title: Paranoia and post-traumatic stress disorder in the months after a physical assault: a longitudinal study examining shared and differential predictors.
abstract: BACKGROUND
  Being physically assaulted is known to increase the risk of the occurrence of post-traumatic stress disorder (PTSD) symptoms but it may also skew judgements about the intentions of other people. The objectives of the study were to assess paranoia and PTSD after an assault and to test whether theory-derived cognitive factors predicted the persistence of these problems.
  
  
  METHODS
  At 4 weeks after hospital attendance due to an assault, 106 people were assessed on multiple symptom measures (including virtual reality) and cognitive factors from models of paranoia and PTSD. The symptom measures were repeated 3 and 6 months later.
  
  
  RESULTS
  Factor analysis indicated that paranoia and PTSD were distinct experiences, though positively correlated. At 4 weeks, 33% of participants met diagnostic criteria for PTSD, falling to 16% at follow-up. Of the group at the first assessment, 80% reported that since the assault they were excessively fearful of other people, which over time fell to 66%. Almost all the cognitive factors (including information-processing style during the trauma, mental defeat, qualities of unwanted memories, self-blame, negative thoughts about self, worry, safety behaviours, anomalous internal experiences and cognitive inflexibility) predicted later paranoia and PTSD, but there was little evidence of differential prediction.
  
  
  CONCLUSIONS
  Paranoia after an assault may be common and distinguishable from PTSD but predicted by a strikingly similar range of factors.
authors.affiliation: Department of Psychiatry, University of Oxford, UK.
authors.forename: D
authors.initials: D
authors.lastname: Freeman
authors.forename: C
authors.initials: C
authors.lastname: Thompson
authors.forename: N
authors.initials: N
authors.lastname: Vorontsova
authors.forename: G
authors.initials: G
authors.lastname: Dunn
authors.forename: L-A
authors.initials: LA
authors.lastname: Carter
authors.forename: P
authors.initials: P
authors.lastname: Garety
authors.forename: E
authors.initials: E
authors.lastname: Kuipers
authors.forename: M
authors.initials: M
authors.lastname: Slater
authors.forename: A
authors.initials: A
authors.lastname: Antley
authors.forename: E
authors.initials: E
authors.lastname: Glucksman
authors.forename: A
authors.initials: A
authors.lastname: Ehlers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology; D015897:Comorbidity; D019548:Crime Victims / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007398:Interpersonal Relations; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010259:Paranoid Disorders / Q000453:epidemiology* / Q000209:etiology; D011237:Predictive Value of Tests; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors; D014754:Violence / Q000523:psychology*; D055815:Young Adult