The serotonin transporter genotype and social support and moderation of posttraumatic stress disorder and depression in hurricane-exposed adults.
OBJECTIVE
Disasters are associated with increased risk of posttraumatic stress disorder (PTSD) and major depression, but no study, to the authors' knowledge, has determined whether genotype interacts with disaster exposure and social support to moderate risk of these phenotypes. The authors tested the hypothesis that a polymorphism in the serotonin transporter gene (locus, SLC6A4; variant, serotonin 5-HTTLPR) moderates risk of posthurricane PTSD and major depression given high hurricane exposure and low social support.


METHODS
The authors interviewed a household probability sample of adults 6-9 months after the 2004 hurricanes about hurricane exposure, social support, and posthurricane PTSD and major depression. DNA was collected from a subset of participants. Participants were 589 adults ages 18 and older from 38 Florida counties who provided valid DNA samples. Outcome measures were DSM-IV diagnoses of posthurricane PTSD and major depression derived from structured interviews.


RESULTS
The low-expression variant of the 5-HTTLPR polymorphism increased risk of posthurricane PTSD and major depression but only under the conditions of high hurricane exposure and low social support after adjustment for sex, ancestry (as determined by Bayesian clustering of genotypes), and age. Similar effects were found for major depression. High-risk individuals (high hurricane exposure, the low-expression 5-HTTLPR variant, low social support) were at 4.5 times the risk of developing PTSD and major depression of low-risk individuals.


CONCLUSIONS
The low-expression variant of the 5-HTTLPR polymorphism modifies risk of postdisaster PTSD and major depression under conditions of high hurricane exposure and low social support, confirming and extending previous research.
Kilpatrick
Dean G
DG
National Crime Victims Research and Treatment Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, P.O. Box 250852, Charleston, SC 29425, USA. kilpatdg@musc.edu
Koenen
Karestan C
KC
Ruggiero
Kenneth J
KJ
Acierno
Ron
R
Galea
Sandro
S
Resnick
Heidi S
HS
Roitzsch
John
J
Boyle
John
J
Gelernter
Joel
J
D000293:Adolescent; D000328:Adult; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004190:Disasters; D005260:Female; D005431:Florida / Q000453:epidemiology; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008016:Life Change Events; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012307:Risk Factors; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012944:Social Support; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000453:epidemiology*
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins