{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T07:23:07Z","timestamp":1773818587733,"version":"3.50.1"},"reference-count":47,"publisher":"Public Library of Science (PLoS)","issue":"8","license":[{"start":{"date-parts":[[2021,8,9]],"date-time":"2021-08-09T00:00:00Z","timestamp":1628467200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"department of health","award":["2010\/11 and 2014\/15 Drug Prevalence Surveys"],"award-info":[{"award-number":["2010\/11 and 2014\/15 Drug Prevalence Surveys"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background and objectives<\/jats:title>\n<jats:p>Epidemiological studies show that the use of cannabis is related to the use of other illicit drugs, including stimulants such as cocaine and ecstasy. However, few studies have examined how patterns of cannabis use relate to the use of stimulants. In this research we determined relationships between patterns of cannabis use and recent stimulant use, drawing on data from two large nationally representative surveys. We also explored how frequency of cannabis use relates to stimulant use and whether subjects with a cannabis use disorder (CUD)\u2013defined as cannabis abuse or dependence\u2013are more likely to be recent users of cocaine or ecstasy.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Materials and methods<\/jats:title>\n<jats:p>We analysed data from Ireland\u2019s 2010\/11 and 2014\/15 National Drug Prevalence Surveys,which recruited 5,134 and 7,005 individuals respectively, aged 15 years and over, living in private households. We included only those people who reported some past cannabis use. Multivariable logistic regression analysis was used to examine associations between patterns of cannabis use and recent stimulant use.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>Among survey participants who had used cannabis in the last month, 17.9% reported recent cocaine use, while almost one-quarter (23.6%) reported recent ecstasy use. There was a significant linear relationship between patterns of cannabis use and recent use of cocaine, ecstasy or any stimulant, with last month cannabis users displaying greater odds (OR = 12.03, 95% CI: 8.15\u201317.78) of having recent stimulant use compared to last year (OR = 4.48, 95% CI: 2.91\u20136.91) and former (reference) cannabis users. Greater frequency of cannabis use in the last 30 days was also significantly related to the use of stimulants. In addition, results demonstrated an association between CUD and recent use of cocaine or ecstasy (OR = 2.28, 95% CI: 1.55\u20133.35).<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>Findings from this study suggest a relationship between patterns and frequency of cannabis use and recent use of stimulants and an association between CUD and stimulant use. As the use of cannabis with stimulants may increase the risk of negative health consequences, education in community and medical settings about polydrug use and its increased risks may be warranted.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0255745","type":"journal-article","created":{"date-parts":[[2021,8,9]],"date-time":"2021-08-09T17:33:43Z","timestamp":1628530423000},"page":"e0255745","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":11,"title":["Relationships between patterns of cannabis use, abuse and dependence and recent stimulant use: Evidence from two national surveys in Ireland"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4453-8446","authenticated-orcid":true,"given":"Se\u00e1n R.","family":"Millar","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Deirdre","family":"Mongan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claire","family":"O\u2019Dwyer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bobby P.","family":"Smyth","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ivan J.","family":"Perry","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brian","family":"Galvin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2021,8,9]]},"reference":[{"key":"pone.0255745.ref001","volume-title":"The health and social effects of nonmedical cannabis use","author":"World Health Organization","year":"2016"},{"key":"pone.0255745.ref002","volume-title":"Ireland Country Drug Report 2019","author":"European Monitoring Centre for Drugs and Drug Addiction","year":"2019"},{"key":"pone.0255745.ref003","volume-title":"Focal Point Ireland: national report for 2017 \u2013drugs","author":"Health Research Board","year":"2018"},{"key":"pone.0255745.ref004","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1093\/eurpub\/ckab007","article-title":"Correlates of patterns of cannabis use, abuse and dependence: evidence from two national surveys","volume":"31","author":"SR Millar","year":"2021","journal-title":"Ireland. 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