Recommended Conferences

Neuroscience Psychiatry

Dubai, UAE

2nd International Conference on Clinical Psychiatry

Miami, USA

Psychology and Mental Health

Chicago, USA
Related Subjects
 

Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: A case-control study

Author(s): Di Forti M, Marconi A, Carra E, Fraietta S, Trotta A, et al.

Abstract

Background

The risk of individuals having adverse effects from drug use (eg, alcohol) generally depends on the frequency of use and potency of the drug used. We aimed to investigate how frequent use of skunk-like (high-potency) cannabis in south London affected the association between cannabis and psychotic disorders.

Methods

We applied adjusted logistic regression models to data from patients aged 18–65 years presenting to South London and Maudsley NHS Foundation Trust with first-episode psychosis and population controls recruited from the same area of south London (UK) to estimate the effect of the frequency of use, and type of cannabis used on the risk of psychotic disorders. We then calculated the proportion of new cases of psychosis attributable to different types of cannabis use in south London.

Findings

Between May 1, 2005, and May 31, 2011, we obtained data from 410 patients with first-episode psychosis and 370 population controls. The risk of individuals having a psychotic disorder showed a roughly three-times increase in users of skunk-like cannabis compared with those who never used cannabis (adjusted odds ratio [OR] 2·92, 95% CI 1·52–3·45, p=0·001). Use of skunk-like cannabis every day conferred the highest risk of psychotic disorders compared with no use of cannabis (adjusted OR 5·4, 95% CI 2·81–11·31, p=0·002). The population attributable fraction of first-episode psychosis for skunk use for our geographical area was 24% (95% CI 17–31), possibly because of the high prevalence of use of high-potency cannabis (218 [53%] of 410 patients) in our study.

Interpretation

The ready availability of high potency cannabis in south London might have resulted in a greater proportion of first onset psychosis cases being attributed to cannabis use than in previous studies.

Similar Articles

A role for cannabinoid CB1 receptors in mood and anxiety disorders

Author(s): Witkin JM, Tzavara ET, Nomikos GG

Adverse health effects of non-medical cannabis use

Author(s): Hall W, Degenhardt L

Parietal lobe volume deficits in adolescents with schizophrenia and adolescents with cannabis use disorders

Author(s): Kumra S, Robinson P, Tambyraja R, Jensen D, Schimunek C, et al.

Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users

Author(s): Di Forti M, Sallis H, Allegri F, Trotta A, Ferraro L, et al.

Prevalence and intensity of basic symptoms among cannabis users: An observational study

Author(s): Martinotti G, Di Iorio G, Tedeschi D, De Berardis D, Niolu C, et al.

Rates of psychiatric comorbidity among U

Author(s): Agosti V, Nunes E, Levin F

Cannabis use and depression: a longitudinal study of a national cohort of Swedish conscripts

Author(s): Manrique-Garcia E, Zammit S, Dalman C, Hemmingsson T, Allebeck P

Escalation of drug use in early-onset cannabis users vs

Author(s): Lynskey MT, Heath AC, Bucholz KK, Slutske WS, Madden PA, et al.

A co twin-control analysis of drug use and abuse/dependence risk associated with early-onset cannabis use

Author(s): Grant JD, Lynskey MT, Scherrer JF, Agrawal A, Heath AC, et al.

Cannabis use and risk of psychotic or affective mental health outcomes: A systematic review

Author(s): Moore THN, Zammit S, Lingford-Hughes A, Barnes TRE, Jones PB

Genetic predisposition to schizophrenia associated with increased use of cannabis

Author(s): Power RA, Verweij KJH, Zuhair M, Montgomery GW, Henders AK, et al.

The association between cannabis use and depression: A systematic review and meta-analysis of longitudinal studies

Author(s): Lev-Ran S, Roerecke M, Le Foll B, George TP, McKenzie K, et al.

Major depression: The relative contribution of gender, MDMA and cannabis use

Author(s): Durdle H, Lundahl LH, Johanson CE, Tancer M

Relief-oriented use of marijuana by teens

Author(s): Bottorff JL1, Johnson JL, Moffat BM, Mulvogue T

Motives for drug use among light and heavy users

Author(s): Nail RL, Gunderson EK, Kolb D

Risk factors predicting changes in marijuana involvement in teenagers

Author(s): Van den Bree, Marianne BM, Wallace BP

Affect dysregulation in cannabis abusers: A study in adolescents and young adults

Author(s): Dorard G, Berthoz S, Phan O, Corcos M, Bungener C

Adolescent depression and risk factors

Author(s): Field T, Diego M, Sanders C

Cannabis, motivation and life satisfaction in an internet sample

Author(s): Barnwell SS, Earleywine M, Wilcox R

Sequencing of substance use and affective morbidity in 166 first episode bipolar I disorder patients

Author(s): Baethge C, Hennen J, Khalsa HM, Salvatore P, Tohen M, et al.

Adverse health effects of marijuana use

Author(s): Volkow ND, Baler RD, Compton WM, Weiss SR