examined. This study set out to examine social communication deficits among children with Social Anxiety Disorder in comparison to children with other forms of anxiety disorder. Methods Parents of 404 children with a diagnosed anxiety disorder completed the Social Communication Questionnaire (SCQ; Rutter, M., Bailey, A., Lord, C., 2003. The Social Communication Questionnaire – Manual. Western Psychological Services, Los Angeles, CA). Children with a diagnosis of Social Anxiety Disorder (n=262) and anxious children without Social Anxiety Disorder (n=142) were compared on SCQ total and subscale scores and the frequency of participants scoring above clinical cut-offs. Results Children with Social Anxiety Disorder scored significantly higher than anxious children without Social Anxiety Disorder on the SCQ total (t(352)=4.85, p<.001, d=.55, r=.27), Reciprocal Social Interaction (t(351)=4.73, p<.001, d=.55, r=.27), communication (t(344)=3.62, p<.001, d=.43, r=.21) and repetitive, restrictive and stereotyped behaviors subscales (t(353)=3.15, p=.002, d=.37, r=.18). Furthermore, children with Social Anxiety Disorder were three times more likely to score above clinical cut-offs. Limitations The participants were a relatively affluent group of predominantly non-minority status. The social communication difficulties measure relied on parental report which could be influenced by extraneous factors. Conclusions Treatments for Social Anxiety Disorder may benefit from a specific focus on developing social communication skills. Future research using objective assessments of underlying social communication skills is required.

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Children with an autism spectrum disorder (ASD) may be vulnerable to social isolation and bullying. We measured the friendship, fighting/bullying and victimization experiences of 10–12-year-old children with an ASD (N = 100) using parent, teacher and child self-report. Parent and teacher reports were compared to an IQ-matched group of children with special educational needs (SEN) without ASD (N = 80) and UK population data. Parents and teachers reported a lower prevalence of friendships compared to population norms and to children with SEN without an ASD. Parents but not teachers reported higher levels of victimization than the SEN group. Half of the children with an ASD reported having friendships that involved mutuality. By teacher report children with an ASD who were less socially impaired in mainstream school experienced higher levels of victimization than more socially impaired children; whereas for more socially impaired children victimization did not vary by school placement. Strategies are required to support and improve the social interaction skills of children with an ASD, to enable them to develop and maintain meaningful peer friendships and avoid victimization.

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Background Psychophysiological theories suggest that individuals with anxiety disorders may evidence inflexibility in their autonomic activity at rest and when responding to stressors. In addition, theories of social anxiety disorder, in particular, highlight the importance of physical symptoms. Research on autonomic activity in childhood (social) anxiety disorders, however, is scarce and has produced inconsistent findings, possibly because of methodological limitations. Method The present study aimed to account for limitations of previous studies and measured respiratory sinus arrhythmia (RSA) and heart rate (HR) using Actiheart heart rate monitors and software (Version 4) during rest and in response to a social and a non-social stressor in 60 anxious (30 socially anxious and 30 ‘other’ anxious), and 30 nonanxious sex-and age-matched 7–12 year olds. In addition, the effect of state anxiety during the tasks was explored. Results No group differences at rest or in response to stress were found. Importantly, however, with increases in state anxiety, all children, regardless of their anxiety diagnoses showed less autonomic responding (i.e., less change in HR and RSA from baseline in response to task) and took longer to recover once the stressor had passed. Limitations This study focused primarily on parasympathetic arousal and lacked measures of sympathetic arousal. Conclusion The findings suggest that childhood anxiety disorders may not be characterized by inflexible autonomic responding, and that previous findings to the contrary may have been the result of differences in subjective anxiety between anxious and nonanxious groups during the tasks, rather than a function of chronic autonomic dysregulation.

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Parental behaviors, most notably overcontrol, lack of warmth and expressed anxiety, have been implicated in models of the development and maintenance of anxiety disorders in children and young people. Theories of normative development have proposed that different parental responses are required to support emotional development in childhood and adolescence, yet age has not typically been taken into account in studies of parenting and anxiety disorders. In order to identify whether associations between anxiety disorder status and parenting differ in children and adolescents, we compared observed behaviors of parents of children (7–10 years) and adolescents (13–16 years) with and without anxiety disorders (n=120), while they undertook a series of mildly anxiety-provoking tasks. Parents of adolescents showed significantly lower levels of expressed anxiety, intrusiveness and warm engagement than parents of children. Furthermore, offspring age moderated the association between anxiety disorder status and parenting behaviors. Specifically, parents of adolescents with anxiety disorders showed higher intrusiveness and lower warm engagement than parents of non-anxious adolescents. A similar relationship between these parenting behaviors and anxiety disorder status was not observed among parents of children. The findings suggest that theoretical accounts of the role of parental behaviors in anxiety disorders in children and adolescents should distinguish between these different developmental periods. Further experimental research to establish causality, however, would be required before committing additional resources to targeting parenting factors within treatment.

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Background Models of the development and maintenance of childhood anxiety suggest an important role for parent cognitions: that is, negative expectations of children's coping abilities lead to parenting behaviors that maintain child anxiety. The primary aims of the current study were to (1) compare expectations of child vulnerability and coping among mothers of children with anxiety disorders on the basis of whether or not mothers also had a current anxiety disorder, and (2) examine the degree to which the association between maternal anxiety disorder status and child coping expectations was mediated by how mothers interpreted ambiguous material that referred to their own experience. Methods The association between interpretations of threat, negative emotion, and control was assessed using hypothetical ambiguous scenarios in a sample of 271 anxious and nonanxious mothers of 7- to 12-year-old children with an anxiety disorder. Mothers also rated their expectations when presented with real life challenge tasks. Results There was a significant association between maternal anxiety disorder status and negative expectations of child coping behaviors. Mothers’ self-referent interpretations were found to mediate this relationship. Responses to ambiguous hypothetical scenarios correlated significantly with responses to real life challenge tasks. Conclusions Treatments for childhood anxiety disorders in the context of parental anxiety disorders may benefit from the inclusion of a component to directly address parental cognitions. Some inconsistencies were found when comparing maternal expectations in response to hypothetical scenarios with real life challenges. This should be addressed in future research.

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Background Atypical self-processing is an emerging theme in autism research, suggested by lower self-reference effect in memory, and atypical neural responses to visual self-representations. Most research on physical self-processing in autism uses visual stimuli. However, the self is a multimodal construct, and therefore, it is essential to test self-recognition in other sensory modalities as well. Self-recognition in the auditory modality remains relatively unexplored and has not been tested in relation to autism and related traits. This study investigates self-recognition in auditory and visual domain in the general population and tests if it is associated with autistic traits. Methods Thirty-nine neurotypical adults participated in a two-part study. In the first session, individual participant’s voice was recorded and face was photographed and morphed respectively with voices and faces from unfamiliar identities. In the second session, participants performed a ‘self-identification’ task, classifying each morph as ‘self’ voice (or face) or an ‘other’ voice (or face). All participants also completed the Autism Spectrum Quotient (AQ). For each sensory modality, slope of the self-recognition curve was used as individual self-recognition metric. These two self-recognition metrics were tested for association between each other, and with autistic traits. Results Fifty percent ‘self’ response was reached for a higher percentage of self in the auditory domain compared to the visual domain (t = 3.142; P < 0.01). No significant correlation was noted between self-recognition bias across sensory modalities (τ = −0.165, P = 0.204). Higher recognition bias for self-voice was observed in individuals higher in autistic traits (τ AQ = 0.301, P = 0.008). No such correlation was observed between recognition bias for self-face and autistic traits (τ AQ = −0.020, P = 0.438). Conclusions Our data shows that recognition bias for physical self-representation is not related across sensory modalities. Further, individuals with higher autistic traits were better able to discriminate self from other voices, but this relation was not observed with self-face. A narrow self-other overlap in the auditory domain seen in individuals with high autistic traits could arise due to enhanced perceptual processing of auditory stimuli often observed in individuals with autism.