# Cannabis use patterns in first episode psychosis and schizophrenia: A scoping review and case series. > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/cannabis-use-patterns-in-first-episode-psychosis-and-schizophrenia-a-scopin/ > **Published:** 2026-04-28T20:05:33-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T16:04:46-04:00 > **Clinical Summary:** Cannabis use is associated with psychosis development and symptom relapse in persons with schizophrenia spectrum disorders (SCZ). As U.S. states legalize can... --- CED Clinical Relevance  #56Monitored Relevance  Early-stage or contextual signal requiring further evidence before action. 🔬 Evidence Watch  |  CED Clinic Journal Journal of psychiatric research Study Type [Clinical Study](https://cedclinic.com/cannabis-hyperemesis-syndrome-psychiatric-risk/) Population Human participants Why This Matters This item covers developments relevant to [cannabis medicine](https://cedclinic.com/essential-oils-industrial-hemp-antimicrobial-benefits/) and [clinical practice](https://cedclinic.com/cannabis-reproductive-health-women-clinical-evidence/). Clinicians monitoring evidence in this area should review the source material. [Clinical Summary](https://cedclinic.com/recreational-marijuana-legalization-24-states-update/) [Cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) is associated with psychosis development and symptom relapse in persons with schizophrenia spectrum disorders (SCZ). As U.S. states legalize cannabis and products increase in potency, it is crucial to better understand recent [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) patterns in SCZ. We conducted a scoping review of research on cannabis quantity, frequency, or type in SCZ after January 2016 and present a case series of cannabis use in inpatients with psychosis (2023-2024). Scoping review: Of 672 references, ten studies (2631 participants) were included; none were designed to characterize cannabis quantity, frequency, or type of use over time. Cannabis measurement methodology varied; most studies did not use standardized measures. Frequency and quantity of use at baseline were reported by most studies and these ranged widely. At least a minority of participants with SCZ in each study used cannabis very frequently; quantity of used ranged widely from 0.6 ± 0.6 to 3.4 ± 2.2 joints/day. One small study de Dr. Caplan’s Take “This is a development worth tracking. The clinical implications will become clearer as more evidence accumulates.” Clinical Perspective 🧠 Clinicians should review this item in the context of their current practice and patient population. 💬 Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion →](https://cedclinic.com/interact/discussion-forums/forum/cannabis-industry/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Cannabis%20use%20patterns%20in%20first%20episode%20psychosis%20and%20schizophrenia%3A%20A%20scoping%20review%20and%20case%20series...%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Fcannabis-use-patterns-in-first-episode-psychosis-and-schizophrenia-a-scopin%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fcannabis-use-patterns-in-first-episode-psychosis-and-schizophrenia-a-scopin%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Cannabis%20use%20patterns%20in%20first%20episode%20psychosis%20and%20schizophrenia%3A%20A%20scoping%20review%20and%20case%20series...%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Fcannabis-use-patterns-in-first-episode-psychosis-and-schizophrenia-a-scopin%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) 📰 Source: [https://pubmed.ncbi.nlm.nih.gov/41795326/](https://pubmed.ncbi.nlm.nih.gov/41795326/) Table of Contents - [FAQ](#FAQ)[Why study cannabis use patterns in people with schizophrenia?](#Why_study_cannabis_use_patterns_in_people_with_schizophrenia) - [What did this scoping review and case series include?](#What_did_this_scoping_review_and_case_series_include) - [How much cannabis did people with schizophrenia use in these studies?](#How_much_cannabis_did_people_with_schizophrenia_use_in_these_studies) - [Did the studies measure cannabis use in a consistent way?](#Did_the_studies_measure_cannabis_use_in_a_consistent_way) - [Related](#Related) ## FAQ ### Why study cannabis use patterns in people with schizophrenia? Cannabis use is associated with the development of psychosis and with symptom relapse in people with schizophrenia spectrum disorders. As U.S. states legalize cannabis and products increase in potency, the authors consider it crucial to better understand recent cannabis use patterns in this group. ### What did this scoping review and case series include? The scoping review covered research from after January 2016 on the quantity, frequency, or type of cannabis used by people with schizophrenia spectrum disorders. Of 672 references, ten studies with 2,631 participants were included. The paper also presents a case series of inpatients with psychosis from 2023 to 2024, and it appeared in the Journal of Psychiatric Research. ### How much cannabis did people with schizophrenia use in these studies? Use varied widely. At least a minority of participants with schizophrenia spectrum disorders in each study used cannabis very frequently. Reported quantities ranged from 0.6 ± 0.6 to 3.4 ± 2.2 joints per day across studies, and baseline frequency and quantity, reported by most studies, also ranged widely. ### Did the studies measure cannabis use in a consistent way? No. Cannabis measurement methods varied across studies, and most did not use standardized measures. None of the ten included studies was designed to characterize cannabis quantity, frequency, or type of use over time. [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).