NCT04883255 · University of California, San Diego
Cannabis Use, Cognition, and the Endocannabinoid System in HIV
What this study is about
Understanding how co-morbidities in persons with HIV (PWH) such as substance use affect risk-taking, decision-making, and other cognitive behaviors is important given implications for everyday functioning and transmission risk. The high prevalence of cannabis use in PWH, medicinally and recreationally, may indicate disease severity, impart therapeutic benefits, or adverse consequences.
View original scientific description
Understanding how co-morbidities in persons with HIV (PWH) such as substance use affect risk-taking, decision-making, and other cognitive behaviors is important given implications for everyday functioning and transmission risk. The high prevalence of cannabis use in PWH, medicinally and recreationally, may indicate disease severity, impart therapeutic benefits, or adverse consequences. In fact, cannabis is recommended to those with HIV to alleviate nausea, improve appetite, relieve pain, and lift mood. To-date, the consequences of cannabis use in PWH remain unclear as do potential interactions with HIV treatments. In healthy participants, heavy cannabis use is associated with cognitive deficits e.g., risky decision-making, response disinhibition and inattention, but pro-cognitive effects in PWH may exist at mild use levels due to its anti-inflammatory and anti-excitotoxic properties. Furthermore, little has been done to determine the effects of cannabis use on the endocannabinoid (EC) system in general or in PWH. This study will determine the effects of the two primary cannabis constituents (Δ9-tetrahydrocannabinol \[THC\], cannabidiol \[CBD\]) vs. placebo on risky decision-making, response inhibition, reward learning, temporal perception, and motivation, plus EC and homovanillic acid (HVA; a surrogate for dopamine activity) levels in HIV+ and HIV- subjects. Participants with infrequent cannabis use will undergo baseline cognitive testing and biomarker assays with antiretrovirals (ART) use quantified. They will be randomized to a 5-day course of either THC, CBD, or placebo and return for follow-up testing and re-assaying of ECs and HVA levels.
Interventions
DRUG
10 mg Δ9-tetrahydrocannabinol (THC)
5-day course of orally-administered THC (dronabinol), 10 mg
DRUG
600 mg cannabidiol (CBD)
5-day course of orally-administered CBD, 600 mg
DRUG
Placebo
5-day course of orally-administered placebo
Primary outcome measures
change in Iowa Gambling Task score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower scores reflect increased risk-taking
change in Human Temporal Bisection Task score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Scores reflect fast or slow perception of timing.
change in Probabilistic Learning Task score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower scores reflect poorer learning.
change in Progressive Ratio Task score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower scores reflect lower motivation or willingness to work for a reward.
change in Continuous Performance Task score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower scores reflect worse attention.
change in human Behavioral Pattern Monitor activity and exploration score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Higher scores reflect motor hyperactivity and increased exploration.
change in prepulse inhibition percentage score from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower scores reflect worse sensorimotor gating.
change in cerebrospinal fluid (CSF) anandamide (AEA) quantity from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower AEA signifies less amounts of this endocannabinoid in the central nervous system.
change in cerebrospinal fluid (CSF) 2-Arachidonoylglycerol (2-AG) quantity from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower 2-AG signifies less amounts of this endocannabinoid in the central nervous system.
change in cerebrospinal fluid (CSF) homovanillic acid (HVA) quantity from baseline to post-intervention
Time frame: baseline and 5 days after drug initiation
This is an experimental measure and not a scale with specific anchor points. Lower HVA signifies less amounts of this dopamine metabolite in the central nervous system.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Possess the capacity to provide informed consent to a set of neurobehavioral, neuromedical and cognitive assessment procedures. Individuals unable to provide such consent will not be enrolled into the study.
- Willing to confirm self-reported HIV using a rapid test: HIV status will be determined using the MedMira Rapid Test (Halifax, Nova Scotia, Canada). If the result differs from the participant's self-report a confirmatory Western Blot will be performed.
- Willing to abstain from cannabis for at least 1 week prior to the baseline visit and during the study. Although there is no definitive method for determining abstinence over this period, abstinence will be confirmed as best as possible by using an oral fluid testing device (Draeger 5000) employed by law enforcement officers to detect recent cannabis use. An oral fluid value of \> 5ng suggests recent use, although in some cases it has been reported that individuals may show \> 5ng up to 20 hours after use. Thus, should the oral fluid sample indicate \> 5ng THC, the assessment may be canceled and rescheduled.
Exclusion criteria
- Inability to provide informed consent
- Significant chronic renal disease (unrelated to HIV), significant chronic pulmonary disease (unrelated to HIV), or Hepatitis C Virus infection
- Head injury with loss of consciousness for greater than 30 minutes or resulting in neurologic complications
- Seizure disorder
- Demyelinating diseases or other non-HIV neurological disorders
- Acute or recent or previous clinically disabling stroke or previous cerebrovascular events
- Lifetime history of schizophrenia or other psychotic disorders, or bipolar disorder.
- Beck Depression Inventory-II (BDI-II) score is greater than or equal to 29 (severe depression) or suicidal ideas are endorsed on the BDI-II or a Center for Epidemiological Studies-Depression Scale (CES-D) subscale measuring suicidal ideation
- Substance use disorder (mild, moderate or severe) within the last 12 months
Where
- San Diego, California
Collaborators
National Institute on Drug Abuse (NIDA)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 1, 2026 · Source of record for eligibility and locations