J. Ormel

Evidence for plasticity genotypes in a gene-gene- environment interaction: the TRAILS study

The purpose was to study how functional polymorphisms in the brain derived neurotrophic factor gene (BDNF val66met) and the serotonin transporter gene linked promotor region (5‐HTTLPR) interact with childhood adversities in predicting Effortful Control. Effortful Control refers to the ability to regulate behavior in a goal‐directed manner and is an interesting endophenotype for psychopathology because of its heritability and the association of low Effortful Control with both internalizing and externalizing problems. In a longitudinal population‐based study Effortful Control was assessed with the parent version of the Early Adolescent Temperament Questionnaire at age 11. Pregnancy and delivery adversities and childhood events were assessed in a parent interview at age 11. Long‐term difficulties until age 11 were assessed with a parent questionnaire at age 13.5. Blood or buccal cells were collected at age 16 for genotyping the rs6265 and rs25531 SNPs and the 5‐HTTLPR length polymorphism. The study included 1032 complete data sets. Effortful Control was significantly predicted by the interaction between BDNF val66met, 5‐HTTLPR and childhood events. The BDNF val66met val/val–5‐HTTLPR l′/l′ genotype was unaffected by childhood events, while having either at least one BDNF val66met met or 5‐HTTLPR s′ allele (l′/l′‐met‐carrier; l′/s′‐val/val; s′/s′‐val/val) made children sensitive to childhood events. Predictions of Effortful Control by pregnancy and delivery adversities and long‐term difficulties were largely independent of genotype. We concluded that the l′/l′‐met‐carrier, l′/s′‐val/val and the s′/s′‐val/val genotypes showed greatest plasticity while the l′/l′‐val/val genotype was unaffected by childhood events.

Stressful events and temperament change during early and middle adolescence : The TRAILS study

This project investigates how stressful events are related to deviations from normative temperament development during adolescence. Temperament traits were assessed at ages 11 and 16 years. Life–event data was captured using an interview (total n = 1197). Normative changes were found in all traits. A linear trend was found between the experience of stressful events and temperament development. Adolescents exposed to stressful events showed smaller decreases in fear and shyness, stronger decreases in effortful control and affiliation and smaller increases in high intensity pleasure. Exposure to stressful events was related to increases in frustration instead of decreases. Our results show that whereas normative development is mostly in the direction of maturation, adolescents who experienced stressful events showed less maturation of their temperament. Copyright

Genetically based reduced MAOA and COMT functioning is associated with the cortisol stress response : a replication study

Genetically based reduced MAOA and COMT functioning is associated with the cortisol stress response: a replication study

Explaining heterogeneity in disability associated with current major depressive disorder: Effects of illness characteristics and comorbid mental disorders

BACKGROUND Although major depressive disorder (MDD) is associated with disability, some persons do function well despite their illness. Aim of the present study was to examine the effect of illness characteristics and comorbid mental disorders on various aspects of disability among persons with a current MDD episode. METHODS Data were derived from 607 participants with a current MDD based on the Composite International Diagnostic Interview (CIDI). Severity was assessed via the Inventory of Depressive Symptoms self-report (IDS-SR). For disability three outcome measures were used: World Health Organization Disability Assessment Schedule II (WHODAS) disability and its 7 dimensions, days out of role, and work absence. Using multiple regression analysis the effects of MDD characteristics and comorbid mental disorders were estimated. RESULTS The IDS-SR score was the best predictor of all disability outcomes. Of the comorbid mental disorders, agoraphobia was significantly associated with overall disability. Collectively, all illness characteristics accounted for 43% of variance in WHODAS disability, 13% in days out of role and 10% in work absence, suggesting substantial unexplained variance. LIMITATIONS Only self-report measures of disability were used. There were no assessments of other diagnoses than depressive, anxiety and alcohol use disorders. CONCLUSIONS Although heterogeneity in disability of persons with current MDD is partially explained by illness characteristics of MDD (especially symptom severity) and comorbid mental disorders, most of the variance is not accounted for.

Why Not Everyone Gets Their Fair Share of Stress: Adolescent's Perceived Relationship Affection Mediates Associations Between Temperament and Subsequent Stressful Social Events: Temperament and stressful social events

Temperamental differences are associated with subsequent stressful life events, a phenomenon that has in part been attributed to evocation. However, we remain ignorant about the mechanisms that mediate this process. In the current paper, we test whether differences in ‘perceived relationship affection’ accounted for part of the prospective association between temperament and stressful social event evocation in three social domains, viz. parents, peers and romantic partners. Data were derived from the Tracking Adolescents’ Individual Lives Survey, a large population cohort of Dutch adolescents (n = 1158). Parent–reported adolescent temperament and adolescents perceived affection were assessed at age 11 years. Stressful social events that occurred between age 11 and 16 years were captured using the event history calendar. Results indicate that adolescents evoke subsequent stressful social events based on their temperament, and that this association is partially mediated by perceived affection. Importantly, we found evidence for both generic and domain–specific associations, which indicates that social domains are related yet distinct. Taken together, the findings suggest that a search for mediating variables may be a promising way to increase our understanding of the mechanisms that underlie the social stress selection principle, and that perceived relationship affection is one of the candidates. Copyright

Stressful Events and Temperament Change during Early and Middle Adolescence: The TRAILS Study: Stressful events and temperament change

This project investigates how stressful events are related to deviations from normative temperament development during adolescence. Temperament traits were assessed at ages 11 and 16 years. Life–event data was captured using an interview (total n = 1197). Normative changes were found in all traits. A linear trend was found between the experience of stressful events and temperament development. Adolescents exposed to stressful events showed smaller decreases in fear and shyness, stronger decreases in effortful control and affiliation and smaller increases in high intensity pleasure. Exposure to stressful events was related to increases in frustration instead of decreases. Our results show that whereas normative development is mostly in the direction of maturation, adolescents who experienced stressful events showed less maturation of their temperament. Copyright