A Laboratory Model of Increasing Delta-9-tetrahydrocannabinol (THC) Potency on Cigarette Smoking

The study requires a total of three visits to Battelle's laboratory: one screening visit and
two experimental visits. The screening visit will determine eligibility into the study. If
eligible, participants will smoke a tobacco cigarette through the Clinical Research Support
System (CReSS) puff topography device. Enrolled participants will attend two separate 5-hour
experimental visits. Participants will be randomly assigned the order of THC potency (active
or placebo), with the assignment blocked by sex. When participants arrive at the laboratory
for each visit, they will provide biologic samples to verify compliance with pre-study
instructions and then will be taken to a specially ventilated smoking chamber. They will be
connected to a continuously-monitoring heart rate and blood pressure machine so that their
vital signs can be observed throughout the smoking session. A research assistant will give a
marijuana cigarette to the participant. A research assistant will light the cigarette and
then exit the room. Participants will follow tape-recorded instructions for smoking the
marijuana cigarette through the CReSS device. Upon completion of smoking the marijuana
cigarette, participants will complete the Tobacco Craving Questionnaire via paper and pencil
and will then be allowed to smoke one of his own tobacco cigarettes through the CReSS puff
topography device. Participants will be allowed to smoke as many tobacco cigarettes as they
would like for the next 3 hours. Participants will then be given lunch and sent home via
taxicab. All participants will receive both potencies (i.e., active and placebo) of
marijuana. The active potency of marijuana will be 5.6% THC.

Inclusion Criteria:

1. Current US resident;

2. Age ≥ 18 years;

3. Self-reported smoking of marijuana no more than three days per week within the past
year;

4. Self-report past-month smoking of marijuana;

5. Self-report daily smoking of at least five cigarettes per day within the past year;

6. Cotinine ≥ 100 ng/mL at the in-person screening visit; and

7. Able to read, understand, and sign informed consent.

Exclusion Criteria:

1. Meets Diagnostic and Statistical Manual-5 (DSM-5) criteria for current (i.e., past
year) or past (i.e., lifetime) cannabis use disorder;

2. Meets DSM-5 criteria for any current Axis I disorder, other than tobacco use disorder;

3. Self-reported current desire to stop marijuana or tobacco use, defined as 7 or greater
on an 11-rung (scaled of 1-10) Contemplation Ladder for each;

4. Self-reported asthma or chronic obstructive pulmonary disease; and

5. Among females, current pregnancy or lactation.