THC sleep study: frequent vs. rare users under the microscope
NCT ID NCT03560934
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study looked at how a pill form of THC (dronabinol) affects sleep and thinking in 18 adults. Some participants used cannabis frequently (more than 3 times a week), while others rarely used it (less than 10 times ever). Researchers measured sleep stages, alertness, memory, and heart health over a 4-day hospital stay. The goal was to understand THC's effects, not to treat a disease.
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Study facts
What this study's own registry entry says, in plain language.
- Phase
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Early phase 1
The earliest testing in people: a first look at safety, in a very small group.
- Participants
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18 people
The number who actually took part.
- Started
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Sep 2018
- Finished
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Dec 2025
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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21 to 34 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Frequent Cannabis Use (\>3x/week for the prior 3 months) or * No Cannabis Use (Less than 10x ever) Exclusion Criteria: * Sleep Apnea * Pregnancy * Diabetes * Cardiovascular disease * Chronic Pain * History of seizures * Severe Hepatic impairment * Conditions associated with clinically relevant cognitive impairment * Symptoms of acute or active illness (e.g., fever and leukocytosis) * Evidence of psychopathology on the Beck Depression Index II (BDI-II or in a structured clinical interview with a physician * History of severe psychiatric illnesses (including such as alcoholism, drug dependency including a cannabis use disorder score ≥12 on the Cannabis Use Disorders Identification Test (CUDIT) (28) or \>1 withdrawal symptom on the Marijuana Withdrawal Checklist (MWC (29)) , major depression, manic depressive illness, schizophrenic disorders, panic disorder, generalized anxiety disorder, post-traumatic stress disorder, agoraphobia, claustrophobia, paranoid personality disorder, schizoid personality disorder, schizotypal personality disorder, borderline personality disorder, and antisocial personality disorder.) * History of having been treated with antidepressants, neuroleptic medications, or tranquilizers. * Volunteers must be drug-free (including caffeine, nicotine, alcohol and herbal medications) for the duration of the screening and study period (with the exception of THC), with no dependence on drugs (e.g. cocaine, opioids, amphetamine, methamphetamine, PCP, benzodiazepines, barbiturates, methadone, MDMA); or alcohol dependency. * Current Nicotine use ( or history of more than 5 'pack years' of smoking) * Current use of prescription or over the counter medications * History of shift work in the last 6 months * Travel across \>2 time zones during the month prior to the study * Habitual bedtime after 1am or waketime before 5am
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Oregon Health & Science University
Portland, Oregon, 97239, United States
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Other studies related to the condition(s) this trial covers.
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