This study will evaluate the pharmacokinetics and pharmacodynamics of vaporized b-myrcene and THC administered via inhalation.

The proposed study will be conducted at the Johns Hopkins Behavioral Pharmacology Research Unit (BPRU). Participants will complete 9 acute drug administration periods in which they will administer THC alone, myrcene alone, THC and myrcene together, or placebo. Subjective drug effects and vital signs will be assessed following drug administration. Each participant will receive all 9 dose conditions in a randomized order using a placebo controlled within-subject crossover design. The study will help us understand the individual and interactive effects of THC and b-myrcene, two common constituents found in cannabis.

Inclusion Criteria:

1. Have provided written informed consent
2. Be between the ages of 18 and 55
3. Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
4. Test negative for drugs of abuse other than cannabis, including breath alcohol at the screening visit and at clinic admission
5. Not be pregnant or nursing (if female). All females must have a negative serum pregnancy test at the screening visit and a negative urine pregnancy test at clinic admission.
6. Have a body mass index (BMI) in the range of 18 to 36 kg/m2
7. Blood pressure at Screening Visit does not exceed a systolic blood pressure (SBP) of 150 mmHg or a diastolic blood pressure (DBP) of 90 mmHg
8. Have no allergies to any of the ingredients used to prepare vapor (delta 9-THC, myrcene).
9. Demonstrate competency on cognitive performance measures at screening visit (e.g., PASAT score over 75).

Exclusion Criteria:

1. Non-medical use of psychoactive drugs other than, nicotine, alcohol, or caffeine 3 month prior to the Screening Visit;
2. History of or current evidence of significant medical (e.g. seizure disorder) or psychiatric illness (e.g. psychosis) judged by the investigator to put the participant at greater risk of experiencing an adverse event due to exposure or completion of other study procedures.
3. Use of an OTC, systemic or topical drug(s), herbal supplement(s), or vitamin(s) within 14 days of experimental sessions; which, in the opinion of the investigator or sponsor, will interfere with the study result or the safety of the subject.
4. Use of a prescription medication (with the exception of birth control prescriptions) within 5 half-lives for that specific drug; which, in the opinion of the investigator or sponsor, will interfere with the study result or the safety of the subject.
5. Cannabis use that is inconsistent with protocol requirements.
6. Clinically significant cardiac arrhythmias or vasospastic disease (e.g., Prinzmetal's angina).
7. Individuals with anemia or who have donated blood in the prior 30 days

placebo controlled, double blind