Recent research sheds new light on the effects of cannabis on the brain. It reveals a complex pattern of potential harms and benefits that varies with age and disease.
The findings came from a number of studies that featured at the 2018 annual meeting of the Society for Neuroscience, held in San Diego, CA.
They reveal, for instance, that exposure to marijuana before birth and during teen years can affect the developing brain in several ways.
A scientific study finds that close to half of residential fraternity members had symptoms of alcohol use disorder (AUD) by age 35, and that living in a fraternity or sorority at college is associated with continued binge drinking and marijuana use through early midlife. The research, from the University of Michigan, is published in the Journal of Adolescent Health and was funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health.
The authors analyzed samples of U.S. high school seniors from the Monitoring the Future study who were followed via self-administered surveys up to age 35. The scientists found that males who lived for at least one semester in a fraternity house had significantly higher rates of binge drinking during and after college up through age 35, compared to their peers in college not involved in fraternities, and to non-students of the same age. Among males at age 35, 45 percent of the residential fraternity members reported two or more AUD symptoms, compared to 32.7 percent of non-residential fraternity members, 30.4 percent of college students who were not involved in fraternities and 33.1 percent of their non-college peers. Similarly, women who were residents of a sorority had higher odds of two or more AUD symptoms at age 35 (26.4 percent) when compared to non-residential sorority members (19.1 percent), college students not involved in sororities (18.0 percent) or their non-college peers (16.9 percent).
It’s a well-known fact that many young people use cannabis, and studies have pointed to a link between the drug and psychiatric conditions such as schizophrenia. However, the links between cannabis use and the development of bipolar symptoms over time have been insufficiently studied — until now.
A new study fills this research gap by examining how cannabis use among teenagers is linked with hypomania in early adulthood.
The research was led by Dr. Steven Marwaha, a clinical academic psychiatrist from the University of Warwick in the United Kingdom, and the findings were published in the journal Schizophrenia Bulletin.
Marijuana use is associated with cognitive dysfunction in people with HIV infection who have an alcohol or other drug use disorder, according to a new study from researchers at Boston University School of Public Health (BUSPH), Boston University School of Medicine (BUSM), and Boston Medical Center (BMC).
While researchers did not detect effects of lifetime cumulative exposure, the study, published in Substance Abuse, showed that more frequent current marijuana use was associated with a measure of cognitive dysfunction on the Medical Outcomes Study HIV Health Survey cognitive function scale.
“People with HIV infection have many reasons to have cognitive dysfunction, from the virus itself to medications for HIV infection and related conditions, particularly as they age,” said co-author Richard Saitz, professor and chair of community health sciences at BUSPH, who served as principal investigator on the study. “They also have symptoms like chronic pain and mental health symptoms, and use of marijuana, medically or recreationally, may seem like an option to consider. But at least among people with substance use disorders, it appears to have detrimental effects on cognitive function.”
Researchers at Western University have found a way to use pharmaceuticals to reverse the negative psychiatric effects of THC, the psychoactive chemical found in marijuana. Chronic adolescent marijuana use has previously been linked to the development of psychiatric diseases, such as schizophrenia, in adulthood. But until now, researchers were unsure of what exactly was happening in the brain to cause this to occur.
“What is important about this study is that not only have we identified a specific mechanism in the prefrontal cortex for some of the mental health risks associated with adolescent marijuana use, but we have also identified a mechanism to reverse those risks,” said Steven Laviolette, professor at Western’s Schulich School of Medicine & Dentistry.