After reviewing a local social media post about marijuana and cannabis psychosis, I noticed a substantial amount of misinformation being shared. To help clarify the current evidence, I decided to highlight findings from a recent cohort study examining the rise in adolescent mental health conditions following the legalization of marijuana.
Young‑Wolff et al. (2026) conducted a large-scale cohort study of 463,396 adolescents aged 13 to 17 years who were universally screened for past-year cannabis use at Kaiser Permanente Northern California between 2016 and 2023. Participants were followed through age 25 years or until December 31, 2023, with data analyzed from February 21, 2024, to August 27, 2025. The researchers found that past-year cannabis use was associated with a significantly increased risk of developing incident psychotic, bipolar, depressive, and anxiety disorders by age 26.
This is supported by findings from Starzer et al. (2018), who examined every individual in Denmark diagnosed with substance-induced psychosis and tracked how many later developed schizophrenia. Their results showed that 47% of individuals with cannabis-induced psychosis went on to develop schizophrenia or bipolar disorder, and over 40% developed schizophrenia alone. In other words, experiencing cannabis psychosis confers approximately a 50% likelihood of later developing schizophrenia. When compared with other substances, including methamphetamine, cocaine, and LSD, cannabis was associated with the highest conversion rate to chronic psychotic disorders.
As someone who specializes in the treatment of cannabis-induced psychosis and other psychotic conditions, it is important for the public to understand that these experiences can occur after a single use or after repeated use, including gummies. Many are also surprised to learn that cannabis is uniquely harmful among psychoactive substances in its potential to cause brain changes resembling schizophrenia and bipolar disorder.
Unfortunately, many clinicians in the mental health field are not adequately trained to assess or treat psychosis, including cannabis-induced psychosis, which often leads to misdiagnosis and inappropriate treatment. To date, I have successfully treated several individuals who are now symptom-free, despite initially being misdiagnosed, mismedicated, and not provided with appropriate therapeutic modalities. In each case, a thorough intake and history revealed that symptoms began immediately following cannabis use, often in the context of additional traumatic events.
There are several effective treatment approaches for cannabis-induced psychosis. One of the most widely used and evidence-supported methods is Dr. Paul Miller’s EMDR protocol for schizophrenia and other psychotic disorders, combined with parent and family counseling. When applied correctly, these interventions can significantly reduce symptoms and support long‑term recovery, allowing individuals to live both medication‑free and drug‑free.
My goal in sharing this information is to support clinicians, families, and community members in recognizing cannabis‑related risks and ensuring individuals receive appropriate, evidence‑based care.
Dotti Howe
Hamden
