All participants will be healthy volunteers and all procedures will be completed for research
purposes only. Two groups will be recruited, females who use cannabis (marijuana, MJ), and
female who do not use cannabis (controls). Female MJ users will be enrolled in a protocol
that includes an outpatient drug administration session and a 4-day/3-night inpatient stay on
the Johns Hopkins Bayview Clinical Research Unit (CRU). During outpatient visits, MJ users
will have an MRI, and complete MJ self-administration and cognitive performance sessions. MJ
users will then reside on the CRU,and complete MJ abstinence, and self-report instruments for
withdrawal discomfort. A positron emission tomography (PET) scan of brain cannabinoid type 1
receptors will also be completed. Non-users will complete MRI, PET imaging and cognitive
testing under an outpatient protocol (no MJ administration).