Why we think it’s important: 

This article is crucial as it sheds light on the increasingly common yet often overlooked risk of cannabis-induced psychosis, exemplified by the alarming case of Bryn Spejcher. By presenting scientific evidence and real-life incidents, it underscores the need for informed discussions and heightened awareness about the potential mental health consequences associated with marijuana use, particularly in the context of the evolving landscape of cannabis legalization. 


In recent years, the debate surrounding the legalization and recreational use of marijuana has gained momentum. However, an alarming issue has emerged from the shadows, shedding light on the potential risks associated with cannabis consumption. The case of Bryn Spejcher, a 33-year-old who stabbed her partner over 100 times during a cannabis-induced psychotic episode, has brought attention to a rare yet increasingly common side effect of marijuana use – cannabis-induced psychosis. 

Understanding Cannabis-Induced Psychosis: 

Cannabis-induced psychosis is a phenomenon where individuals experience psychosis shortly after using marijuana. Psychosis, as defined in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), encompasses symptoms that challenge the ability to differentiate between reality and fantasy, resulting in a significant detachment from the actual world. The DSM-5 serves as a comprehensive guide utilized by healthcare professionals for diagnosing various mental disorders, providing standardized criteria to understand and categorize psychiatric conditions. While psychosis is often associated with conditions like schizophrenia and bipolar disorder, it can also be triggered by various factors, including sleep deprivation, prescription medications, and the use of substances like cocaine, ecstasy, LSD, amphetamines, and cannabis. 

The Bryn Spejcher Case: 

Spejcher’s case, where she stabbed her partner Chad O’Melia 108 times during a cannabis-induced psychotic episode, is a chilling example of the potential dangers associated with marijuana use. The incident unfolded when Spejcher, a novice marijuana user, experienced hallucinations and believed she needed to kill O’Melia to save herself. Blood tests revealed the presence of THC, the psychoactive compound in cannabis, as the sole intoxicating substance in her system. The prosecution’s medical expert acknowledged the evidence of cannabis-induced psychosis, leading to a reduction of Spejcher’s murder charge to involuntary manslaughter. 

Scientific Support for Concerns: 

Scientific studies underline the growing concerns surrounding cannabis-induced psychosis. A 2019 study published in The Lancet Psychiatry found that daily cannabis users had 3.2 times higher odds of psychosis compared to non-users. For those using high-potency cannabis daily, the risk increased nearly fivefold. The age at which individuals start using cannabis also plays a role, with earlier initiation linked to a higher risk of developing psychosis. 

Changing Landscape of Marijuana: 

One factor contributing to the rise in cannabis-induced psychosis cases is the changing landscape of marijuana. In the early ’90s, the average THC content in confiscated marijuana samples was less than 4%. Today, it can exceed 15%, posing higher risks even with smaller amounts of the drug. As marijuana legalization spreads across states, an increasingly competitive market prompts sellers to produce more potent products. 

Long-Term Consequences and Risk Factors: 

Cannabis-induced psychosis isn’t a one-time occurrence. Individuals experiencing drug-induced psychosis, particularly with potent cannabis, face an increased risk of developing chronic and severe mental illnesses, such as schizophrenia and bipolar disorder. Moreover, a family history of psychosis is identified as a significant risk factor for cannabis-induced psychosis. 


As marijuana becomes more accessible and accepted, it is crucial to acknowledge the potential risks associated with its use, particularly in terms of cannabis-induced psychosis. The case of Bryn Spejcher serves as a stark reminder that while such extreme outcomes are rare, the risks are real and can have severe consequences. The scientific evidence presented underscores the importance of informed discussions and awareness regarding the potential mental health implications of marijuana use. As we navigate the evolving landscape of cannabis legislation, let us not forget the shadows that lurk behind the euphoria, urging us to approach this discussion with both caution and compassion.