What has long been known empirically has been confirmed scientifically.
Although evident for centuries, the adverse effects of marijuana use have been ignored and often denied by the cognoscenti of “weed.”
Ignored has been its classification as a hallucinogenic, Schedule 1 drug under the Controlled Substance Act of 1970 and the Marijuana Tax Act of 1937.
Ignored has been the vast scientific literature concerning its effect on the immune system. And ignored has been the amotivational syndrome and detrimental effects upon youth. (But space is limited to be able to more adequately delve further.)
A recent study by Jodi Gilman, professor of psychiatry at Harvard Medical School, and Hans Breiter, from Massachusetts General Hospital, using the most modern equipment with which to image brain function made some amazing discoveries.
In a study comparing nonsmokers with casual recreational smokers (one joint, at least, per week, but in no way showing any signs of addiction or habituation), all participants were 18 to 25 years of age. The participants insisted only casual users be in the study.
There were significant differences in many parts of the brain among users and nonusers. Brain regions related to decision-making, motivation and emotional processing in users were affected at the time their brains were still developing. The differences in the nucleus accumbems and amygdala were significant and noteworthy.
Marijuana use in the young creates a hole in the human psyche. Whether this can be reversed by abstinence or age has yet to be determined.