The investigators propose an imaging study to investigate the neurobiological effects of CBD
(vs placebo) in abstinent subjects with heroin use disorder (HUD). The purpose of the study
is to determine the neural circuits and transmitters associated with the effects of CBD on to
reduce craving and anxiety. The neuroimaging will be conducted in participants immediately
following their first administration of CBD (800mg or placebo) and one week after the last
administration (3 daily doses). This CBD administration protocol was shown in previous
studies by the investigators to reduce craving and anxiety in abstinent heroin users.