In the first prospective study of synthetic cannabinoids or SCs – the group of chemicals that mimic the effects of marijuana – researchers have found that symptoms of depression, drinking alcohol, or using marijuana was linked to an increased risk of SC use one year later.

Synthetic cannabinoids are a large group of chemicals that are similar to THC, the active ingredient in marijuana that produces its hallmark effects. These chemicals may be sprayed on plant–based materials that resemble cannabis and sold as “not for human consumption” potpourri or incense at stores. These chemicals can be as much as 40–600 times more potent than THC.

“The study, recently published in the journal Pediatrics, was the first to assess whether marijuana use is predictive of SC use over time or vice versa,” said senior author Jeff Temple, a clinical psychologist at The University of Texas Medical Branch at Galveston. “Given that marijuana is the most commonly used illicit drug by high school students in the U.S., having a better understanding of how marijuana use affects future SC use and vice versa is essential for designing effective prevention and intervention programs.”

Temple noted that synthetic cannabinoids appeal to adolescents and young adults because of their ease of access, perceived legality, affordable cost, attractive labeling and inability to be detected in urine drug screens.

There were 964 high school students who participated in the study. All students completed surveys that gathered information on SC and marijuana use, alcohol and other drug use, symptoms of anxiety and depression, level of impulsivity and demographic information. They completed the survey again a year later.

With respect to mental health, the researchers found that depressive symptoms, but not anxiety or impulsivity, were predictive of later SC use, suggesting that symptoms of depression may increase the likelihood of use. The same relationship between depressive symptoms and greater propensity for marijuana use was not found.

“The potentially substantial risk associated with using synthetic cannabinoids even once highlights the critical importance of identifying and targeting potential risk factors,” said Temple. “Our findings suggest that prevention and intervention efforts may benefit from targeting depressive symptoms and alcohol and marijuana use to potentially reduce adolescent use of SCs.”