In the U.S., marijuana use is fairly common among teenagers and young adults in the typical college age range of 18 to 25. Unfortunately, intake of the drug is associated with a number of significant problems, including memory and concentration deficits, altered brain development and the onset of cannabis use disorder (cannabis abuse and\/or cannabis addiction). In a study published in July 2014 in the Journal of Studies on Alcohol and Drugs, researchers from Canada\u2019s University of Victoria used a long-term study of marijuana use in teens and young adults between the ages of 15 and 25 to determine if use of the drug reduces the odds that a young person will enter college or some other post high school academic program. In the overall U.S. population of preteens, teens and adults, marijuana is third in popularity only to alcohol and cigarettes\/nicotine as a recreational substance. Young people between the ages of 18 and 25 use all forms of illicit\/illegal drugs with greater frequency than people in any other age group, and this fact holds true for marijuana intake. While just 7.3 percent of the total population uses the drug on at least a monthly basis, 18.7 percent of people in this college age range use marijuana at least that often. Children between the ages of 12 and 17 have a rate of marijuana intake roughly equal to the average for the whole population. Boys in this age range have a slightly higher rate of use (7.5 percent) than girls (7 percent). Interestingly, among all people age 18 and older, the rate of intake for marijuana and all other illegal\/illicit substances is highest among people who never graduated from high school and lowest among people who graduated from college. Brain Effects of Marijuana\/Cannabis In any preteen, teen or adult user, marijuana can trigger problems with memory formation, memory retention, mental clarity, learning skills, the ability to solve problems and the ability to focus or concentrate. However, the possible brain-related consequences of using the drug are much starker in preteens, teenagers and younger adults who have not yet completed the normal process of brain development. In these individuals, heavy marijuana intake can lead to substantial disruption of the development process and may lead to permanent deficits in higher-level mental function that include a declining IQ score. Even occasional preteen and teen marijuana users have elevated risks for the onset of cannabis use disorder. Impact on College Attendance In the study published in the Journal of Studies on Alcohol and Drugs, the University of Victoria researchers used information from a long-term project called the Victoria Healthy Youth Survey to assess the impact of marijuana use on the odds that a college-age young adult will attend college or seek other educational opportunities after high school. This survey collected information every two years between 2003 and 2011. The researchers gathered data from 632 survey enrollees and used this data to identify patterns of marijuana use between the ages of 15 and 25. All told, three patterns of use emerged: lack of involvement in marijuana intake (31 percent of study participants), occasional involvement in marijuana intake (44 percent of the participants) and frequent involvement in marijuana use (25 percent of the study participants). In addition to relative involvement in marijuana use, the researchers looked at factors that included each participant\u2019s grades in high school, relative level of behavioral problems, family background and gender. After completing an analysis of these factors, they concluded that those individuals who used marijuana frequently were significantly more likely to have behavioral problems and do poorly in high school; these individuals also had the lowest odds of attending college or otherwise extending their education beyond high school. Conversely, the study participants who did not use marijuana had a low level of involvement in behavioral problems, did relatively well in school and had the highest odds of continuing their education past high school. The occasional users also got fairly good grades, mostly avoided behavioral problems and commonly took part in post high school educational opportunities. However, they typically took longer to begin their post high school educations and were also substantially less likely to complete the course of education they began. The study\u2019s authors concluded that regular use of marijuana before and during the typical age for college attendance may make it significantly less probable that a young person will pursue education beyond high school. They also concluded that occasional use of the drug may meaningfully decrease the chances for success in post-college education.