Prospective Evaluation on Cognitive Function and Its Associated Genetic Vulnerability in Cannabis Users

NCT04373525 | Completed

• 1 other identifier: UW 20-189
• Study Type: observational
• Target: 110
• Locations: 1 country
• Sites: 1

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.

Conditions

Neurocognitive Dysfunction; Genetic Predisposition; Cannabis Use

Keywords

Cannabis; Cognition; Genetics

Outcome Measures

Primary Outcomes (4)

• Montreal Cognitive Assessment

  Subject assessed with a maximum score of 30. Those who score 26 or below will consider to have mild cognitive impairment

  18 months

• Frontal Assessment Battery

  Subject who scores 12 or below will be considered having frontal dysexcutive function

  18 months

• Wechsler Memory Scale

  Subject will be assessed with the scale for their immediate, delayed, visual and auditory memory

  18 months

• Genome analysis

  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

  Each subject only need to have venous blood test once 1 day within their 18-months study period

Interventions

Genome analysis OTHER

Venous blood will be obtained for later genome analysis

Eligibility Criteria

• Age: 16 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

16-60 years old cannabis users

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• The University of Hong Kong: lead

Study Sites (1)

Queen Mary Hospital

Hong Kong, 000000, Hong Kong

Location

Biospecimen

Retention: SAMPLES WITH DNA

venous blood sample

MeSH Terms

Conditions

Cognition Disorders; Genetic Predisposition to Disease; Marijuana Abuse

Interventions

Genome-Wide Association Study

Condition Hierarchy (Ancestors)

Neurocognitive Disorders; Mental Disorders; Disease Susceptibility; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Substance-Related Disorders; Chemically-Induced Disorders

Intervention Hierarchy (Ancestors)

Epidemiologic Research Design; Epidemiologic Methods; Investigative Techniques; Molecular Epidemiology; Genetic Association Studies; Genetic Techniques; Oligonucleotide Array Sequence Analysis; Sequence Analysis; Public Health; Environment and Public Health

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Assistant Professor

Study Record Dates

• First Submitted: April 23, 2020
• First Posted: May 4, 2020
• Study Start: November 1, 2020
• Primary Completion: August 31, 2025
• Study Completion: December 31, 2025
• Last Updated: March 27, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

HK (1)