Symposium​​ 
S05 -​​ 
Cannabis Use and Psychosis: Diagnosis and Management​​ 

Saturday, 24 October​​ 
13:30 – 16:45 (3 hrs plus 15 min break
)

David Crockford*, MD, FRCPC; Phil Tibbo, MD, FRCPC; Tom Hastings, MD, FRCPC​​ 

 

CanMEDS Roles:​​ 

  • Medical Expert​​ 

  • Communicator​​ 

  • Health Advocate​​ 

At the end of this session, participants will be able to:​​ 1) Understand the relationship between cannabis use and psychosis; 2) Distinguish primary psychoses from cannabis induced psychoses and know how to manage them; and 3) Implement appropriate psychosocial interventions for cannabis use in persons with psychosis.​​ 

Population based studies demonstrate that cannabis use in youth and young adults is associated with the development of psychosis. Earlier age of regular cannabis use, increased frequency of use, and higher cannabis potency appear to significantly increase the development of psychosis. Cannabis use is considered a preventable and independent risk factor for psychosis development by many in the medical community. Additionally, continued cannabis use after the onset of psychosis is reported to significantly worsen the recovery process and long-term outcomes of these young adults. Cannabis use is common in persons presenting for early psychosis treatment where up to 2/3rds meet criteria for a cannabis use disorder. Clinicians treating persons at risk for developing psychosis or after a first episode of psychosis typically recommend not using or, at least, reducing cannabis to potentially minimize developing psychosis, needing antipsychotic medication, or worsening psychosis outcomes. Early intervention services (EIS) for psychosis identify improved understanding of cannabis misuse, its diagnosis and management as a priority for research and clinical care. This symposium will: 1) review the recent literature on the relationship between cannabis and psychosis; 2) present and discuss a clinical order set to aid in the standardization of diagnosis and treatment of cannabis related psychosis; and finally 3) start a discussion on what and how to do psychosocial interventions for cannabis related psychosis.

S05a - Cannabis and Psychosis
Phil Tibbo*, MD, FRCPC​​ 

At the end of this session, participants will be able to:​​ 1) Appreciate the research literature regarding cannabis, endocannabonoid system and the brain; 2) Understand the potential outcomes of regular cannabis use during adolescence and young adulthood, including at risk populations; and 3) Appreciate the prevalence of substance use in early phase psychosis and the need for treatment options.​​ 

A common viewpoint has proliferated in the media and general public that cannabis use is mostly harmless. Additionally, some argue that by not supporting its use we are missing a great therapeutic opportunity for chronic medical conditions The view that cannabis is void of negative effects may partially be a result of minimal efforts in, or ineffective, knowledge translation in this area. In fact, the “war on drugs” approach has not allowed for basic education on the varied effects of cannabis on the brain, especially at highly critical phases of brain development.​​ 

This first talk of the symposium will synthesize the literature on the effects of cannabis on the developing young adult brain in the context of mental health, with a focus on early phase psychosis. Variables such as motivations to use, potency of product used, age of use, at-risk populations, genetics and sex differences will be discussed. Additionally, studies investigating potential therapeutic uses of cannabis and cannabinoid products for psychosis will be presented. This talk will give the necessary background for the remaining symposium; development of standardized approaches to comorbid cannabis misuse and psychosis, pharmacological and non-pharmacological approaches to care.

References:

 

  • Crocker C, Tibbo P. Cannabis and the maturing brain: role in psychosis development. Clinical Pharmacol Ther 2015;97(6):545–7.

  • Crocker CE, Tibbo P. The interaction of gender and cannabis in early phase psychosis. Schizophr Res 2018;194;18–25.

 

S05b - The Cannabis and Psychosis Clinical Order Set
Tom Hastings*, MD, FRCPC​​ 

At the end of this session, participants will be able to:​​ 1) Explain the process by which the Cannabis and Psychosis Clinical Order Set was developed; 2) Implement the Cannabis and Psychosis Clinical Order Set in their practice; and 3) Diagnose and treat cannabis related psychosis in a standardized fashion.​​ 

Order sets are grouped medical orders/check lists relating to a particular condition and can be used to assist clinicians in providing high-quality, evidence-based standardized care relating to the assessment and/or treatment of that condition. The Canadian Consortium for Early Intervention in Psychosis (CCEIP) is partnering with Think Research to develop order sets, intended for use with early phase psychotic disorders. The CCEIP has developed a library of clinical order sets including ones for the initiation and optimization of treatment of early phase psychosis (EPP), as well as for the initiation of Clozapine in the EPP setting. Currently, funded by a Health Canada Substance Use and Addictions Program grant, CCEIP has been working on a project, The development and dissemination of a clinical order set to address the diagnosis and treatment of cannabis induced psychosis. The primary objective for the development and implementation of this cannabis focused clinical order set is to promptly and successfully identify, diagnose and treat cannabis induced psychosis in youth (in general) as well as in those youth and young adults already in care in early intervention services for psychosis. The​​ cannabis order set has gone thru development stages including a national needs survey, collation and organization of clinical content, reference collection and review of current guidelines and protocols by a national faculty, drafting and editing order set with recent pilot data collected. The process, national needs survey and order set itself will be presented and discussed.

References:

S05c - Psychosocial Interventions for Cannabis Use in the Context of Psychosis
David Crockford, MD, FRCPC

At the end of this session, participants will be able to:​​ 1) Describe the evidence for psychosocial interventions for cannabis use; 2) Provide psychoeducation around cannabis use and psychosis for patients and family that helps facilitate change; and 3) Implement brief interventions for cannabis use into their day to day clinical practice.​​ 

Cannabis use is an independent risk factor for the development of schizophrenia and other psychoses, where highest risk is for adolescents and young adults who use daily or almost daily, especially high potency cannabis. Cannabis use can also worsen the course of psychosis, resulting in the presence of more hallucinations and delusions, decreased treatment adherence, and more hospitalizations. Cannabis use is common in persons presenting for early psychosis treatment. Clinicians treating persons at risk for developing psychosis or after a first episode of psychosis typically recommend not using or, at least, reducing cannabis to potentially minimize developing psychosis, needing antipsychotic medication, or worsening psychosis outcomes. To date, the only effective interventions for cannabis use involve psychosocial approaches, where brief interventions appear to have beneficial effects similar to more extensive psychosocial interventions, yet are more cost effective and more easily translated into daily practice. Brief interventions are modeled on motivational interviewing (MI), but are more advice driven and designed to be delivered by individuals without specific training in MI or addictions. Evidence for brief interventions, MI, and CBT will be reviewed. Psychoeducational talking points will be discussed including low-risk cannabis use guidelines and how to perform a brief intervention for cannabis use in the person suffering from psychosis will be demonstrated.

References:​​ 

  • Crockford D, Addington D. Canadian Schizophrenia Guidelines: Schizophrenia and Other Psychotic Disorders with Coexisting Substance Use Disorders. Can J Psychiatry 2017;62:624-634.

  • Parmar A, Sakar S. Brief Interventions for Cannabis Use Disorders: A Review. Addict Disord Their Treatment 2017;16:80-93.

 

/ Virtual Conference 2020