Behavioral Pharmacology of THC and D-limonene

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, 12-lead ECG 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 (THC, d-limonene). 9. Report having experienced anxiety after consuming cannabis in the past. 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 over the counter, 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 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. 5. Use of dronabinol (Marinol®) within the past month. 6. Average use of cannabis more than 2 times per week in the prior 3 months. 7. History of clinically significant cardiac arrhythmias or vasospastic disease (e.g., Prinzmetal's angina). 8. Abnormal EKG result that in the investigator's opinion is clinically significant. 9. Enrolled in another clinical trial or have received any drug as part of a research study within 30 days prior to dosing. 10. Having previously sought medical attention to manage adverse effects following acute cannabis use. 11. Individuals with anemia or who have donated blood in the prior 30 days