Many individuals turn to cannabis products, often called weed, seeking relaxation or a calming effect. For some, this holds true for occasional use. However, as Dr. Kalarco explains in the video above, consistent and chronic cannabis use can sometimes lead to unexpected and even counterintuitive outcomes, such as increased anxiety. This shift in effect, particularly after years of regular consumption, often leaves users puzzled and seeking a scientific explanation.
Understanding why weed can cause anxiety, even when tolerance has developed, involves delving into the brain’s complex endocannabinoid system. This intricate network plays a crucial role in regulating mood, stress response, memory, and appetite. When this system is consistently modulated by external cannabinoids like THC (tetrahydrocannabinol), the primary psychoactive component in cannabis, its natural balance can be disrupted.
The Science Behind Cannabis-Induced Anxiety: Receptor Dysregulation
The core reason chronic cannabis use can cause anxiety, despite initial feelings of relaxation or developing a tolerance, lies in what scientists term “dysregulation of the cannabinoid receptors.” Our brains contain cannabinoid receptors, primarily CB1 and CB2 receptors, which bind with cannabinoids. THC primarily interacts with CB1 receptors in the brain, influencing neurotransmitter release and neuronal activity.
When cannabis is used frequently and over extended periods, these CB1 receptors can become desensitized or downregulated. This means their number on cell surfaces might decrease, or their ability to signal effectively diminishes. Think of it like a lock and key mechanism: with chronic exposure, the locks become less responsive to the keys, requiring more keys (more cannabis) for the same effect, or sometimes, the system just stops responding as intended altogether.
This dysregulation leads to a paradoxical effect. Instead of promoting calm, the altered endocannabinoid system can begin to contribute to heightened anxiety. Research indicates that chronic THC exposure can impair the prefrontal cortex’s ability to regulate the amygdala, a brain region central to fear and anxiety processing. A 2017 study published in the journal Addiction Biology observed structural changes in the brains of chronic cannabis users, suggesting altered fear processing and increased susceptibility to anxiety.
Tolerance Versus Dysregulation: A Key Distinction
Many long-term cannabis users develop a tolerance, meaning they need higher doses to achieve the desired effect. This is a common phenomenon in pharmacology where the body adapts to a substance. However, dysregulation goes beyond simple tolerance.
While tolerance means you need more to feel good, dysregulation implies that the entire system is off-kilter, potentially leading to negative effects even at previously tolerated doses. It’s not just about the intensity of the “high” decreasing; it’s about the entire mood regulation system being compromised. This can manifest as persistent feelings of unease, heightened stress responses, or panic attacks that seem to come out of nowhere.
Factors Influencing Cannabis Effects on Anxiety
Dr. Kalarco briefly mentions that personal genetics, the type of cannabis used, and the frequency and amount of use all play significant roles. Expanding on these points reveals a more nuanced picture of how cannabis interacts with individual physiology.
Genetics and Individual Predisposition
Our genetic makeup dictates how our bodies process various substances, including cannabinoids. Variations in genes encoding cannabinoid receptors, enzymes that metabolize cannabinoids (like CYP2C9 or CYP2C19), or even genes related to stress response can influence an individual’s susceptibility to cannabis-induced anxiety. For instance, specific genetic polymorphisms may lead some individuals to have a more sensitive endocannabinoid system, making them more prone to adverse reactions like anxiety or paranoia, even with moderate use.
A 2013 review in Molecular Psychiatry highlighted how genetic factors can modulate the risk of psychosis and anxiety disorders in cannabis users. This means that what might be a relaxing experience for one person could be anxiety-provoking for another, largely due to their unique genetic blueprint.
The Role of Cannabis Strain and Cannabinoid Profile
Not all cannabis is created equal. The type of cannabis, specifically its cannabinoid and terpene profile, significantly impacts its effects. Modern cannabis strains are often bred for high THC content, which can be a double-edged sword for anxiety.
- THC (Tetrahydrocannabinol): While low doses of THC can be anxiolytic (anxiety-reducing) for some, higher doses, especially in individuals with a sensitive system or chronic users, are strongly associated with increased anxiety and paranoia. THC’s interaction with the amygdala is a primary driver of this effect.
- CBD (Cannabidiol): In contrast, CBD is generally considered anxiolytic and does not produce the “high” associated with THC. It can even mitigate some of THC’s anxiety-inducing effects by modulating CB1 receptor activity. Strains with a higher CBD-to-THC ratio are often recommended for those seeking therapeutic benefits without intense psychoactive effects.
- Terpenes: These aromatic compounds also found in cannabis contribute to its smell and flavor, but also its effects. Terpenes like limonene (found in citrus) and linalool (found in lavender) are thought to have mood-enhancing and relaxing properties. The entourage effect, where cannabinoids and terpenes work synergistically, suggests that a complex plant profile can produce different results than isolated compounds.
Frequency and Amount of Use
As Dr. Kalarco states, “how often and how much you partake” is crucial. While occasional use might bring relaxation, daily or heavy weekly use dramatically increases the likelihood of receptor dysregulation. Studies show that individuals who use cannabis daily have a significantly higher risk of developing cannabis use disorder and experiencing mental health issues like anxiety and depression.
One meta-analysis published in The Lancet Psychiatry in 2019 found that daily use of high-potency cannabis significantly increased the risk of developing a psychotic disorder. While anxiety is distinct from psychosis, the underlying mechanisms of neurological disruption can overlap. The dose-response relationship is clear: higher frequency and potency correlate with greater potential for adverse mental health outcomes.
Navigating the Shift: What to Consider
For individuals who have used cannabis for years and suddenly experience anxiety, understanding these physiological changes is the first step. It’s not necessarily that your body has suddenly “changed” in a mystical way, but rather that chronic exposure has altered the delicate balance of your endocannabinoid system. This realization empowers individuals to make informed choices about their continued cannabis use.
If you’re experiencing increased anxiety or other adverse mental health effects from cannabis, several considerations are important. These include evaluating your current usage patterns, exploring strains with different THC:CBD ratios, or considering a period of abstinence to allow your endocannabinoid system to re-regulate. Consulting with a healthcare professional can also provide personalized guidance, especially when dealing with long-term cannabis use and its potential impact on mental well-being and anxiety management.
