If you are a heavy user who has recently stopped using marijuana, you may be wondering why you feel so terrible, or feel tempted to use again in order to alleviate your symptoms. Understanding the neurochemistry that underlies withdrawal—while it won’t directly address your symptoms—can at least provide insight into why you’re feeling this way. More importantly, it argues for why returning to cannabis would only set you back at a biologic level.
Marijuana’s primary psychoactive components, THC, effects multiple systems in the body, but has most of its effects in the brain and nervous system, where it binds to signaling proteins on the cell surface called cannabinoid receptors (CB1 and CB2). CB1 is primarily expressed in the brain, while CB2 is found on peripheral nerves, and immune cells. Your body naturally produces a number of molecules that bind and signal through these receptors and are collectively referred to as the endogenous cannabinoid system. While much of the science remains to be investigated, the endogenous cannabinoid system is thought to function in the maintenance of sleep, appetite and memory, amongst other important cognitive functions.
THC, the primary component of marijuana, is similar in structure to the body’s natural or endogenous cannabinoids. When you smoke, THC binding to the cannabinoid receptors stimulates a complex series of changes that creates the experience of being high. Smoking consistently means constant THC-induced stimulation of CB receptors. Over time, your body’s natural protective mechanism is to decrease or downregulate the number of CB receptors on cells. This process is known as desensitization. When you quit, the THC that was once constantly present is suddenly removed, leaving only your endogenous cannabinoids to signal through a diminished number of CB receptors. Withdrawal symptoms are the direct result of dampened ECS activity in the body, which manifests as dysregulations in sleep, mood, appetite, and other bodily functions. The combination of these symptoms creates the cannabis withdrawal syndrome.
Rest assured, though, these changes are not permanent. In fact, withdrawal symptoms signify that your brain is re-equilibrating back to baseline. Although it may be tempting to smoke to alleviate these symptoms in the short-term, it would ultimately be a setback to all the progress both you and your brain have made so far, so stay strong.