What Is the Relationship Between Cannabis Use and Psychosis?


The Relationship Between Cannabis Use and Psychosis

Whether cannabis can cause debilitating mental disorders like schizophrenia is still unknown. Yet, there is plenty of evidence that suggests an overlap between cannabis use and schizophrenia and psychosis. In addition, it is evident that cannabis users, especially adolescents, are at greater risk for psychosis and at an earlier age.

Some evidence suggests that cannabis can cause psychosis in people where it otherwise would not occur.  However, most research indicates a positive correlation between the two, as cannabis use in those who have psychosis exceeds the general population’s by 40%. Thus, while we cannot conclude that cannabis use causes schizophrenia or vice versa,  they are irrefutably related, and some serious risks are involved.

Other risks of cannabis use in those with psychosis:

  • Less responsive to treatment
  • More severe course of illness
  • Decreased medication compliance
  • More suicide attempts

Evidence that cannabis use directly causes long-term brain change is less prolific. Still, some studies show a connection between schizophrenic brains and the effects that cannabis has on the brain. In the brain, cannabinoid receptors are present in the hippocampus, amygdala, cerebellum, basal ganglia, and cerebral cortex. In Schizophrenic patients, reactivity in these receptors and their density in the brain is different than in the general population, suggesting at least a vulnerability to the harmful effects of cannabis.

The long-term effects of cannabis use are not well established.  The question exists, can short-term effects be a predictor of long-term issues? The short-term effects of cannabis are well-known. In a study on the effects of THC on healthy individuals without a cannabis use disorder, intravenous doses caused schizophrenic symptoms and significant memory impairment. Some research hypothesizes that this symptom onset could be due to increased dopamine output caused by cannabis use which mimics schizophrenic symptoms.

Researchers cannot yet draw definitive conclusions about the long-term effects of cannabis on the brain. Still, the dangers of cannabis use and psychosis onset should be enough to encourage caution.

 How Cannabis Affects Your Mood

Media often downplays how cannabis affects a person’s mood, suggesting that it makes them more agreeable with few other consequences. Intermittent use of cannabis has not been shown to affect mood negatively.  However, daily and almost daily use has a modest relationship, according to the Society for the Study of Addiction 2003 article titled “Exploring the Association Between Cannabis Use and Depression.” As previously discussed, cannabis use can put you at risk for schizophrenic symptoms and psychosis, and while this may resolve quickly, it can turn into early or late-onset psychosis.

According to a 2007 article published in Drug and Alcohol Dependence titled “Cannabis Use and Cannabis Use Disorders and Their Relationships to Mental Disorders: A Ten-Year Prospective-Longitudinal Community Study in Adolescents,” many turn to cannabis to self-medicate mood disorders.  Culture has perpetuated the idea that cannabis is an appropriate stand-alone treatment because it’s “not addictive.'” Studies have repeatedly shown that decreasing cannabis use improves depression symptoms, as found in the 2017 study published in the Journal of Substance Abuse Treatment called “Reductions in Cannabis Use Are Associated With Improvements of Anxiety, Depression, and Sleep Quality, But Not Quality of Life.”   A study called “Discontinuing Cannabis Improves Depression in People With Multiple Sclerosis: A Short Report” published in the Multiple Sclerosis Journal in 2020 found discontinuing cannabis caused a significant improvement in depression symptoms. Cannabis withdrawal can cause irritability, restlessness, anxiety, and depression, making relapse likely, as noted in a 2008 article published in Addictive Behaviors titled “Cannabis Withdrawal Is Common Among Treatment-Seeking Adolescents With Cannabis Dependence and Major Depression, and Is Associated With Rapid Relapse to Dependence.”

Cannabis in moderation can be a helpful supplemental treatment in conjunction with therapy for mood disorders and trauma.  However, minimizing cannabis to a harmless and risk-free option is dangerous to those vulnerable to psychosis and depression, as reported in a 2017 article published in the Journal of Clinical Medicine titled “Impact of Cannabis Use on Treatment Outcomes Among Adults Receiving Cognitive-Behavioral Treatment for PTSD and Substance Use Disorders.”

Signs That Cannabis Is Causing or Worsening Psychosis in You or Someone You Know

Cannabis can cause short-term psychosis symptoms in anyone. Still, you may need treatment if psychosis symptoms worsen or occur outside of cannabis use.

“What Is Early and First-Episode Psychosis,” a 2016 National Alliance on Mental Illness article, reports the following warning signs:

  • Having sensory experiences or believing things that others don’t
  • Being uneasy or suspicious around others
  • Unusual thoughts or beliefs that are persistent in day-to-day life
  • Lack of emotion or strong and inappropriate emotions
  • Social or familial withdrawal and isolation
  • Suddenly not practicing self-care or hygiene
  • Trouble concentrating or thinking clearly
  • A drop in performance at work or school
  • Difficulty telling what’s real
  • Nonsensical or confused speech or issues communicating

Someone experiencing psychosis should not use cannabis, as it can worsen symptoms and make treatment more difficult. In addition, it can be hard to quit when dependence occurs, and time is of the essence to prevent danger to yourself or others.

Cannabis use and psychosis are inextricably linked, and the dangers of cannabis use for those vulnerable to schizophrenia should not be understated. Finding treatment for psychotic symptoms is critical to recovery, and if cannabis use is a factor in symptom severity, Casa Recovery can help you overcome your addiction. Of course, there are many reasons that substance abuse and mental health conditions co-occur. Still, dual diagnosis treatment that focuses on the addiction and the disorder has been proven more effective than standalone treatment options. At Casa Recovery, dual diagnosis treatments are used to create long-term change. Through working with our team of trained and licensed mental health professionals, you can take charge of your recovery, learn about your condition, and create connections that will help carry you through life long after you leave our care. Call or text Casa Recovery today at (888) 928-2272 to discuss treatment options for your dual diagnosis.

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