The purpose of this research is to assess the effects of smoked cananbis when cannabis is smoked during periods of cannabis use as usual and after a brief period of abstinence.

This outpatient study will assess the acute pharmacodynamic effects of smoked cannabis with ~50 mg and ~100 mg THC compared to placebo (~0 mg THC) and whether a brief period of abstinence alters these effects. Metabolism (pharmacokinetics) of THC will be examined to associate behavioral and physiological effects to plasma concentrations of THC and metabolites.

Inclusion Criteria:

• • Male or non-pregnant and non-lactating females aged 21-55 years

  • Report cannabis smoking near daily
  • Not currently seeking treatment for their cannabis use
  • Have a Body Mass Index from 18.5 - 34kg/m2.
  • Able to perform all study procedures
  • Must be using a contraceptive (hormonal or barrier methods)

Exclusion Criteria:

• Meeting DSM-V criteria for any substance use disorder other than cannabis, nicotine, caffeine
• Do not have positive urine toxicology for cannabis use during screening
• Evidence of severe psychiatric illness (e.g. mood or anxiety disorder with functional impairment or suicide risk, schizophrenia) judged by the study physician (and PI) to put the participant at greater risk of experiencing adverse events due to completion of study procedures, interfere with their ability to participate in the study, or their capacity to provide informed consent.
• Report using other illicit drugs in the prior 4 weeks
• Current predominant licit use of medical cannabis, prescription analgesics, or any medications that may affect study outcomes
• Current pain
• Pregnancy
• Currently enrolled in another research protocol
• Not using a contraceptive method (hormonal or barrier methods)
• Insensitivity to the cold water stimulus of the Cold Pressor Test
• Any disorders that might make cannabis administration hazardous as determined by evaluation physician after review of all medical assessments along with medical history.
• Not able to speak and read English