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Change in Cognitive Function in Stimulant Users (SToP-S_CogFx)

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. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04061941
Recruitment Status : Recruiting
First Posted : August 20, 2019
Last Update Posted : November 23, 2021
Beat Drugs Fund Association
Information provided by (Responsible Party):
Dr. Albert Kar-Kin Chung, The University of Hong Kong

Brief Summary:

In Hong Kong, methamphetamine use is common and cocaine use has increased steadily over the past few years. While the use of ketamine decreased from 35.8% in 2015 to 13.9% in 2017, methamphetamine and cocaine have become the most commonly used psychotropic substances and account for more than 50% of drug abuses cases in 2017. Among all stimulants, methamphetamine is most commonly used because it releases three times more dopamine than cocaine and the effects can last from eight to twelve hours, compared to two hours for cocaine. On top of its extreme effects, methamphetamine is relatively inexpensive, making it even more accessible to the young population.

Misuse of methamphetamine has long been associated with profound psychological and cognitive disturbance. In reviewing the cognitive data from reasonably well-matched groups of chronic methamphetamine users and healthy controls, the majority of studies have found that chronic methamphetamine users had lower scores on at least some cognitive tests, although some studies are exceptions with entirely nonsignificant differences. A meta-analysis of 17 cross-sectional studies found that chronic methamphetamine users demonstrated significantly lower cognitive scores than healthy controls. The effects were largest for measures of learning, executive functions, memory, and processing speed, although the majority of cognitive domains significantly differed between the groups.

Concerns has been emerging regarding the methodology of the aforementioned results. In particular, the appropriateness of using healthy controls to examine the cognitive effects of stimulant use has been questioned. Much of the published research has fallen victim to using controls with significant baseline differences from the chronic stimulant users, such as years of education. In addition, none of the studies available provided scatter plots of their cognitive data to evaluate the overlap in performance between chronic stimulant users and healthy controls. In fact, many chronic stimulant users have normal cognitive function when compared with normative data. Therefore, the use of the term 'impairment' or 'deficit' in many studies is not fully justified. Another limitation is that it cannot differentiate cognitive weaknesses that may predate stimulant use from those that result from it. Notably, longitudinal studies have shown that childhood deficits in executive function can predict drug abuse in adolescence, suggesting that at least some of the cognitive weaknesses pre-exist in chronic stimulant user. These and other limitations provoked a conclusion that the evidence for cognitive deficits in chronic stimulant users is weak.

In order to overcome the methodological issues observed in previous cross-sectional studies, we propose to conduct a prospective studies to determine the change in cognitive function among stimulant users over time.

Condition or disease Intervention/treatment
Cognitive Dysfunction Stimulant Use Methamphetamine Abuse Cocaine Use Substance Use Behavioral: Cognitive Assessment

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Study Type : Observational
Estimated Enrollment : 120 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: A Prospective Study to Evaluate the Change in Cognitive Function in Stimulant Users
Actual Study Start Date : October 21, 2019
Estimated Primary Completion Date : December 31, 2022
Estimated Study Completion Date : December 31, 2023

Group/Cohort Intervention/treatment
Stimulant Users
Stimulant users that fulfill SCID-5 clinician version definition for assessment on stimulant use disorder under DSM-5
Behavioral: Cognitive Assessment
Assessment on cognitive dysfunction using standardised cognitive tests

Primary Outcome Measures :
  1. Montreal Cognitive Assessment [ Time Frame: 12 months ]
    Measure the change in global cognitive function

  2. Frontal Assessment Battery [ Time Frame: 12 months ]
    Measure the change in executive function

  3. Diagnostic and Statistical Manual of mental disorders 5th edition (DSM-5 )severity of stimulant use disorder [ Time Frame: 12 months ]
    To determine different severity of stimulant use

Secondary Outcome Measures :
  1. Frequency of stimulant use [ Time Frame: 12 months ]

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.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
stimulant users who have been taking stimulants regularly

Inclusion Criteria:

  • Age: 18 - 65 years old at the time of enrolment
  • Able to read and communicate in English and/or Chinese
  • Able to give informed consent
  • Using stimulants as the primary psychoactive substance of abuse
  • "Repeated" and "Active" stimulant users as defined by Structured Clinical Interview for DSM-5 Disorders (SCID-5)

Exclusion Criteria:

  • Age <18 years old
  • Unable to read English or Chinese
  • Unable to give informed consent
  • Had been diagnosed with other Substance Use or Related Disorders with severity ≥4 according to DSM-5, or other psychoactive substance dependence syndrome according to International Classification of Disease (ICD-10)
  • Currently taking regular prescribed psychiatric medications, including antipsychotics, antidepressants, mood stabilizers, anti-epileptics, benzodiazepines, hypnotics, and anti-cholinergic medications.
  • Had been diagnosed with other DSM-5 disorders including:

    • Neurodevelopmental Disorders
    • Schizophrenia Spectrum and Other Psychotic Disorders
    • Bipolar and Related Disorders
    • Depressive Disorders, Anxiety Disorders, and Obsessive-Compulsive and Related Disorders
    • Dissociative Disorders, Somatic Symptoms and Related Disorders
    • Feeding and Eating Disorders
    • Sleep-wake Disorders
    • Neurocognitive 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): NCT04061941

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Contact: albert KK Chung, MBBS(HK) 2255 4486

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Hong Kong
Queen Mary Hospital Recruiting
Hong Kong, Hong Kong, 000000
Contact: Albert KK Chung         
Sponsors and Collaborators
The University of Hong Kong
Beat Drugs Fund Association
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Responsible Party: Dr. Albert Kar-Kin Chung, Clinical Assistant Professor, The University of Hong Kong Identifier: NCT04061941    
Other Study ID Numbers: BDF180058
First Posted: August 20, 2019    Key Record Dates
Last Update Posted: November 23, 2021
Last Verified: November 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Substance-Related Disorders
Cognitive Dysfunction
Chemically-Induced Disorders
Mental Disorders
Cognition Disorders
Neurocognitive Disorders