A new study reveals the impact of marijuana on teenagers. This JAMA Psychiatry study analyzed 69 different studies on young cannabis users in the hope of establishing overall patterns and more concrete conclusions to inform the continuing changes in marijuana laws. Overall, young people who were frequent marijuana users showed lower scores for memory, learning and retaining new information, and higher-level problem-solving. However, the shocking part was that while there are biological factors that would suggest marijuana would affect the brain long-term, all of the most credible studies on young users indicated that those negative effects on brain function actually went away after three or more days of abstinence. The most frustrating part for marijuana researchers is the near impossibility of proving causality, and this group was only looking at information on recreational users, not medical users, but this newest indication that marijuana only has short-term negative brain effects is encouraging to those hoping to expand its credibility for medical use. 

Even a small amount of exercise can significantly decrease your chance of developing Alzheimer’s. There has been an influx of research linking exercise to brain health, but a recent study conducted in Sweden (on 191 women over 44 years) suggests that being just “moderately fit” made women a lot less likely to develop dementia later on than the women who could barely exercise at all. The fittest women participating were 90 percent less likely to develop the disease than those who could not complete any fitness test. Though they could not show cause and effect, the findings indicate that improving fitness levels at middle age has hugely positive effects on mental health later. Best of all, that means that middle age is not too late to start in order to make a difference. Laura Baker of Wake Forest University conducts similar research and says that moderate exercise is if “you can hear yourself breathing and you are starting to sweat and your heart rate is just getting up.” You do not have to be at athlete-level training – just become active enough to fit those criteria each day. The research shows that exercise has had a far greater impact on positive memory and cognitive function than any existing medicine.