Cannabis use in patients with early psychosis is associated with alterations in putamen and thalamic shape

Evaluation of a Cannabis Harm Reduction Intervention for People With First-Episode Psychosis: Protocol for a Pilot Multicentric Randomized Trial

BACKGROUND

Cannabis use is highly prevalent in young people with first-episode psychosis (FEP). Most report cannabis use and are often diagnosed with a cannabis use disorder upon admission to specialized services for psychosis. Cannabis use in this population is associated with worse clinical and psychosocial outcomes, rendering it an important clinical target. Despite this, few cannabis-specific interventions have been developed for FEP and empirically evaluated through randomized controlled trials. Most evaluated interventions have targeted cannabis abstinence, with limited efficacy, but none have centered on harm reduction outcomes for people with FEP who use cannabis. Early intervention services (EIS), the standard of care for FEP, have not successfully addressed problematic cannabis use in people with FEP either. Clinical trials are needed to explore the potential of harm reduction strategies, although these should be preceded by robust pilot studies to establish optimal design and approaches.

OBJECTIVE

Recognizing the need for harm reduction strategies for individuals with FEP who use cannabis and based on research on patients' preferences supporting harm reduction interventions, we developed a mobile app-based cannabis harm reduction intervention for this population. This intervention is called Cannabis Harm-reducing Application to Manage Practices Safely (CHAMPS). Here, we describe the protocol for a multicenter, 2-arm, parallel group, randomized pilot trial evaluating the acceptability of CHAMPS for people with FEP who use cannabis and the feasibility of conducting a full-scale trial in this population using CHAMPS. The impact on key clinical outcomes will also be explored.

METHODS

This pilot trial aims to recruit 100 young people with FEP using cannabis from 6 Canadian EIS clinics. Participants will be randomized in a 1:1 ratio to CHAMPS+EIS or EIS-only. CHAMPS acceptability will be assessed using completion rates for the intervention arm. Trial feasibility will be assessed using a retention rate for randomized participants. Secondary outcomes will explore tendencies of change in the use of protective behavioral strategies and in motivation to change strategies. Exploratory outcomes include cannabis use-related problems, other substance use, the severity of dependence, psychotic symptoms, and health care service use.

RESULTS

Recruitment began in December 2021. Data collection and analysis are expected to be completed in early 2024. Study results describing CHAMPS acceptability and trial feasibility will then be submitted for publication in a peer-reviewed journal.

CONCLUSIONS

CHAMPS uniquely combines evidence-based approaches, patient perspectives, and mobile health technology to support harm reduction in people with FEP who use cannabis. Attaining adequate acceptability and feasibility through this trial may justify further exploration of harm reduction tools, particularly within the context of conducting a larger-scale randomized controlled trial. This pilot trial has the potential to advance knowledge for researchers and clinicians regarding a feasible and user-acceptable research design in the cannabis and early psychosis fields.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04968275, https://clinicaltrials.gov/ct2/show/NCT04968275.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53094.

Consensus paper of the WFSBP task force on cannabis, cannabinoids and psychosis

OBJECTIVES

The liberalisation of cannabis laws, the increasing availability and potency of cannabis has renewed concern about the risk of psychosis with cannabis.

METHODS

The objective of the WFSBP task force was to review the literature about this relationship.

RESULTS

Converging lines of evidence suggest that exposure to cannabis increases the risk for psychoses ranging from transient psychotic states to chronic recurrent psychosis. The greater the dose, and the earlier the age of exposure, the greater the risk. For some psychosis outcomes, the evidence supports some of the criteria of causality. However, alternate explanations including reverse causality and confounders cannot be conclusively excluded. Furthermore, cannabis is neither necessary nor sufficient to cause psychosis. More likely it is one of the multiple causal components. In those with established psychosis, cannabis has a negative impact on the course and expression of the illness. Emerging evidence also suggests alterations in the endocannabinoid system in psychotic disorders.

CONCLUSIONS

Given that exposure to cannabis and cannabinoids is modifiable, delaying or eliminating exposure to cannabis or cannabinoids, could potentially impact the rates of psychosis related to cannabis, especially in those who are at high risk for developing the disorder.

Aberrant hippocampal shape development in young adults with heavy cannabis use: Evidence from a longitudinal study

Cannabis is one of the most commonly used illicit drugs globally. Mounting evidence indicates that cannabis use, particularly consumption during young adulthood, is related to adverse mental and behavioral outcomes and an increased risk of the onset and relapse of psychosis. However, the neuromechanism underpinnings of heavy cannabis use (HCU) in young adults remain largely unknown, and no study has yet investigated the development of hippocampal shape in young adults with HCU. Twenty young adults with HCU and 22 matched non-cannabis-use healthy controls (HCs) were enrolled. Neuroimaging scanning and clinical assessments for all participants were performed at baseline (BL) and 3-year follow-up (FU). The vertex-wise shape analysis was conducted to investigate aberrant hippocampal shape development in young adults with HCU. Aberrant shape development pattern of the hippocampus was observed in young adults with HCU. There was no significant difference in hippocampal shape between the groups at BL, but young adults with HCU at FU exhibited significant shape atrophy of the right dorsal anterior hippocampus related to HCs. In addition, there was a significantly lower growth rate of the right hippocampal shape. Furthermore, there were significant associations of heavy cannabis use, as indicated by the age at onset first and frequent cannabis use, with the growth rate of hippocampal shape in young adults with HCU. The aberrant hippocampal shape development may reflect the effect of heavy cannabis use on young adults and it may be a potential target for heavy cannabis use treatment for young adults.