Post-traumatic stress symptoms of children and adolescents exposed to the 2008 Wenchuan Earthquake: A longitudinal study of 5-HTTLPR genotype main effects and gene–environment interactions

Experiencing disasters causes severe mental disorders, among which post-traumatic stress disorder (PTSD) is the most common. We conducted a longitudinal study to examine the effect of 5-hydroxyl tryptamine transporter gene-linked polymorphic region (5-HTTLPR) genotype on child and adolescent PTSD symptom course after the 2008 Wenchuan Earthquake. We genotyped 963 participants who personally experienced the earthquake. PTSD symptoms were measured by University of California, Los Angeles PTSD reaction index at 2.5, 3.5, 4.5 and 5.5 years after the earthquake, respectively. Latent growth model was utilised to examine the main effect and gene–environment interaction effect of 5-HTTLPR on PTSD's symptom course. 5-HTTLPR genotype predicted initial PTSD symptom severity (β = 0.108, p = .019) and rates of symptom recovery (β = −0.120, p = .031) between 2.5 and 5.5 years. Compared with L′ allele carriers, those with S′S′ genotype showed higher initial symptom severity but also faster recovery rate. 5-HTTLPR genotype only predicted symptom severity at 2.5 years after the earthquake, after controlling for sex, age, ethnicity and trauma severity (β = 0.108, p = .019). This is the first evidence of the effect of 5-HTTLPR genotype on child and adolescent PTSD symptoms longitudinally, offering a novel perspective on the effect of 5-HTTLPR on PTSD symptom development following trauma exposure.     

What is an extinction burst?: A case study in the analysis of transitional behavior

Among the tactics of experimental science discussed by Sidman (1960) were those used to study transitional behavior. Drawing from his insights, this review considers an often cited but infrequently analyzed aspect of the transition from reinforcement to extinction: the extinction burst. In particular, the review seeks to answer the question posed in its title. The generic definition of an extinction burst as an increase in response rate following the onset of extinction is found to be wanting, raising more questions than it answers. Because questions of definition in science usually come down to those of measurement, the answer to the title's question is suggested to be found in how behavior prior to extinction is maintained and measured, when and how extinction is introduced, and where in time and how behavior early in extinction is measured. This analysis suggests that a single, uniform, and precise definition of the extinction burst is misguided. Examining how each of these facets contributes to what has been described generically as the extinction burst is a small, but important, part of Sidman's methodological legacy to the experimental analysis of behavior.     

Does self-compassion covary with minority stress? Examining group differences at the intersection of marginalized identities

ABSTRACT

Informed by the minority-stress hypothesis and intersectionality theory, this study examines differences in dispositional self-compassion across diverse youth subject to varying levels of structural and interpersonal discrimination. A secondary analysis of survey data from two suburban high schools in a Midwestern state (n = 1872) found significant differences in rates of exposures to stigma processes in accordance to rates of marginalization as estimated by sexual and/or gender status and racial category (minority vs majority), with a large effect. Sexual and/or gender minority students of color (SGmin) reported the highest rates of stigma experiences including exposure to economic hardship, having an incarcerated parent, not trusting the police, assignment of an IEP and exclusionary discipline. However, white SGmin students reported the highest rates of mental health concerns. Sexual gender majority (SGmaj) students of color reported the highest rates of self-compassion while white SGmin students reported the lowest and the negative relation between bullying and self-compassion was stronger for white SGmin students than for SGmin students of color, suggesting that the latter may have developed ways of coping with multiple stigmatized identities that reflect kindness to the self. As scholars seek to understand the role of self-compassion in resilience processes, we suggest emphasizing the strengths of marginalized youth as well as protecting them from the ill effects of bullying.