Social adversity, the serotonin transporter (5-HTTLPR) polymorphism and major depressive disorder.
BACKGROUND
Recent evidence has suggested that the short allele of the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR of the human serotonin gene [SLC6A4]) is associated with increased risk of depressive disorder but only among individuals exposed to social adversity. We report an investigation designed to replicate this finding.


METHODS
Data were available from a non-clinical sample of 4,175 adult men and women, ages 41-80 years, selected from participants in the European Prospective Investigation into Cancer and Nutrition in Norfolk (EPIC-Norfolk, United Kingdom) study. Evidence of past-year prevalent episodic major depressive disorder (MDD), defined by restricted DSM-IV diagnostic criteria, was assessed through questionnaire. Adverse experiences in childhood and in adulthood (during the five years preceding assessment) were also assessed through self-report. The 5-HTTLPR variant was genotyped according to published protocols.


RESULTS
One-year prevalent MDD criteria were met by 298 study participants. The experience of social adversity (both in childhood and adulthood) was strongly associated with increased rates of past-year prevalent MDD. No gene by environment (GxE) interactions between the 5-HTTLPR genotype, social adversity, and MDD were observed.


CONCLUSIONS
This study has not replicated a previous finding of a GxE interaction between the 5-HTTLPR genotype, social adversity, and depression.
Surtees
Paul G
PG
Strangeways Research Laboratory and University of Cambridge Department of Public Health and Primary Care, Worts Causeway, Cambridge, UK. paul.surtees@srl.cam.ac.uk
Wainwright
Nicholas W J
NW
Willis-Owen
Saffron A G
SA
Luben
Robert
R
Day
Nicholas E
NE
Flint
Jonathan
J
D000328:Adult; D000368:Aged; D003865:Major Depressive Disorder / Q000235:genetics*; D004739:England; D005060:Europe; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D018570:Risk Assessment; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012931:Social Environment
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins