Interactive effect of stressful life events and the serotonin transporter 5-HTTLPR genotype on posttraumatic stress disorder diagnosis in 2 independent populations - PubMed (original) (raw)

Comparative Study

Interactive effect of stressful life events and the serotonin transporter 5-HTTLPR genotype on posttraumatic stress disorder diagnosis in 2 independent populations

Pingxing Xie et al. Arch Gen Psychiatry. 2009 Nov.

Abstract

Context: The 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene (SLC6A4) has been found to moderate several categories of emotional response after stressful life events. Previous studies generally focused on its effect on depressive symptoms; little is known about its moderation of the development of posttraumatic stress disorder (PTSD).

Objective: To examine the effects of childhood adversity, adult traumatic events, 5-HTTLPR genotypes, and gene x environment interactions on the etiology of PTSD.

Design: A cross-sectional study in which participants in several studies investigating the genetics of substance dependence were also screened for lifetime PTSD. The triallelic system of 5-HTTLPR was genotyped. Logistic regression modeling was used in the analyses.

Setting: General community.

Participants: Five hundred eighty-two European American and 670 African American individuals who reported experiences of childhood adversity, adult traumatic events, or both. Main Outcome Measure Diagnosis of PTSD, defined by DSM-IV diagnostic criteria and assessed through the Semi-Structured Assessment for Drug Dependence and Alcoholism interview.

Results: Childhood adversity and adult traumatic events both predicted PTSD. Although the 5-HTTLPR genotype alone did not predict the onset of PTSD, it interacted with adult traumatic events and childhood adversity to increase the risk for PTSD, especially for those with high rates of both types of trauma exposure (European American: odds ratio [OR], 2.86; 95% confidence interval [CI], 1.50-5.45; P = .002; African American: OR, 1.88; 95% CI, 1.04-3.40; P = .04; pooled: OR, 2.31; 95% CI, 1.50-3.56; P < .001).

Conclusions: Participants who had both childhood adversity and adult traumatic events were more likely to develop lifetime PTSD compared with those who experienced either type of adverse event. The risk was increased in individuals with 1 or 2 copies of the S' (S) allele compared with the L' (L) homozygotes. Our study provides additional direct evidence that PTSD is influenced by the interactive effect of environmental and genetic factors.

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Figures

Figure 1

Figure 1

The number of childhood adversity types is associated with the onset of posttraumatic stress disorder (PTSD).

Figure 2

Figure 2

In European American and African American individuals, 5-HTTLPR genotype interacted with adult traumatic events (A and B) to increase risk for posttraumatic stress disorder (PTSD). In European American individuals, the genotype also interacted with childhood adversity (C); in African American individuals, the interactive effect was a trend (D). The numbers of patients with PTSD of the total numbers of participants in the group are shown.

Figure 3

Figure 3

5-HTTLPR genotype interacted with dual stressful life events to increase the risk for posttraumatic stress disorder (PTSD) in both European American and African American individuals. The numbers of patients with PTSD of the total numbers of participants in the group are shown.

Figure 4

Figure 4

5-HTTLPR genotype interacted with the number of stressful life events to increase the risk for posttraumatic stress disorder (PTSD) (group 1: exposure to either adult trauma or childhood adversity; group 2: exposure to adult trauma and 1 type of childhood adversity; group 3: exposure to adult trauma and 2 types of childhood adversity; and group 4: exposure to adult trauma and more than 2 types of childhood adversity).

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References

    1. Breslau N, Davis GC, Andreski P, Peterson E. Traumatic events and posttraumatic stress disorder in an urban population of young adults. Arch Gen Psychiatry. 1991;48(3):216–222. - PubMed
    1. Norris FH. Epidemiology of trauma: frequency and impact of different potentially traumatic events on different demographic groups. J Consult Clin Psychol. 1992;60(3):409–418. - PubMed
    1. Kessler RC, Sonnega A, Bromet E, Hughes M, Nelson CB. Posttraumatic stress disorder in the National Comorbidity Survey. Arch Gen Psychiatry. 1995;52(12):1048–1060. - PubMed
    1. Bromet E, Sonnega A, Kessler RC. Risk factors for DSM-III-R posttraumatic stress disorder: findings from the National Comorbidity Survey. Am J Epidemiol. 1998;147(4):353–361. - PubMed
    1. Bramsen I, Dirkzwager AJ, van der Ploeg HM. Predeployment personality traits and exposure to trauma as predictors of posttraumatic stress symptoms: a prospective study of former peacekeepers. Am J Psychiatry. 2000;157(7):1115–1119. - PubMed

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