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(2016 APR) : Serotonin transporter polymorphism (5HTTLPR), severe childhood abuse and depressive symptom trajectories in adulthood
Timothy B. Nguyen, Jane M. Gunn, Maria Potiriadis, Ian P. Everall, Chad A. Bousman
British Journal of Psychiatry Open Sep 2015, 1 (1) 104-109; DOI: 10.1192/bjpo.bp.115.000380
In collaboration with the Department of General Practice at The University of Melbourne, clinical and genetic data from 333 adult primary care attendees of European decent was used to examine whether the serotonin transporter polymorphism (5HTTLPR) moderated the effect childhood abuse has on five-year depressive symptom severity trajectories in adulthood.
Among the s/s group, those with a history of severe, child abuse had a mean PHQ-9 score greater than 10 (i.e. moderate depression) at each time point over the 5-year period, whereas those without a history of child abuse consistently scored under 10 (i.e. mild depression), a differential effect not observed among s/l and l/l genotype carriers. Furthermore, among individuals without a history of severe child abuse, we detected a trend in which s/s genotype carriers had more favourable depressive symptom trajectories compared with s/l and l/lgenotype carriers. This pattern of results suggests that the 5HTTLPR polymorphism may be a marker of 'phenotypic plasticity' rather than 'vulnerability' in that s/s carriers appear to be the most susceptible to the negative effects of severe child abuse (i.e. increased depressive symptom severity) but also marginally more likely to benefit from the absence of a severe child abuse experience.
Figure: Points are observed mean PHQ-9 scores with standard error bars. Lines are predicted values with 95% confidence intervals shaded based on linear mixed model analysis. Dashed line/circles=no history of severe child abuse; solid line/squares= history of severe child abuse; PHQ-9, Primary Care Evaluation of Mental Disorders Patient Health Questionnaire-9; pU, covariate-unadjuste