title: Gender differences in posttraumatic stress disorder among primary care patients after the World Trade Center attack of September 11, 2001.
abstract: BACKGROUND
  Debate surrounds the nature of gender differences in rates of posttraumatic stress disorder (PTSD).
  
  
  OBJECTIVE
  The goal of this study was to quantify and explore the reasons for gender differences in rates of PTSD in low income, primary care patients after the World Trade Center (WTC) attack of September 11, 2001.
  
  
  METHODS
  A survey was conducted at a large primary care practice in New York City 7 to 16 months after the WTC attack. The study involved a systematic sample of primary care patients aged 18 to 70 years. The main outcome measures were the Life Events Checklist, the Posttraumatic Stress Disorder Checklist-Civilian Version, and the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire, all administered by a bilingual research staff.
  
  
  RESULTS
  A total of 3807 patients were approached at the primary care clinic. Of the 1347 who met eligibility criteria, 1157 (85.9%) consented to participate. After the addition of the WTC/PTSD supplement to the study, the total number of patients was 992, of whom 982 (99.0%) completed the survey. Both sexes had high rates of direct exposure to the WTC attack and high rates of lifetime exposure to stressful life events. Overall, females had lower rates of exposure to the attack compared with males (P < 0.05). Hispanic females had the highest rate of PTSD in the full sample. Gender differences in rates of PTSD were largely accounted for by differences in marital status and education. The rate of current major depressive disorder (MDD) was higher in females than in males (P < 0.001), and the reverse was true for substance abuse (P < 0.001). Gender differences for MDD and substance abuse persisted even after adjustments for demographic differences between the sexes.
  
  
  CONCLUSIONS
  The increased rate of PTSD in women attending a primary care clinic was mediated by their social and economic circumstances, such as living alone without a permanent relationship and with little education or income. The increased rate of MDD in women appeared to be less dependent on these circumstances. These findings have implications for the treatment of women with PTSD in primary care and for research on gender differences in rates of psychiatric disorders.
authors.affiliation: Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA. mmw3@columbia.edu
authors.forename: Myrna M
authors.initials: MM
authors.lastname: Weissman
authors.forename: Yuval
authors.initials: Y
authors.lastname: Neria
authors.forename: Amar
authors.initials: A
authors.lastname: Das
authors.forename: Adriana
authors.initials: A
authors.lastname: Feder
authors.forename: Carlos
authors.initials: C
authors.lastname: Blanco
authors.forename: Rafael
authors.initials: R
authors.lastname: Lantigua
authors.forename: Steven
authors.initials: S
authors.lastname: Shea
authors.forename: Raz
authors.initials: R
authors.lastname: Gross
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Gameroff
authors.forename: Daniel
authors.initials: D
authors.lastname: Pilowsky
authors.forename: Mark
authors.initials: M
authors.lastname: Olfson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D011320:Primary Health Care / Q000706:statistics & numerical data; D012307:Risk Factors; D017678:Sex Distribution; D012737:Sex Factors; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology* / Q000208:ethnology / Q000523:psychology; D023481:Terrorism / Q000523:psychology*; D014930:Women / Q000523:psychology*