eprintid: 10093869 rev_number: 27 eprint_status: archive userid: 608 dir: disk0/10/09/38/69 datestamp: 2020-03-24 11:50:30 lastmod: 2022-11-04 14:36:53 status_changed: 2020-03-24 11:50:30 type: article metadata_visibility: show creators_name: Lewis, G creators_name: Dykxhoorn, J creators_name: Karlsson, H creators_name: Khandaker, GM creators_name: Lewis, G creators_name: Dalman, C creators_name: Kirkbride, JB title: Assessment of the Role of IQ in Associations Between Population Density and Deprivation and Nonaffective Psychosis ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D79 divisions: D12 divisions: G20 note: This is an open access article distributed under the terms of the CC-BY License (https://jamanetwork.com/journals/jamapsychiatry/pages/instructions-for-authors#SecOpenAccess). Copyright © 2020 Lewis G et al. JAMA Psychiatry. abstract: Importance: Being born or raised in more densely populated or deprived areas is associated with increased risk of nonaffective psychosis in adulthood, but few studies to date have examined the role of general cognitive ability in these associations. / Objective: To investigate whether lower IQ contributed to the association between population density or deprivation and nonaffective psychosis (mediation) and whether these associations were stronger in people with lower IQ (effect modification). / Design, Setting, and Participants: This prospective cohort study evaluated a population-based sample of men born in Sweden from January 1, 1982, to December 31, 1988, and conscripted into military service at 18 years of age. Data were collected from January 1, 1982, to December 31, 2016, and analyzed from May 1 to December 31, 2018. / Exposures: Continuous measures of small area-level population density (persons per square kilometer) and socioeconomic deprivation at birth. Deprivation was based on area-level social, criminal, and unemployment data. IQ was assessed during conscription at 18 years of age (mean [SD] IQ, 100 [15]). / Main Outcomes and Measures: First diagnosis of International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, nonaffective psychosis from 18 years of age until December 31, 2016, recorded in the National Patient Register. / Results: The study sample included a total of 227 429 men who were classified as at risk of psychosis from 18 years of age until the end of follow-up. Of these, 1596 men (0.7%) were diagnosed with nonaffective psychosis. After adjustments for confounders, odds of nonaffective psychosis increased per 1-SD increase in population density (odds ratio [OR], 1.07; 95% CI, 1.04-1.14) and deprivation (OR, 1.09; 95% CI, 1.02-1.13) at birth. IQ was negatively associated with deprivation after adjustments (effect estimate per 1-SD increase in deprivation: -0.70 points; 95% CI, -0.78 to -0.62 points) but not with population density. In mediation analyses, based on the potential outcome framework, 23% (95% CI, 17%-49%) of the total effect of deprivation on nonaffective psychosis was mediated by IQ. IQ did not modify associations between deprivation or population density and nonaffective psychosis. / Conclusions and Relevance: These findings suggest that being born in more deprived neighborhoods may partly increase risk of nonaffective psychosis through subsequent effects on cognitive development, consistent with the wider literature on neurodevelopmental delays associated with psychotic disorder. Identifying factors in deprived environments that give rise to this process could inform public health strategies to prevent nonaffective psychosis. date: 2020-03-11 date_type: published official_url: https://doi.org/10.1001/jamapsychiatry.2020.0103 oa_status: green full_text_type: pub pmcid: PMC7066518 language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1773394 doi: 10.1001/jamapsychiatry.2020.0103 pii: 2762528 lyricists_name: Dykxhoorn, Jennifer lyricists_name: Kirkbride, James lyricists_name: Lewis, Gemma lyricists_name: Lewis, Glyn lyricists_id: JLDYK14 lyricists_id: JBKIR68 lyricists_id: GLEWI99 lyricists_id: GHLEW69 actors_name: Kirkbride, James actors_id: JBKIR68 actors_role: owner full_text_status: public publication: JAMA Psychiatry volume: 77 number: 7 pagerange: 729-736 event_location: United States citation: Lewis, G; Dykxhoorn, J; Karlsson, H; Khandaker, GM; Lewis, G; Dalman, C; Kirkbride, JB; (2020) Assessment of the Role of IQ in Associations Between Population Density and Deprivation and Nonaffective Psychosis. JAMA Psychiatry , 77 (7) pp. 729-736. 10.1001/jamapsychiatry.2020.0103 <https://doi.org/10.1001/jamapsychiatry.2020.0103>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10093869/1/Lewis%20et%20al.%20-%202020%20-%20JAMA%20Psychiatry.pdf