Over the eight years he spent smoking “nearly all day,” Greg Papania, a 35-year-old music producer in LA, would access “fascinating thoughts that were beyond this world.” Then, as his life became more stressful, weed began to make him paranoid and even gave him panic attacks.
Similarly, weed used to serve as a creativity enhancer and sleep aid for Allison Moon, a 36-year-old writer in Oregon. “Nowadays, weed is more likely to tip me into a high-anxiety mode,” she says. “I can feel my heartbeat in that ‘pre-anxiety attack’ way.”
On the flip side, Valeria Costa-Kostritsky, a 36-year-old journalist in London, used to get “super paranoid” when she smoked as a teenager. Now, she just gets “a bit silly or shy.”
Cannabis affects different people differently, but it also can affect the same people differently at different points in their lives. It’s not very common but also not unusual for your high to change over time, says James Giordano, professor of neurology and biochemistry at Georgetown University Medical Center.
THC, the substance in cannabis that’s responsible for its anxiety-inducing effects as well as its euphoric ones, activates your CB1 cannabinoid receptors, Giordano explains. After repeated exposure to THC, your CB1 receptors can change their affinity for THC. If this happens, weed may make you more anxious over time. Some people experience the opposite, though, and their CB1 receptors may become desensitized, leading them to feel less anxious and more relaxed. Repeated exposure to THC can also change your chemical reactions downstream from the CB1 receptors in unpredictable ways that may make you either more nervous or more calm. In contrast to THC, cannabidiol (CBD) partially blocks CB1 receptors, which can produce a calming, anti-anxiety effect, Giordano adds.
“Tolerance, habituation to certain drug effects, and sensitization, amplification of certain drug effects, are principles at play across many different drugs,” says Matthew Johnson, professor of psychiatry and behavioral sciences at Johns Hopkins University. “There can be brain receptor up regulation or down regulation, there can be alterations in metabolic pathways, and there can be behavioral tolerance, where one becomes skilled at behaving under the influence of the drug.”
But if it seems like your reaction to weed has changed, it could also just be that you’re smoking a different strain (or “breed”) than you used to, Giordano adds. The ratio of THC to cannabidiol (CBD) has a particularly significant impact on your high.
“THC is what we usually associate with the ‘high’ feeling,” explains Sal Raichbach, an addiction psychiatrist at a Ambrosia Treatment Center location in Florida. “That includes euphoria, increased appetite, and introspection. On the other hand, cannabinol or CBD has almost the opposite effect, giving people a relaxed and calm feeling. Different strains of marijuana have different concentrations and ratios of these chemicals, so the effects vary widely.”
Strains that have a CBD:THC ratio of 1:1 or greater (like indicas and high-CBD hybrids) tend to produce more calming, anti-anxiety effects, Giordano says. But some sativas (like Jack Herer), while generally high in THC, can also be more calming.