Brain serotonin synthesis capacity in obsessive-compulsive disorder: effects of cognitive behavioral therapy and sertraline.

Cognitive behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are both effective treatments for some patients with obsessive-compulsive disorder (OCD), yet little is known about the neurochemical changes related to these treatment modalities. Here, we used positron emission tomography and the α-[11C]methyl-L-tryptophan tracer to examine the changes in brain regional serotonin synthesis capacity in OCD patients following treatment with CBT or SSRI treatment. Sixteen medication-free OCD patients were randomly assigned to 12 weeks of either CBT or sertraline treatment. Pre-to-post treatment changes in the α-[11C]methyl-L-tryptophan brain trapping constant, K* (ml/g/min), were assessed as a function of symptom response, and correlations with symptom improvement were examined. Responders/partial responders to treatment did not show significant changes in relative regional tracer uptake; rather, in responders/partial responders, 12 weeks of treatment led to serotonin synthesis capacity increases that were brain-wide. Irrespective of treatment modality, baseline serotonin synthesis capacity in the raphe nuclei correlated positively with clinical improvement. These observations suggest that, for some patients, successful remediation of OCD symptoms might be associated with greater serotonergic tone

Academic and psychological impact of cyber bullying

Bibliography: p. 67-76Includes copies of ethics approval. Original copies with original Partial Copyright Licence.Cyber bullying has emerged as a new form of bullying affecting a large portion of children. Children that were victims of cyber bullying (n = 239) in grades 6, 7, 10, and 11 were surveyed to. examine whether they experienced impaired academic performance and psychological well-being. Seven types of cyber bullying were identified. Through correlations the results demonstrated that all seven types of cyber bullying are significantly related to children's well-being. One-way ANOVAs and t-tests indicate that specific characteristics of the victim (sex, grade, and perpetrator) are associated with differential impact. In addition, this study found that deconstructing cyber bullying by type reveals unique information. For some types of cyber bullying, for example, girls and young children report more severe impact than boys and older children. Overall, the study demonstrates the importance of examining different types of cyber bullying to gain an understanding of children's experiences of this phenomenon

L’effet psychologique de cyber-intimidation : Implications pour les conseillers scolaires

Cyber-bullying is asignificant problem for children today. This study provides evidence of the psychological impact of cyber-bullying among victimized children ages 10 to 17 years (M = 12.48, SD = 1.79) from 23 urban schools in a western province of Canada (N = 239). Students who were cyber-bullied reported high levels of anxious, externalizing, and depressed feelings/behaviours for all types of cyber-bullying they experienced, with girls reporting more severe impact than boys. Strategies are discussed for school counsellors working with youth who have been victimized through electronic means.Cyber-intimidation est un problème important pour les enfants d’aujourd’ hui. Cette étude fournit des preuves de l’effet psychologique de la cyber-intimidation chez les victimes, des enfants âgés de 10 à 17 ans (M = 12,48, SD = 1,79) de 23 écoles urbaines dans une province de l’ouest du Canada (N = 239). Les étudiants, victimes de cyber-intimidation, ont déclaré avoir vécu des sentiments et des comportements d’anxiété, d’extériorisation, et de dépression pour tous les types de cyber-intimidation qu’ils ont vécus. Les filles ont indiqué des effets plus sévères que les garçons. Des stratégies sont discutées pour les conseillers scolaires qui travaillent avec des jeunes victimes de cyber-intimidation par moyen de média électronique

Brain serotonin synthesis capacity in obsessive-compulsive disorder: effects of cognitive behavioral therapy and sertraline.

Cognitive behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are both effective treatments for some patients with obsessive-compulsive disorder (OCD), yet little is known about the neurochemical changes related to these treatment modalities. Here, we used positron emission tomography and the α-[11C]methyl-L-tryptophan tracer to examine the changes in brain regional serotonin synthesis capacity in OCD patients following treatment with CBT or SSRI treatment. Sixteen medication-free OCD patients were randomly assigned to 12 weeks of either CBT or sertraline treatment. Pre-to-post treatment changes in the α-[11C]methyl-L-tryptophan brain trapping constant, K* (ml/g/min), were assessed as a function of symptom response, and correlations with symptom improvement were examined. Responders/partial responders to treatment did not show significant changes in relative regional tracer uptake; rather, in responders/partial responders, 12 weeks of treatment led to serotonin synthesis capacity increases that were brain-wide. Irrespective of treatment modality, baseline serotonin synthesis capacity in the raphe nuclei correlated positively with clinical improvement. These observations suggest that, for some patients, successful remediation of OCD symptoms might be associated with greater serotonergic tone

A Genome-wide Association Study of Autism Using the Simons Simplex Collection: Does Reducing Phenotypic Heterogeneity in Autism Increase Genetic Homogeneity?

BACKGROUND: Phenotypic heterogeneity in autism has long been conjectured to be a major hindrance to the discovery of genetic risk factors, leading to numerous attempts to stratify children based on phenotype to increase power of discovery studies. This approach, however, is based on the hypothesis that phenotypic heterogeneity closely maps to genetic variation, which has not been tested. Our study examines the impact of sub-phenotyping of a well-characterized ASD sample on genetic homogeneity and the ability to discover common genetic variants conferring liability to ASD. METHODS: Genome-wide genotypic data of 2576 families from the Simons Simplex Collection (SSC) were analyzed in the overall sample and phenotypic subgroups defined on the basis of diagnosis, IQ, and symptom profiles. We conducted a family-based association study as well as estimating heritability and evaluating allele scores for each phenotypic subgroup. RESULTS: Association analyses revealed no genome-wide significant association signal. Sub-phenotyping did not increase power substantially. Moreover, allele scores built from the most associated SNPs, based on the odds ratio in the full sample, predicted case status in subsets of the sample equally well and heritability estimates were very similar for all subgroups. CONCLUSIONS: In genome-wide association analysis of the SSC sample, reducing phenotypic heterogeneity had at most a modest impact on genetic homogeneity. Our results are based on a relatively small sample, one with greater homogeneity than the entire population; if they apply more broadly, they imply that analysis of sub-phenotypes is not a productive path forward for discovering genetic risk variants in ASD