Building upon last month’s review of the endocannabinoid system (Buckland & Cunningham, 2013), we now take a closer look at marijuana, which, according to the National Institute on Drug Abuse, is the most commonly used illegal and addictive drug worldwide (http://www.drugabuse.gov/drugs-abuse/marijuana). Unfounded scare tactics from the early 1900s, as well as social acceptance for this drug, have created a false sense of security regarding its use. How does marijuana work in the human brain, and are there reasons for concern?
Marijuana is usually smoked, so it reaches the brain quickly and its effects can last for a couple of hours. Cocaine and amphetamine act directly on dopamine (DA) nerve terminals, leading to euphoria; whereas opioids, ethanol, and marijuana act on receptors located on GABA nerve terminals to increase dopamine levels. The psychoactive ingredient in marijuana is tetrahydrocannabinol (THC), though marijuana contains hundreds of other known compounds,...