eprintid: 10072189
rev_number: 33
eprint_status: archive
userid: 608
dir: disk0/10/07/21/89
datestamp: 2019-04-15 15:45:26
lastmod: 2021-09-19 23:52:01
status_changed: 2019-04-15 15:45:26
type: article
metadata_visibility: show
creators_name: Di Forti, M
creators_name: Quattrone, D
creators_name: Freeman, TP
creators_name: Tripoli, G
creators_name: Gayer-Anderson, C
creators_name: Quigley, H
creators_name: Rodriguez, V
creators_name: Jongsma, HE
creators_name: Ferraro, L
creators_name: La Cascia, C
creators_name: La Barbera, D
creators_name: Tarricone, I
creators_name: Berardi, D
creators_name: Szöke, A
creators_name: Arango, C
creators_name: Tortelli, A
creators_name: Velthorst, E
creators_name: Bernardo, M
creators_name: Del-Ben, CM
creators_name: Menezes, PR
creators_name: Selten, J-P
creators_name: Jones, PB
creators_name: Kirkbride, JB
creators_name: Rutten, BP
creators_name: de Haan, L
creators_name: Sham, PC
creators_name: van Os, J
creators_name: Lewis, CM
creators_name: Lynskey, M
creators_name: Morgan, C
creators_name: Murray, RM
creators_name: EU-GEI WP2 Group, .
title: The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study
ispublished: inpress
divisions: UCL
divisions: B16
divisions: B14
divisions: J81
divisions: B02
divisions: C07
divisions: D05
divisions: F66
divisions: D79
note: © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/).
abstract: BACKGROUND: Cannabis use is associated with increased risk of later psychotic disorder but whether it affects incidence of the disorder remains unclear. We aimed to identify patterns of cannabis use with the strongest effect on odds of psychotic disorder across Europe and explore whether differences in such patterns contribute to variations in the incidence rates of psychotic disorder. METHODS: We included patients aged 18–64 years who presented to psychiatric services in 11 sites across Europe and Brazil with first-episode psychosis and recruited controls representative of the local populations. We applied adjusted logistic regression models to the data to estimate which patterns of cannabis use carried the highest odds for psychotic disorder. Using Europe-wide and national data on the expected concentration of Δ⁹ -tetrahydrocannabinol (THC) in the different types of cannabis available across the sites, we divided the types of cannabis used by participants into two categories: low potency (THC <10%) and high potency (THC ≥10%). Assuming causality, we calculated the population attributable fractions (PAFs) for the patterns of cannabis use associated with the highest odds of psychosis and the correlation between such patterns and the incidence rates for psychotic disorder across the study sites. FINDINGS: Between May 1, 2010, and April 1, 2015, we obtained data from 901 patients with first-episode psychosis across 11 sites and 1237 population controls from those same sites. Daily cannabis use was associated with increased odds of psychotic disorder compared with never users (adjusted odds ratio [OR] 3·2, 95% CI 2·2–4·1), increasing to nearly five-times increased odds for daily use of high-potency types of cannabis (4·8, 2·5–6·3). The PAFs calculated indicated that if high-potency cannabis were no longer available, 12·2% (95% CI 3·0–16·1) of cases of first-episode psychosis could be prevented across the 11 sites, rising to 30·3% (15·2–40·0) in London and 50·3% (27·4–66·0) in Amsterdam. The adjusted incident rates for psychotic disorder were positively correlated with the prevalence in controls across the 11 sites of use of high-potency cannabis (r = 0·7; p=0·0286) and daily use (r = 0·8; p=0·0109). INTERPRETATION: Differences in frequency of daily cannabis use and in use of high-potency cannabis contributed to the striking variation in the incidence of psychotic disorder across the 11 studied sites. Given the increasing availability of high-potency cannabis, this has important implications for public health. FUNDING SOURCE: Medical Research Council, the European Community's Seventh Framework Program grant, São Paulo Research Foundation, National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust and King's College London and the NIHR BRC at University College London, Wellcome Trust.
date: 2019-03-19
date_type: published
official_url: https://doi.org/10.1016/S2215-0366(19)30048-3
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
article_type_text: Journal Article
verified: verified_manual
elements_id: 1645053
doi: 10.1016/S2215-0366(19)30048-3
pii: S2215-0366(19)30048-3
language_elements: English
lyricists_name: Freeman, Tom
lyricists_name: Jongsma, Hannah
lyricists_name: Kirkbride, James
lyricists_id: TPFRE38
lyricists_id: HJJON41
lyricists_id: JBKIR68
actors_name: Kirkbride, James
actors_id: JBKIR68
actors_role: owner
full_text_status: public
publication: The Lancet Psychiatry
event_location: England
issn: 2215-0374
citation:        Di Forti, M;    Quattrone, D;    Freeman, TP;    Tripoli, G;    Gayer-Anderson, C;    Quigley, H;    Rodriguez, V;                                                                                                     ... EU-GEI WP2 Group, .; + view all <#>        Di Forti, M;  Quattrone, D;  Freeman, TP;  Tripoli, G;  Gayer-Anderson, C;  Quigley, H;  Rodriguez, V;  Jongsma, HE;  Ferraro, L;  La Cascia, C;  La Barbera, D;  Tarricone, I;  Berardi, D;  Szöke, A;  Arango, C;  Tortelli, A;  Velthorst, E;  Bernardo, M;  Del-Ben, CM;  Menezes, PR;  Selten, J-P;  Jones, PB;  Kirkbride, JB;  Rutten, BP;  de Haan, L;  Sham, PC;  van Os, J;  Lewis, CM;  Lynskey, M;  Morgan, C;  Murray, RM;  EU-GEI WP2 Group, .;   - view fewer <#>    (2019)    The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study.                   The Lancet Psychiatry        10.1016/S2215-0366(19)30048-3 <https://doi.org/10.1016/S2215-0366%2819%2930048-3>.    (In press).    Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10072189/1/Kirkbride_The%20contribution%20of%20cannabis%20use%20to%20variation%20in%20the%20incidence%20of%20psychotic%20disorder%20across%20Europe%20%28EU-GEI%29_Proof.pdf