Tielbeek JJ, Vink JM, Polderman TJC, Popma A, Posthuma D, Verweij KJH. Drug Alcohol Depend. 2018; 187: 296-299.
Affiliation
Behavioural Science Institute, Radboud University, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands; Department of Biological Psychology/Netherlands Twin Register, VU University, van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands; Department of Psychiatry, Amsterdam Medical Center, University of Amsterdam, Meibergdreef 5, 1105 AZ Amsterdam, The Netherlands. Electronic address: karin.verweij@amc.nl.
BACKGROUND: There is high comorbidity between antisocial behaviour (ASB) and substance use, and twin studies have shown that part of the covariation is due to overlapping genetic influences. Here we used measured genetic effects to estimate the genetic correlations of ASB with nicotine, alcohol, and cannabis use.
METHODS: We meta-analysed data from two genome-wide association studies for ASB and used existing summary statistics from the largest genome-wide association studies into substance use (ever smoking, cigarettes smoked per day, weekly alcohol consumption, and lifetime cannabis use). We performed cross-trait LD-score regression to estimate genetic correlations between ASB and substance use phenotypes explained by all single nucleotide polymorphisms (SNPs). When significant, we tested whether the signs of the regression coefficients of SNPs from the ASB and substance use phenotypes were in the same direction across multiple p-value thresholds and examined enrichment in overlap of the strongest associated SNPs.
RESULTS: We found nominally significant genetic correlations of ASB with lifetime cannabis use (rg = 0.69, p=.016) and cigarettes per day (rg = 0.59, p = 0.036) but not with weekly alcohol consumption or ever smoking. Sign-tests revealed consistent directions of effect of SNPs for ASB and cannabis use for all p-value thresholds except the most stringent one, whereas for ASB with cigarettes per day no consistent evidence was found. We found no evidence of enrichment in overlap of the most associated SNPs across these traits.
CONCLUSION: Using measured genetic variants, we found preliminary support for a genetic correlation of ASB with lifetime cannabis use and cigarettes per day.