Effects on Psychosis

Historical Perception of Cannabis and Mental Health

  • Reefer Madness and the 1930s:

    • The 1930s film Reefer Madness serves as a primary example of historical propaganda regarding cannabis. This film was created to warn people about the dangers of cannabis, but it is seen today as exaggerative and misleading.

    • Movie posters from that era depicted cannabis as a dangerous substance that caused individuals to lose their minds and engage in negative behaviors. The portrayal suggested that using cannabis would lead to a breakdown of a person's mental state, which was not an accurate reflection of reality.

    • The movie was originally sponsored by a religious organization, highlighting how some groups sought to scare the public into avoiding cannabis. This could be seen as part of broader anti-drug initiatives that aimed to control behavior through fear.

    • While these depictions may not have represented the view of the entire general population at the time, they represented the perspective of a specific portion of the population that was concerned about drugs and mental health. Many people began to associate cannabis with insanity and criminality.

    • The perception was characterized by the idea that cannabis was inherently bad for mental stability, though the reality of the connection is far more complex than depicted in media. Research today indicates that many factors contribute to mental health, and cannabis is just one of many substances that can have different effects on different people.

The Theoretical Framework of Cannabis-Induced Psychosis

  • The Complexity of the Relationship:

    • The lecturer describes the relationship between cannabis and psychosis as being "it’s complicated." This means that scientists and researchers have not yet fully understood how cannabis affects mental health and why some users may experience psychosis while others do not.

    • There is no single, clear-cut connection; rather, the relationship varies depending on whether one is discussing acute psychosis (short-term episodes) or long-term, persistent psychosis (where symptoms last for a long time).

  • Four Primary Investigative Questions:

    • 1. Does cannabis use cause psychosis?

    • 2. Does cannabis cause acute psychosis, and does it cause persistent psychosis?

    • 3. Regarding persistent psychosis, does the timing of consumption matter? (e.g., does it matter if the user was an adult or an adolescent when the persistent use occurred?)

    • 4. Can cannabis or related compounds (such as CBD) be utilized to treat psychosis?

Acute Psychosis and the Role of THC

  • Definition and Symptoms of Acute Psychosis:

    • Acute psychosis refers to immediate, short-term symptoms including paranoia (feeling overly suspicious or fearful), hallucinations (seeing or hearing things that aren't there), delusions (strong beliefs in things that aren't true), general "bad feelings," and imagining things that are not grounded in reality. People experiencing acute psychosis may feel completely disconnected from reality, leading to a frightening experience.

  • Direct Induction and Medical Observation:

    • Injecting THC (Tetrahydrocannabinol), the psychoactive component of cannabis, directly into a patient has been shown to induce acute psychotic effects. This finding suggests that THC can influence brain function in a way that mimics psychological breakdown.

    • A significant finding is that typical antipsychotic medications, which generally act as dopamine receptor antagonists, cannot block or reverse the psychotic effects caused by THC injection. This means that the way THC triggers psychosis may be different from the traditional mechanisms behind psychosis that antipsychotics target.

    • As of current research, the exact biological mechanism through which THC triggers these effects remains unclear, showing that more work is needed to disentangle these complex interactions.

  • Individual Susceptibility and Neural Noise:

    • Not all individuals who consume THC or cannabis suffer from psychotic side effects; for many, these effects are absent, while for others, they are very severe. This variation shows that genetics, environment, and individual factors play a significant role in susceptibility to these effects.

    • The COMT Hypothesis: Researchers suspect that a polymorphism in the catechol-O-methyltransferase (COMT) enzyme may determine susceptibility. This drug-metabolizing enzyme might lead to changes in THC metabolism, causing a buildup of specific molecules or the production of different molecules in certain individuals, affecting how THC impacts mental health.

    • Hippocampal Neural Noise: In the brain, THC causes what is termed "neural noise" in the hippocampus. This refers to aberrant action potentials (neurons firing when they should not be firing), which can disrupt normal brain functions.

    • This result mimics what is observed in schizophrenia, a severe mental disorder. While the end result—neural noise—is the same, the routes to that endpoint are likely different between standard schizophrenia and THC-induced psychosis.

Persistent Psychosis and Statistical Correlations

  • Correlation Data:

    • There is a strong correlation between cannabis use and persistent psychosis. Studies suggest that the more cannabis people use, particularly potent strains, the higher their chances of experiencing long-term mental health issues.

    • Occasional cannabis users show a roughly 40\text{\text{%}} increase in the rate of psychosis compared to non-users. This means even infrequent use can have serious repercussions for some individuals.

    • Frequent cannabis users have essentially a "double risk" (an increase of approximately 100\text{\text{%}}) of developing psychosis. Regular, heavy use has been linked to various mental health issues, reinforcing the need for caution.

  • The "Chicken or the Egg" Dilemma:

    • Evidence suggests that cannabis use increases the risk of developing psychosis later in life. Studies indicate that early users may be more likely to face severe mental health issues as adults.

    • However, the reverse is also true: individuals suffering from psychotic episodes are more likely to use cannabis, potentially as a form of self-medication. This complex relationship complicates the understanding of causality and urges further investigation.

  • Genetic Factors and Marker Genes:

    • Whether the COMT polymorphism affects persistent psychosis is currently unclear. More research is needed on how genetics play a role in mental health issues.

    • While some polymorphisms correlate with cannabis use and psychosis, it is possible that these genes are "marker genes" rather than "causative genes."

    • Definition of a Marker Gene: A gene located on a chromosome very near a causative gene. Because chromosomes are inherited in "chunks," an individual who inherits the causative gene is highly likely to inherit the nearby marker gene.

    • This leads to two possibilities: either one polymorphism causes both the cannabis use and the psychosis independently, or researchers have identified markers for a nearby causative gene that has not yet been discovered. This uncertainty complicates the understanding of the relationship between cannabis use and mental health.

Adolescence and Brain Development

  • Adolescent Vulnerability:

    • Several studies indicate that cannabis use during adolescence increases the risk of developing psychosis in adulthood. The adolescent brain is still developing, which means it may be particularly sensitive to substances like THC.

    • The endocannabinoid system plays a critical role in neural development. Introducing exogenous cannabinoids (cannabinoids from outside the body, like THC) to a brain that is not yet fully developed is believed to disrupt the central nervous system's formation.

    • This disruption during critical developmental stages could lead to lasting changes in brain function and behavior.

  • Research Limitations and Animal Models:

    • It is difficult to isolate the effects of adolescent use because people who start early generally consume more total cannabis by adulthood than those who start later. This complicates the research and makes it hard to draw clear conclusions.

    • A "clean" study population of people who used heavily in adolescence but stopped completely in adulthood is difficult to find, making definitive studies challenging.

    • There are currently no good animal models for psychosis. While researchers could give THC to adolescent rats, there is no reliable way to measure or identify psychosis in animals, nor is there a reliable non-cannabis method for inducing and measuring a model of the condition in animals.

    • This gap in research poses challenges for understanding cannabis's effects on psychosis completely.

Cannabidiol (CBD) as a Potential Treatment

  • Strain Variation:

    • Old cannabis strains were characterized by low THC and fairly high CBD levels. This means that early cannabis had different effects compared to modern strains that tend to be very high in THC.

    • Modern strains are typically very high in THC and low in CBD, which may explain why certain strains are more likely to induce psychosis than others. The balance between these compounds is critical for understanding the overall effects of cannabis.

  • CBD as an Antipsychotic:

    • CBD has been shown to reverse the psychotic effects caused by THC in humans. Some studies indicate that CBD can counteract the negative mental effects that THC can cause, leading to ongoing investigations into its therapeutic potential.

    • In clinical contexts, CBD has performed as well as the FDA-approved antipsychotic drug Amisulpride. This suggests that CBD might offer a safer alternative for treating psychosis.

  • Safety and Side Effects:

    • Current FDA-approved antipsychotics like Amisulpride often have severe, debilitating, and life-changing side effects because they affect overall brain function. Such challenges point to the need for alternative treatments.

    • CBD is considered very safe and does not possess the neurological or brain side effects associated with traditional antipsychotic medications. This is a significant advantage, especially for patients who struggle with the side effects of conventional treatments.

    • Research in this field is ongoing, with many questions still unanswered regarding the exact mechanisms of both the cause and the potential treatment. Overall, the developing science around cannabis and mental health continues to challenge our understanding of this complex issue.