Lack of association between the 5-HTTLPR and positive screening for mental disorders among children exposed to urban violence and maltreatment

5-HTTLPR-brain-derived neurotrophic factor (BDNF) gene interactions and early adverse life events effect on impulsivity in suicide attempters

OBJECTIVES

An expanding body of research suggests that childhood adverse experiences can lead to different negative health outcomes, including attempted suicide. Serotonergic genes such as the promoter region of the serotonin transporter gene (5-HTTLPR) have been associated both with impulsivity in suicide attempts and reactivity to environmental stress exposure. BDNF gene may play an epigenetic role.

METHODS

We studied the influence of childhood stressful events and 5-HTTLPR genotype on impulsivity measured by Barratt Impulsivity Scale (BIS-10) in a multicentre sample of 1,655 suicide attempters (69.4% women, 30.6% men; mean age 40.13 years). A co-dominant additive genetic model was used for the statistical analyses. Interaction between 5-HTTLPR genotype and early trauma exposure was tested using moderated and multiple regression techniques. Interaction plots were used to explore BDNF genotype modulation.

RESULTS

Mildly higher impulsivity scores were found in men with SS compared with SL or LL genotypes, and men with childhood emotional and physical abuse. Interaction analyses showed that combination of 5-HTTLPR-SS genotype and early trauma exposure increase impulsivity scores independently. Impulsivity scores were not affected by the modulation of BDNF genes.

CONCLUSIONS

Childhood trauma and 5-HTTLPR genotype seem to be independently involved in suicide attempts, sharing a common pathway of increasing impulsivity.

Influence of 5-HTT variation, childhood trauma and self-efficacy on anxiety traits: a gene-environment-coping interaction study

Environmental vulnerability factors such as adverse childhood experiences in interaction with genetic risk variants, e.g., the serotonin transporter gene linked polymorphic region (5-HTTLPR), are assumed to play a role in the development of anxiety and affective disorders. However, positive influences such as general self-efficacy (GSE) may exert a compensatory effect on genetic disposition, environmental adversity, and anxiety traits. We, thus, assessed childhood trauma (Childhood Trauma Questionnaire, CTQ) and GSE in 678 adults genotyped for 5-HTTLPR/rs25531 and their interaction on agoraphobic cognitions (Agoraphobic Cognitions Questionnaire, ACQ), social anxiety (Liebowitz Social Anxiety Scale, LSAS), and trait anxiety (State-Trait Anxiety Inventory, STAI-T). The relationship between anxiety traits and childhood trauma was moderated by self-efficacy in 5-HTTLPR/rs25531 LALA genotype carriers: LALA probands maltreated as children showed high anxiety scores when self-efficacy was low, but low anxiety scores in the presence of high self-efficacy despite childhood maltreatment. Our results extend previous findings regarding anxiety-related traits showing an interactive relationship between 5-HTT genotype and adverse childhood experiences by suggesting coping-related measures to function as an additional dimension buffering the effects of a gene-environment risk constellation. Given that anxiety disorders manifest already early in childhood, this insight could contribute to the improvement of psychotherapeutic interventions by including measures strengthening self-efficacy and inform early targeted preventive interventions in at-risk populations, particularly within the crucial time window of childhood and adolescence.