Cannabinoid-Opioid Interactions

The growing use of cannabis in western societies is of significant concern especially considering that its consumption has increased in teens who are most at risk for developing addictive disorders and other psychiatric illnesses linked to early cannabis exposure. Unfortunately recent years have also seen a surge in the abuse of opioid drugs, a phenomenon often predated by early cannabis use. Moreover, many abusers find greater reward by combining use of cannabis with opioids such as heroin. These patterns suggest possible synergistic interactions between cannabinoid and opioid systems underlying addiction and related psychiatric disorders. This chapter reviews neurobiological systems relevant to reward, motivation and emotional regulation in which cannabinoids and opioids interact.