Try the modernized beta website. Learn more about the modernization effort.
Working… Menu

Prospective Evaluation on Cognitive Function and Its Associated Genetic Vulnerability in Cannabis Users (SToP-C_PeCoG)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT04373525
Recruitment Status : Enrolling by invitation
First Posted : May 4, 2020
Last Update Posted : November 23, 2021
Information provided by (Responsible Party):
Dr. Albert Kar-Kin Chung, The University of Hong Kong

Brief Summary:

Most of the studies assessing Cannabis Use Disorder (CUD) and neurocognitive functions are cross-sectional without examining the longitudinal changes in neurocognitive function at a within-subject level with respect to the continuum of cannabis use behavior, or mainly studying on the acute cannabis effect. As for the Genome-wide Association studies, the population analyzed for addressing the underlying genetic susceptibility between neurocognitive functions and/or cannabis use or CUD were almost exclusively based on African- or European- American samples or other Caucasian subjects, and thus generalizability to Chinese or to the non-Caucasian population definitely demands more studies.

With the upsweeping statistical figures of cannabis use in Hong Kong and Asia, and the substantial falls in the perceived risk and personal disapproval from using cannabis amongst young abusers, coinciding the global advocacy of de-criminalizing cannabis and the increased availability of recreational cannabis worldwide, it is reasonable to predict that there will be a further upsurge in numbers of all aged cannabis users in Hong Kong as in the other part of the world. Therefore, the SToP-C-PeCoG study proposed here as a prospective study in assessing the longer term changes in neurocognitive functions and the associated genetic risks for those repeated and active cannabis users without psychiatric co-morbidity is definitely warranted. The PeCoG study will not only provide the scientific evidence to further unveil the harmful effects on neurocognitive functions for those self-perceived "healthy" users, but also help to raise the public awareness and to improve the understandings to the long-term detrimental effects of cannabis amongst users and non-users. Furthermore, it will provide a chance to study the associated genetic risks for cannabis abusers, in particular in the Asian minority and Chinese, on CUD and poorer neurocognitive outcomes, with genetic vulnerability being generalizable to the local population in Asia.

The current study hypothesises that cannabis abusers have neurocognitive function decline over time, and genetic vulnerability is associated with cannabis abusers who have poorer neurocognitive outcomes or with the severity of CUD.

Condition or disease Intervention/treatment
Cannabis Use Neurocognitive Dysfunction Genetic Predisposition Other: Genome analysis

Layout table for study information
Study Type : Observational
Estimated Enrollment : 136 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Substance Misuse To Psychiatric Disorders for Cannabis-Prospective Evaluation on Cognitive Function and Its Associated Genetic Vulnerability in Cannabis Users (SToP-C-PeCoG)
Actual Study Start Date : November 1, 2020
Estimated Primary Completion Date : September 1, 2023
Estimated Study Completion Date : March 31, 2024

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Marijuana

Intervention Details:
  • Other: Genome analysis
    Venous blood will be obtained for later genome analysis

Primary Outcome Measures :
  1. Montreal Cognitive Assessment [ Time Frame: 18 months ]
    Subject assessed with a maximum score of 30. Those who score 26 or below will consider to have mild cognitive impairment

  2. Frontal Assessment Battery [ Time Frame: 18 months ]
    Subject who scores 12 or below will be considered having frontal dysexcutive function

  3. Wechsler Memory Scale [ Time Frame: 18 months ]
    Subject will be assessed with the scale for their immediate, delayed, visual and auditory memory

  4. Genome analysis [ Time Frame: Each subject only need to have venous blood test once 1 day within their 18-months study period ]
    venous blood test will be done on consented subject for genome analysis for associated single nucleotide polymorphisms on 4 related chromosomes identified from literature associated with cannabis use disorder and neurocognitive impairment

Biospecimen Retention:   Samples With DNA
venous blood sample

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   16 Years to 60 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
16-60 years old cannabis users

Inclusion Criteria:

  • Age: 16 - 60 years old at the time of enrolment
  • Able to read and communicate in English and/or Chinese
  • Able to give informed consent
  • Using cannabis or marijuana as the primary psychoactive substance of abuse
  • Repeated and Active cannabis users as defined by Structured Clinical Interview for DSM-5 Disorders

Exclusion Criteria:

  • Age <16 years old
  • Unable to read English or Chinese
  • Unable to give informed consent
  • Had been diagnosed with other Substance Related Disorders, except for Tobacco Use Disorders due to the known frequent comorbid use for cannabis users (12)
  • Currently taking regular prescribed psychiatric medications, including antipsychotics, antidepressants, mood stabilizers, anti-epileptics, benzodiazepines, hypnotics, and anti-cholinergic medications.
  • Had been diagnosed with DSM-5 disorders, other than Cannabis Use and related disorders

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04373525

Layout table for location information
Hong Kong
Queen Mary Hospital
Hong Kong, Hong Kong, 000000
Sponsors and Collaborators
The University of Hong Kong
Layout table for additonal information
Responsible Party: Dr. Albert Kar-Kin Chung, Clinical Assistant Professor, The University of Hong Kong Identifier: NCT04373525    
Other Study ID Numbers: UW 20-189
First Posted: May 4, 2020    Key Record Dates
Last Update Posted: November 23, 2021
Last Verified: November 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: data without identifiable

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Dr. Albert Kar-Kin Chung, The University of Hong Kong:
Additional relevant MeSH terms:
Layout table for MeSH terms
Disease Susceptibility
Genetic Predisposition to Disease
Marijuana Abuse
Cognitive Dysfunction
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Disease Attributes
Pathologic Processes
Cognition Disorders
Neurocognitive Disorders