Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

Marta Di Forti; Hannah Sallis; Fabio Allegri; Antonella Trotta; Laura Ferraro; Simona A Stilo; Arianna Marconi; Caterina La Cascia; Tiago Reis Marques; Carmine Pariante; Paola Dazzan; Valeria Mondelli; Alessandra Paparelli; Anna Kolliakou; Diana Prata; Fiona Gaughran; Anthony S David; Craig Morgan; Daniel Sthal; Mizanur Khondoker; James MacCabe; Robin M Murray

doi:10.1093/schbul/sbt181

Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

Marta Di Forti^*, Hannah Sallis, Fabio Allegri, Antonella Trotta, Laura Ferraro, Simona A Stilo, Arianna Marconi, Caterina La Cascia, Tiago Reis Marques, Carmine Pariante, Paola Dazzan, Valeria Mondelli, Alessandra Paparelli, Anna Kolliakou, Diana Prata, Fiona Gaughran, Anthony S David, Craig Morgan, Daniel Sthal, Mizanur KhondokerJames MacCabe, Robin M Murray

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

362 Citations (Scopus)

1 Downloads (Pure)

Abstract

Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.

Original language	English
Pages (from-to)	1509-1517
Number of pages	9
Journal	Schizophrenia Bulletin
Volume	40
Issue number	6
Early online date	6 Nov 2014
DOIs	https://doi.org/10.1093/schbul/sbt181
Publication status	Published - 17 Dec 2014

Keywords

psychotic disorders
age of onset
gender
cannabis
survival plots
drug use
high-potency cannabis
SUBSTANCE USE
NONAFFECTIVE PSYCHOSIS
SCHIZOPHRENIA
AGE
RISK
GENDER
ASSOCIATION
DELTA-9-TETRAHYDROCANNABINOL
VULNERABILITY
METAANALYSIS

Access to Document

10.1093/schbul/sbt181

362 Citations
1 Article

Is the association between cannabis use and an earlier onset of psychosis an artefact?
Di Forti, M., Sallis, H., Allegri, F., Trotta, A., Ferraro, L., Stilo, S., La Cascia, C., Reis-Marques, T., Pariante, C., Dazzan, P., Mondelli, V., Paparelli, A., Kolliakou, A. A., Gaughran, F. P., Morgan, A. S., Stahl, D. R., MacCabe, J. H. & Murray, R. M., 2014, In: Schizophrenia Bulletin.
Research output: Contribution to journal › Article › peer-review

Cite this

Di Forti, M., Sallis, H., Allegri, F., Trotta, A., Ferraro, L., Stilo, S. A., Marconi, A., La Cascia, C., Reis Marques, T., Pariante, C., Dazzan, P., Mondelli, V., Paparelli, A., Kolliakou, A., Prata, D., Gaughran, F., David, A. S., Morgan, C., Sthal, D., ... Murray, R. M. (2014). Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users. Schizophrenia Bulletin, 40(6), 1509-1517. https://doi.org/10.1093/schbul/sbt181

@article{b5574107813b4666a730572cc58c41c1,

title = "Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users",

abstract = "Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.",

keywords = "psychotic disorders, age of onset, gender, cannabis, survival plots, drug use, high-potency cannabis, SUBSTANCE USE, NONAFFECTIVE PSYCHOSIS, SCHIZOPHRENIA, AGE, RISK, GENDER, ASSOCIATION, DELTA-9-TETRAHYDROCANNABINOL, VULNERABILITY, METAANALYSIS",

author = "{Di Forti}, Marta and Hannah Sallis and Fabio Allegri and Antonella Trotta and Laura Ferraro and Stilo, {Simona A} and Arianna Marconi and {La Cascia}, Caterina and {Reis Marques}, Tiago and Carmine Pariante and Paola Dazzan and Valeria Mondelli and Alessandra Paparelli and Anna Kolliakou and Diana Prata and Fiona Gaughran and David, {Anthony S} and Craig Morgan and Daniel Sthal and Mizanur Khondoker and James MacCabe and Murray, {Robin M}",

year = "2014",

month = dec,

day = "17",

doi = "10.1093/schbul/sbt181",

language = "English",

volume = "40",

pages = "1509--1517",

journal = "Schizophrenia Bulletin",

issn = "0586-7614",

publisher = "Oxford University Press",

number = "6",

}

Di Forti, M , Sallis, H, Allegri, F, Trotta, A, Ferraro, L, Stilo, SA, Marconi, A, La Cascia, C, Reis Marques, T , Pariante, C , Dazzan, P , Mondelli, V , Paparelli, A , Kolliakou, A , Prata, D , Gaughran, F , David, AS , Morgan, C , Sthal, D , Khondoker, M , MacCabe, J & Murray, RM 2014, 'Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users', Schizophrenia Bulletin, vol. 40, no. 6, pp. 1509-1517. https://doi.org/10.1093/schbul/sbt181

TY - JOUR

T1 - Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

AU - Di Forti, Marta

AU - Sallis, Hannah

AU - Allegri, Fabio

AU - Trotta, Antonella

AU - Ferraro, Laura

AU - Stilo, Simona A

AU - Marconi, Arianna

AU - La Cascia, Caterina

AU - Reis Marques, Tiago

AU - Pariante, Carmine

AU - Dazzan, Paola

AU - Mondelli, Valeria

AU - Paparelli, Alessandra

AU - Kolliakou, Anna

AU - Prata, Diana

AU - Gaughran, Fiona

AU - David, Anthony S

AU - Morgan, Craig

AU - Sthal, Daniel

AU - Khondoker, Mizanur

AU - MacCabe, James

AU - Murray, Robin M

PY - 2014/12/17

Y1 - 2014/12/17

N2 - Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.

AB - Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.

KW - psychotic disorders

KW - age of onset

KW - gender

KW - cannabis

KW - survival plots

KW - drug use

KW - high-potency cannabis

KW - SUBSTANCE USE

KW - NONAFFECTIVE PSYCHOSIS

KW - SCHIZOPHRENIA

KW - AGE

KW - RISK

KW - GENDER

KW - ASSOCIATION

KW - DELTA-9-TETRAHYDROCANNABINOL

KW - VULNERABILITY

KW - METAANALYSIS

U2 - 10.1093/schbul/sbt181

DO - 10.1093/schbul/sbt181

M3 - Article

C2 - 24345517

SN - 0586-7614

VL - 40

SP - 1509

EP - 1517

JO - Schizophrenia Bulletin

JF - Schizophrenia Bulletin

IS - 6

ER -

Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

Abstract

Keywords

Access to Document

Fingerprint

Research output

Is the association between cannabis use and an earlier onset of psychosis an artefact?

Cite this