An anonymous online survey was conducted in 2011 using a quantitative structured research tool. Missing data (median 2 % ) were treated by available-case analysis.
Of 14,966 participants, 2513 (17 % ) reported use of synthetic cannabis. Of these, 980 (41 % of 2417) reported its use in the last 12 months. Almost all recent synthetic cannabis users (99 % of 975) reported ever use of natural cannabis. Synthetic cannabis reportedly had both a shorter duration of action (z = 17.82, p < .001) and quicker time to peak onset of effect (z = ?9.44, p < .001) than natural cannabis. Natural cannabis was preferred to synthetic cannabis by 93 % of users, with natural cannabis rated as having greater pleasurable effects when high (t(930) = ?37.1, p < .001, d = ?1.22) and being more able to function after use (t(884) = ?13.3, p < .001, d = ?0.45). Synthetic cannabis was associated with more negative effects (t(859) = 18.7, p < .001, d = 0.64), hangover effects (t(854) = 6.45, p < .001, d = 0.22) and greater paranoia (t(889) = 7.91, p < .001, d = 0.27).
Users report a strong preference for natural over synthetic cannabis. The latter has a less desirable effect profile. Further research is required to determine longer term consequences of use and comparative dependence potential.