International trends in spice use: Prevalence, motivation for use, relationship to other substances, and perception of use and safety for synthetic cannabinoids.

Synthetic cannabinoids (SC), commonly known as Spice, are a class of compounds that share affinity for the cannabinoid receptors. Recreational use of SCs has grown in recent years. A literature search was conducted of national and international organizations as well as peer-reviewed publications describing SC use in non-clinical populations. Our primary goal was summarizing SC use prevalence within the general population from representative surveys. Our secondary goals included describing SC use frequency, motivation for use, the relationship between SC use and use of other substances, and perception of SC use including beliefs about safety and use by peers. Nationally and regionally representative surveys describe lifetime prevalence of SC use in the general population as between 0.2% and 4%. Longitudinal data, though limited, shows decline in SC use with peak use occurring in the late teens and early twenties. Users tend to be males. The majority of SC users report using only a small number of times and use tends to not be sustained. The most common motive for SC use is curiosity. SC users generally report a history of extensive use of other substances. Perception of SC use by others tends to be significantly greater than actual SC use.