PROJECT SUMMARY
High-potency cannabis use is associated with public health risks, such as cannabis use disorder, psychotic
disorders, and impaired cognition. Legal markets in the US and Canada are geared towards the
commercialization of high-tetrahydrocannabinol (THC) products, including concentrates as high as 90-95%. The
cannabis industry has resisted regulation of higher-potency products claiming that cannabis consumers naturally
self-titrate their use, but the limited evidence to date suggests that even though consumers may use less
cannabis as potency rises, consuming higher potency products still leads to greater THC consumption.
We will use a randomized crossover trial to evaluate the ability of 36 regular cannabis consumers (18 females
and 18 males) to self-titrate the THC dose when vaping concentrates to achieve the desired psychoactive effects.
We will also characterize and compare the subjective, cognitive, physiological, and pharmacokinetic effects
between cannabis concentrates of different potencies (30%, 60%, and 90% THC). Working with US scientists,
the setting of this study will be Toronto, Canada, in the context of federal legalization of cannabis, unique access
to cannabis products not available in the US for research purposes, and an encouraging regulatory environment.
We will test commercial products that are representative of the THC ranges available in the legal market.
Aim 1: To evaluate the ability of regular cannabis consumers to self-titrate their THC dose when vaping
concentrates of different potencies. We will compare markers of titration (biological: THC blood levels;
behavioral: inhalation topography; subjective: self-reported levels of intoxication) over a range of potencies for a
comprehensive characterization of titration practice. We hypothesize that participants will be able to partially but
not proportionally reduce THC intake with increase in THC potency. In other words, we anticipate that the
proportional decrease in blood THC levels will be lower than the proportional increase in THC concentrations.
Aim 2: To compare the cognitive impairment, physiological effects, and addiction liability of consuming lower
versus higher THC potency concentrates. We hypothesize that cognitive impairment and physiological effects
will be less pronounced with lower-THC concentrates in a dose-response fashion. We will also explore
differences in addiction liability between potencies as higher THC concentrations may result in greater dysphoric
reactions. These acute effects may be related to long term harms such as accidents, CVD events, and CUD.
Exploratory Aim: To explore sex differences in titration efficiency, blood THC concentrations, cognitive
impairment, physiological effects, and addiction liability. We propose to analyze sex differences in our primary
and secondary outcomes (e.g., whether females will be able to titrate more efficiently than males).
This experimental evidence will provide data on the potential acute harms related to concentrates and inform
policy decisions on the need to decrease access and/or prevent their initiation and implement information and
education campaigns to increase awareness on the risks of using them.