Acute tryptophan depletion Moja-De: a method to study central nervous serotonin function in children and adolescents

Serotonin (5-HT) is widely implicated as a key neurotransmitter relevant to a range of psychiatric disorders and psychological processes. The role of central nervous 5-HT function underlying these processes can be examined through serotonergic challenge methodologies. Acute tryptophan depletion (ATD) is a key challenge method whereby a diminished dietary intake of tryptophan—the amino acid precursor to brain 5-HT synthesis—results in temporary diminished central nervous 5-HT synthesis. While this particular methodology has been used in adult populations, it was only recently that modifications were made to enable the use of ATD in child and adolescent populations. Additionally, the Moja-De modification of the ATD challenge methodology has demonstrated benefits over other ATD techniques used previously. The aim of this protocol paper is to describe the ATD Moja-De methodology in detail, its benefits, as well as studies that have been conducted to validate the procedure in child and adolescent samples. The ATD Moja-De protocol provides a potential methodology for investigating the role of central nervous 5-HT via manipulation of brain tryptophan availability in human psychopathology from a developmental viewpoint

Moral Disengagement of Pure Bullies and Bully/Victims: Shared and Distinct Mechanisms

The vast majority of adolescents recognize that bullying is morally wrong, yet bullying remains a problem in secondary schools, indicating young people may disengage from their moral values to engage in bullying. But it is unclear whether the same mechanisms enabling moral disengagement are active for bully/victims (who both bully and are bullied) as for pure bullies (who are not targets of bullying). This study tested the hypotheses that mechanisms of moral disengagement, including blaming the victim and minimizing the impact of bullying, may operate differently in bully/victims compared to pure bullies. From a sample of 1895 students from grades 7–9 (50.6% female; 83.4% from English speaking homes), 1870 provided self-reports on bullying involvement and mechanisms of moral disengagement associated with bullying. Two cut-offs were compared for bullying involvement (as perpetrator and as target of bullying) during the previous school term: a conservative cut-off (every few weeks or more often) and a liberal cut-off (once-or-twice). Using the conservative cut-off, both pure bullies and bully/victims enlisted moral disengagement mechanisms to justify bullying more than did uninvolved students and pure victims, with no significant difference in scores on any of the moral disengagement scales between pure bullies and bully/victims. For the liberal cut-off, bully/victims reported lower overall moral disengagement scores than did pure bullies, and specifically less distortion of consequences, diffusion of responsibility, and euphemistic labeling. This study advances bullying research by extending the role of moral disengagement in bullying episodes beyond pure bullies to victims, both pure victims and bully/victims. Examination of specific moral disengagement mechanisms and the extent of involvement in bullying enabled a more nuanced differentiation between the bullying groups. These results will inform future interventions aimed at reducing the use of moral disengagement mechanisms that sustain bullying and victimization. Targeted interventions are needed to challenge specific moral disengagement mechanisms from the perspectives of pure bullies and bully/victims.</p

STUDI PERILAKU SEKSUAL PADA KELOMPOK GAY :PENGETAHUAN, SIKAP DAN NILAI DI GUBUG SEBAYA KABUPATEN JOMBANG

<p><b>Objectives:</b> Recent research suggested an influence of diminished central nervous serotonin (5-HT) synthesis on the leptin axis via immunological mechanisms in healthy adult females. However, studies assessing immunological parameters in combination with dietary challenge techniques that impact brain 5-HT synthesis in humans are lacking. </p> <p><b>Methods:</b> In the present trial, a pilot analysis was conducted on data obtained in healthy adult humans receiving either different dietary acute tryptophan depletion (ATD) challenge or tryptophan (TRP)-balanced control conditions (BAL) to study the effects of reduced central nervous 5-HT synthesis on serum tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 concentrations. The data of <i>N</i> = 35 healthy adults were analysed who were randomly subjected to one of the following two dietary conditions in a double-blind between-subject approach: (1) The Moja-De ATD challenge (ATD), or (2) TRP-balanced control condition for ATD Moja-De (BAL). Serum concentrations for the assessment of relevant parameters (TNF-α, IL-1β and IL-6) and relevant TRP-related characteristics after the respective challenge procedures were assessed at baseline (T0) and in hourly intervals after administration over a period of 6 h (T1–T6). </p> <p><b>Results:</b> The ATD condition did not result in significant changes to cytokine concentrations for the entire study sample, or in male and female subgroups. Depletion of CNS 5-HT via dietary TRP depletion appears to have no statistically significant short-term impact on cytokine concentrations in healthy adults. </p> <p><b>Conclusions:</b> Future research on immunological stressors in combination with challenge techniques will be of value in order to further disentangle the complex interplay between brain 5-HT synthesis and immunological pathways.</p

Negative affect, attentional flexibility, and the development of sensorimotor intelligence

grantor: University of TorontoThis study tests attentional flexibility (AF), a predictor of competence, as a mediator of individual differences in distress regulation and in the timing of sensorimotor means-end skills. This proposition was assessed through analysis of data from a study of 12 infants over 16 visits during their first year. Regulation and AF were assessed from videotaping infant responses to a frustrating procedure. Sensorimotor skills were also assessed. Associations were found between distress regulation at 2-4 months, AF at 4-8 months, and means-end coordination at 8-10 months. Poor regulation predicted the co-occurrence of scanning and an agitated emotional state. Such co-occurence predicted the timing of acquisition of means-end skills. These results suggest that the timing of skill acquisition was predicated on the infant's developmental history. The implications of these findings for a model of cascading constraints on pathways to competence are discussed.M.A

Does the risk outweigh the benefits? Adolescent responses to completing health surveys

The aim of this study is to describe the self‐reported experiences of adolescents in population‐based samples when completing health‐related surveys on topics with varying potential for evoking distress. Survey data were collected in three school‐based studies of bullying behaviors (N = 1,771, 12–14 years), alcohol use (N = 823, 12, 15, and 17 years), and electronic image sharing (N = 274, 13 years). Between 5% and 15% of respondents reported being upset at survey completion, but at most 1.4% were entirely negative in their evaluation. Age was not associated with being upset, but younger adolescents were more likely to see benefit in participation. Although concurrent mental health symptoms increased the risk of being upset, this was mostly mitigated by perceived benefits from participation