title: Estrogen levels are associated with extinction deficits in women with posttraumatic stress disorder.
abstract: BACKGROUND
  Women are twice as likely to develop posttraumatic stress disorder (PTSD) than men. As shown in our previous work, the inability to suppress fear responses in safe conditions may be a biomarker for PTSD. Low estrogen in naturally cycling women is associated with deficits in fear extinction. On the basis of these findings, we have now examined the influence of estrogen levels on fear extinction in women with and without PTSD.
  
  
  METHODS
  We measured fear-potentiated startle during fear conditioning and extinction in women. The study sample (N = 81) was recruited from an urban, highly traumatized civilian population at Grady Memorial Hospital in Atlanta, Georgia. We assayed serum estrogen levels and used a median split to divide the sample into high and low estradiol (E(2)) groups. Seventeen of 41 women (41.5%) in the low E(2) group and 15 of 40 women (37.5%) met criteria for PTSD in the high E(2) group.
  
  
  RESULTS
  The results showed that all groups had equivalent levels of fear conditioning. However, we found significant interaction effects between high versus low E(2) groups and PTSD diagnosis [F(1,71) = 4.55, p < .05] on extinction. Among women with low estrogen levels, fear-potentiated startle was higher during extinction in the PTSD group compared with traumatized control women [F(1,38) = 5.04, p < .05]. This effect was absent in the High E(2) group.
  
  
  CONCLUSIONS
  This study suggests that low estrogen may be a vulnerability factor for development of PTSD in women with trauma histories. Research on the role of estrogen in fear regulation may provide insight into novel treatment strategies for PTSD.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia 30303, USA. eglover@emory.edu
authors.forename: Ebony M
authors.initials: EM
authors.lastname: Glover
authors.forename: Tanja
authors.initials: T
authors.lastname: Jovanovic
authors.forename: Kristina B
authors.initials: KB
authors.lastname: Mercer
authors.forename: Kimberly
authors.initials: K
authors.lastname: Kerley
authors.forename: Bekh
authors.initials: B
authors.lastname: Bradley
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Ressler
authors.forename: Seth D
authors.initials: SD
authors.lastname: Norrholm
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004967:Estrogens / Q000097:blood*; D005108:Extinction, Psychological; D005239:Fear / Q000523:psychology*; D005260:Female; D005845:Georgia; D006801:Humans; D008875:Middle Aged; D013216:Reflex, Startle; D013313:Stress Disorders, Post-Traumatic / Q000097:blood* / Q000523:psychology*; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D004967:Estrogens