As marijuana has gained popularity and generalized acceptance across the globe, high potency marijuana has emerged as an increasingly available option that has contributed to intensification of marijuana use.
Marijuana is composed of a combination of compounds that are collectively referred to as cannabinoids: cannabidiol, or CBD, and tetrahydro-cannabidiol, or THC. THC is the primary psychoactive component of marijuana, whereas CBD is thought to be responsible for the many physical symptoms you might experience when you use. When we talk about potency, we’re referring to the ratio of THC to CBD. This ratio is primarily what dictates the psychoactive strength of the strain of marijuana you’re consuming, with higher THC:CBD ratios corresponding to more mind-altering effects.
Over the past 40 years, marijuana potency has approximately doubled worldwide (Cascini, Curr Drug Abuse Rev, 2012; WHO, Cannabis, 2016). In the United States, chemical analysis of marijuana potency from samples confiscated by the Drug Enforcement Administration have shown that the average concentration of THC increased from about 4% in 1995 to 17% in 2017 (ElSohly, Biol Psychiatry, 2016; Chandra, Eur Arch Psychiatry Clin Neurosci, 2019). Meanwhile, the CBD content of marijuana strains has actually decreased, from an average of 0.28% in 2001 to less than 0.15% in 2014. The end result is that marijuana’s average THC:CBD ratio has increased from approximately 14 to 80 from 1995 to 2014 alone (ElSohly, Biol Psychiatry, 2016). So, while research has shown that CBD can actually offset some of THC’s more harmful effects, like memory impairment and psychotic-like symptoms, shifts in marijuana’s chemical makeup mean that the marijuana you may consume today is much more likely to cause unpleasant side effects (Englund, J Psychopharmacol, 2013).
A growing body of research implicates high potency marijuana as being associated with negative health outcomes, including increased symptoms of cannabis use disorder (Freeman, Psychol Med, 2015), increased admission for specialist drug treatment (Freeman, Psychol Med, 2018), and higher risk of developing psychosis (Di Forti, Lancet Psychiatry, 2015). Needless to say, increased potency of available marijuana strains has important implications for your health. If you decide to use, pay special attention to the potency of the strain, so that you are aware of likelihood of adverse effects.