title: The Stress of the Street for Patients With Persecutory Delusions: A Test of the Symptomatic and Psychological Effects of Going Outside Into a Busy Urban Area.
abstract: BACKGROUND
  For many patients with persecutory delusions, leaving home and going into crowded streets is a key clinical problem. In this study we aimed to inform treatment development by determining the psychological mechanisms whereby busy urban environments increase paranoia. In a randomized design with prespecified mediation analysis, we compared the effects on patients of going outside into a busy social environment with staying inside.
  
  
  METHODS
  Fifty-nine patients with current persecutory delusions, in the context of nonaffective psychosis, reporting fears when going outside were assessed on factors from a cognitive model of paranoia. They were then randomized either to enter a busy local shopping street or to complete a neutral task indoors. They were then reassessed on the measures.
  
  
  RESULTS
  Compared with staying inside, the street exposure condition resulted in significant increases in paranoia, voices, anxiety, negative beliefs about the self, and negative beliefs about others. There was also a decrease in positive thoughts about the self. There was no alteration in reasoning processes. There were indications that the increase in paranoia was partially mediated by increases in anxiety (45%), depression (38%), and negative beliefs about others (45%).
  
  
  CONCLUSIONS
  We found that increases in negative affect may form an important route by which social exposure in urban environments triggers paranoid thoughts. The study provides an illustration of how an experimental approach can be applied to help understand a specific difficulty for patients with psychosis. In future studies the effects of specific elements of the social environment could be tested.
authors.affiliation: Department of Psychiatry, University of Oxford, Oxford, UK; daniel.freeman@psych.ox.ac.uk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Freeman
authors.affiliation: Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK;
authors.forename: Richard
authors.initials: R
authors.lastname: Emsley
authors.affiliation: Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK;
authors.forename: Graham
authors.initials: G
authors.lastname: Dunn
authors.affiliation: School of Psychology, University of Sussex, Sussex, UK;
authors.forename: David
authors.initials: D
authors.lastname: Fowler
authors.affiliation: Department of Psychiatry, Faculty of Brain Sciences, University College London, UK;
authors.forename: Paul
authors.initials: P
authors.lastname: Bebbington
authors.affiliation: Department of Psychology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK; BRC of the South London and Maudsley NHS Foundation Trust, London UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kuipers
authors.affiliation: Department of Psychology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK;
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jolley
authors.affiliation: Department of Psychology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK;
authors.forename: Helen
authors.initials: H
authors.lastname: Waller
authors.affiliation: Department of Psychology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK;
authors.forename: Amy
authors.initials: A
authors.lastname: Hardy
authors.affiliation: Department of Psychology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK; BRC of the South London and Maudsley NHS Foundation Trust, London UK.
authors.forename: Philippa
authors.initials: P
authors.lastname: Garety
mesh_terms: D000328:Adult; D001007:Anxiety / Q000503:physiopathology / Q000523:psychology; D003702:Delusions / Q000503:physiopathology* / Q000523:psychology; D003863:Depression / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010259:Paranoid Disorders / Q000503:physiopathology* / Q000523:psychology; D010865:Pilot Projects; D011618:Psychotic Disorders / Q000503:physiopathology* / Q000523:psychology; D011897:Random Allocation; D012931:Social Environment; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology
keywords: anxiety; delusions; depression; paranoia; urbanicity