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Published on: August 18, 2020
Heritability of cannabis initiation in Dutch adult twins
Jacqueline M Vink1, Liselot M C Wolters, Michael C Neale
1Dept. Biological Psychology, VU University, 1081 BT Amsterdam, The Netherlands. jm.vink@psy.vu.nl
Abstract:
Previous studies exploring the heritability of cannabis initiation have been carried out in the United States, Australia and United Kingdom. In the present study we assess cannabis initiation in The Netherlands, where the use of cannabis in small amounts is permitted. The sample included 3115 twins with a mean age of 27.4 years (SD 4.7) who are registered with the Netherlands Twin Register (NTR). Individual differences in cannabis initiation showed moderate genetic influences (44%). The remaining variance was explained by environmental influences shared by twins (31%) and by unique environmental factors (24%). Compared to studies from other countries, these results suggest that the relative importance of genetic and environmental factors is not different in a country with a more liberal cannabis policy.
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