The BDNF Val(66)Met x 5-HTTLPR x child adversity interaction and depressive symptoms: An attempt at replication

Kaufman et al. [2006] reported a higher order interaction effect between specific genetic and environmental factors in a model of depressive symptoms, requiring independent replication. BDNF Val(66)Met and 5-HTTLPR genotypes were determined in female participants pertaining to a large ongoing twin study. Participants also filled in questionnaires on childhood adversity and depressive symptoms. Two- and three-way interactions between genetic polymorphisms and early adversity were examined in models of depressive symptoms. BDNF Met allele(s) moderated the effect of early adversity on depressive symptoms (two-way interaction), and this BDNF Met x childhood adversity interaction in turn was moderated by 5-HTTLPR genotype (three-way interaction). However, a main effect of BDNF Met on childhood adversity was also observed, possibly indicating confounding by gene-environment correlation. Higher order interaction effects involving BDNF Val(66)Met, 5-HTTLPR and childhood adversity may contribute to the etiology of depressive illness.status: publishe

Evidence for a relationship between mentalising deficits and paranoia over the psychosis continuum

Failing of mentalising has been suggested to underlie certain symptoms of psychosis. An as yet unresolved issue is whether mentalising deficits reflect a characteristic which can also be detected in people at risk for psychosis or people with evidence of subclinical expression of psychosis. This study wanted to assess an aspect of mentalising in four groups with different levels of psychosis vulnerability, and to examine associations between mentalising and symptoms of psychosis.status: publishe

Childhood negative experiences and subclinical psychosis in adolescence: a longitudinal general population study

© 2007 The Authors. Background: Accumulating evidence suggests that experiences of trauma and victimization during childhood are associated with an increased risk to develop clinical and subclinical psychosis in adulthood. A recent cross-sectional study showed a significant association between trauma and psychotic experiences in adolescents. The current study aimed to extend these findings by investigating the longitudinal effects of negative life experiences on the risk for subclinical psychotic symptoms 2 years later in an adolescent general community sample. Methods: Data were derived from the standard health screenings of the Youth Health Care Divisions of the Public Health Services, in the South of the Netherlands. A total of 1129 adolescents filled out a self-report questionnaire at age 13/14 years and 2 years later (15/16 years), assessing psychotic experiences, as well as experiences of being bullied, sexual trauma, and negative life events. Results: Logistic regression analyses revealed that sexual trauma increased the risk for psychotic symptoms 2 years later. Life events contributed to the risk for psychosis over time and psychosis in turn gave rise to new life events. No significant association with bullying was found after controlling for confounders. Conclusion: The results provide further evidence for an association between childhood environment and psychosis in the crucial developmental period of early adolescence. Early and later psychological stress, if severe, may impact on the risk for psychosis in adolescence through mechanisms of person-environment interaction and correlation.status: publishe

Impairment of self-monitoring: part of the endophenotypic risk for psychosis

A disorder of self-monitoring may underlie the positive symptoms of psychosis. The cognitive mechanisms associated with these symptoms may also be detectable in individuals at risk of psychosis.status: publishe

Susceptibility to depression expressed as alterations in cortisol day curve: a cross-twin, cross-trait study

OBJECTIVE: To examine, using a cross-twin cross-trait design, the hypotheses 1) that the genetic and environmental susceptibility to depression is expressed, in part, as alterations in cortisol day curves and 2) that cortisol abnormalities are not merely the consequence of depressive states or the stressors associated with its onset. Alteration of diurnal secretion of cortisol is a possible endophenotype of depression, as depressed patients show alterations in cortisol dynamics over the day. METHODS: Salivary cortisol measurements were obtained in a sample of 279 twin pairs at 10 random times a day for 5 days. A structured clinical interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) axis I mood disorder (SCID) was administered. Using multilevel regression analysis, the moderating influence of a lifetime diagnosis of depression in the co-twin on the association between time of day and cortisol concentrations in the proband twin was examined. RESULTS: Diurnal variation in cortisol in the proband twin differed as a function of lifetime diagnosis of depression in the co-twin. In addition, this moderating effect was significantly stronger for dizygotic than for monozygotic twins. CONCLUSIONS: Probands of co-twins with lifetime depression have a different diurnal cortisol profile than those without, suggesting that altered hypothalamic-pituitary-adrenal axis functioning is an indicator of depression susceptibility.status: publishe