Overlap of heritable influences between cannabis use disorder, frequency of use and opportunity to use cannabis: trivariate twin modelling and implications for genetic design

Lindsey A Hines, Katherine I Morley, Fruhling V. Rijsdijk, John Strang, Arpana Agrawal, Elliot C. Nelson, Dixie Statham, Nicholas G Martin, Michael T. Lynskey

Research output: Contribution to journalArticle (Academic Journal)peer-review

265 Downloads (Pure)

Abstract

BACKGROUND:
The genetic component of Cannabis Use Disorder may overlap with influences acting more generally on early stages of cannabis use. This paper aims to determine the extent to which genetic influences on the development of cannabis abuse/dependence are correlated with those acting on the opportunity to use cannabis and frequency of use.

METHODS:
A cross-sectional study of 3303 Australian twins, measuring age of onset of cannabis use opportunity, lifetime frequency of cannabis use, and lifetime DSM-IV cannabis abuse/dependence. A trivariate Cholesky decomposition estimated additive genetic (A), shared environment (C) and unique environment (E) contributions to the opportunity to use cannabis, the frequency of cannabis use, cannabis abuse/dependence, and the extent of overlap between genetic and environmental factors associated with each phenotype.

RESULTS:
Variance components estimates were A = 0.64 [95% confidence interval (CI) 0.58-0.70] and E = 0.36 (95% CI 0.29-0.42) for age of opportunity to use cannabis, A = 0.74 (95% CI 0.66-0.80) and E = 0.26 (95% CI 0.20-0.34) for cannabis use frequency, and A = 0.78 (95% CI 0.65-0.88) and E = 0.22 (95% CI 0.12-0.35) for cannabis abuse/dependence. Opportunity shares 45% of genetic influences with the frequency of use, and only 17% of additive genetic influences are unique to abuse/dependence from those acting on opportunity and frequency.

CONCLUSIONS:
There are significant genetic contributions to lifetime cannabis abuse/dependence, but a large proportion of this overlaps with influences acting on opportunity and frequency of use. Individuals without drug use opportunity are uninformative, and studies of drug use disorders must incorporate individual exposure to accurately identify aetiology.
Original languageEnglish
Pages (from-to)2786-2793
Number of pages8
JournalPsychological Medicine
Volume48
Issue number16
Early online date13 Mar 2018
DOIs
Publication statusPublished - Dec 2018

Fingerprint Dive into the research topics of 'Overlap of heritable influences between cannabis use disorder, frequency of use and opportunity to use cannabis: trivariate twin modelling and implications for genetic design'. Together they form a unique fingerprint.

Cite this