Marijuana Users Grossly Underachieve

by Dr. Drew W. Edwards

Republished from

All the independent, peer-reviewed research confirms what I and  other experts have observed for years. Cannabis users significantly underachieve in education, their careers, and have significant problems with their most significant relationships. Two recent and eye-opening studies published in the medical journals Addiction, and Neuropharmacology respectively reveal gross deficits in cognitive ability (IQ) executive functioning, attentiveness, inhibition of impulsiveness and motivation.

What the Studies Reveal

In a large prospective study approximately 1900 adolescent were followed and evaluated for 10 years. The results were clear, definitive and shocking. Marijuana users were three times more likely to be unemployed or have dropped out of school compared to non-users. The evidence was so compelling that the lead investigator of the research dubbed marijuana as, “the drug of choice for life’s future losers.” In short, adolescents and young adults who possess the intelligence, desire, and motivation to go on to college or technical school frequently abandon these aspirations for something less rigorous once they begin smoking marijuana.

Hurd and colleagues (2014) demonstrated that even casual cannabis use impairs memory, motivation, and executive functioning, which involves the ability to organize tasks, control impulses and set
priorities. As a result, most marijuana users adjust their life’s trajectory, goals, and priorities downward to accommodate their impaired cognitive state. Parallel research published by the Journal of the American Medical Association (2015) reveals the nearly 30 percent of marijuana users suffer from Cannabis Use Disorder (CUD). This is much higher than the addiction rate for those who use alcohol. One of the reasons is that the average age on initiation to illicit drugs is during the 12th year. This precedes the neuronal pruning and myelination that occurs during puberty. Out of 8,000 new initiates to an illicit drug each day in the US, 7,000 will use marijuana.

How cannabis use makes achievement so much harder


One person’s experience with marijuana addiction and how it messed up college:

I was at Georgia Tech pursuing my dream of becoming a biomedical engineer. I smoked marijuana for the first time at a Halloween party and by Christmas, I was getting high 3-4 times per week. I squeaked by and passed my first semester exams, but by spring break, I could no longer keep up. The next year I lost my scholarship, became a business major and 2 years later I dropped out. Now I have 30 thousand dollars of debt for my student loans. I wish I never started smoking weed because now I can’t stop. —Devon, 28

It’s just too hard to smoke up 3-4 times per week and remain motivated and disciplined enough to get up early and put in the hard work necessary to succeed in something difficult. Consequently, marijuana users are frequently unemployed or underemployed in jobs that are less challenging. Unfortunately, it isn’t until they quit using cannabis that they realize how marijuana has robbed them of precious years, and the life or career they truly desired.

Regrettably, the legalization of marijuana in Colorado and a dozen of so other states has sharply increased the prevalence of use and mortality among young people. The results of this shortsighted
thinking will be disastrous. Millions of impaired young minds that will never realize their potential. Such a waste.


Hurd, Y, et al (2014) Trajectory of adolescent cannabis use on addiction vulnerability. Neuropharmacology Vol 76, Part B. January 2014, Pages 416–424

Patton, G.C., et al. (2007) Trajectories of adolescent alcohol and cannabis use into young adulthood.
Addiction, 102(4):607-615.

Dr Drew Edwards is also on the medical staff at Lakeview Health in Jacksonville Florida, as a clinical consultant, clinical educator and researcher.  Dr. Edwards conducts and has published original research on depression and chronic illness. He writes about behavioral health, addiction medicine, obesity, parenting and youth culture and is a forensic expert in the neurobiology of addictive disease.