Cannabis Use, Cognition, and the Endocannabinoid System in HIV

Overview

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]
• change in Human Temporal Bisection Task score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in Probabilistic Learning Task score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in Progressive Ratio Task score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in Continuous Performance Task score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in human Behavioral Pattern Monitor activity and exploration score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in prepulse inhibition percentage score from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in cerebrospinal fluid (CSF) anandamide (AEA) quantity from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in cerebrospinal fluid (CSF) 2-Arachidonoylglycerol (2-AG) quantity from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]
• change in cerebrospinal fluid (CSF) homovanillic acid (HVA) quantity from baseline to post-intervention [Time frame: baseline and 5 days after drug initiation]

Eligibility criteria

Inclusion criteria

• Aged 18-65
• 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
• Pregnancy
• 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Basic science

Study locations

United States · 1 center

• UC San Diego Medical Center-Hillcrest — San Diego

Identifiers

NCT: NCT04883255 · 210323 · R01DA051295

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗