The association between physical pain and cannabis use in daily life: An experience sampling method.

Background: Previous research shows that between individuals there is a positive association between medically motivated use and cannabis use frequency and quantity. While between-subjects' analyses are useful for understanding shared vulnerabilities, research has so far not examined within-subjects' relationships which are closer to evaluating functional relationships (i.e., do individuals tend to use cannabis more heavily subsequent to elevations in pain experiences?). To better understand the association between experiences of pain and cannabis use, the current paper examines whether there is a functional within-subjects association between experiences of pain and heavy cannabis use.

Methods: 182 regular cannabis users without a medical cannabis license were asked to report momentary experiences of physical pain, whether they had used cannabis, and if so, quantity consumed five times per day over a five-day period on their smartphones. Mixed effects models examined the relations between within- and between-subjects experiences of pain and cannabis use and quantity consumed.

Results: Elevated experiences of pain were not associated with cannabis use occasions at the within- or between-subjects level. Experiences of pain were associated with greater amount of cannabis consumed at the within-subjects level, but not at the between-subjects level.

Conclusions: Experiences of pain are not associated with decisions about whether or not to use cannabis. Once cannabis users are in cannabis-using situations, they tend to use larger amounts when they are experiencing elevated levels of pain. This may have implications for cannabis abuse treatment as pain may make it more difficult for users to reduce their consumption.