NBC News (8/27, Fox) reports on two studies published in JAMA Psychiatry that examine the effect of marijuana on the brain. In the first study, “David Pagliaccio, formerly of Washington University in St. Louis and now at the National Institute of Mental Health, and colleagues” compared the brains of marijuana users to non-users.

The results seemed to suggest that marijuana users “had some shrinkage in two brain regions called the amygdala and the right ventral striatum,” but when researchers compared marijuana users to their siblings, “the differences disappeared.” Meanwhile, a second study “found that marijuana appears to change the brain structure of young men with a high genetic risk of schizophrenia.” Dr. David Goldman, of the National Institute on Alcohol Abuse and Alcoholism, said the studies don’t offer a clear picture of anything, adding, “It’s probably more a story of what we don’t know than what we do know.”

According to HealthDay (8/27, Thompson), Dr. Goldman wrote, “The burden of cannabis’ effects may fall more heavily on people who, because of genetic makeup or early life exposures, are at greatest risk for brain structural changes, psychosis or addiction.” He added “It is safer not to expose people to psychoactive drugs.”

Related Links:

— “Marijuana Doesn’t Shrink Brains, But It Can Change Them, Studies Find,” Maggie Fox, NBC News, August 27, 2015.

Reuters (UK) (8/26, Doyle) reports that a research letter published online Aug. 25 in the Journal of the American Medical Association suggests that US combat veterans who have seen action in Afghanistan and Iraq and who were separated from military service because of misconduct appear to have an increased likelihood of being homeless.

Researchers arrived at this conclusion after analyzing data on some 448,290 separations from the military of active-duty service members who were deployed in Iraq or Afghanistan and went on later to avail themselves of services offered by the Veterans Health Administration. An expert who had no involvement in the study pointed out that mental health disorders may play both a role in why such veterans were discharged for misconduct and why they are homeless.

Related Links:

— “Veterans discharged for misconduct have higher risk of homelessness,” Kathryn Doyle, Reuters, August 25, 2015.

According to the Wall Street Journal (8/26, Kesling, Subscription Publication), a report (pdf) from the Department of Veterans Affairs’ inspector general finds that even after an extensive hiring push, the agency still has an insufficient number of full-time psychiatrists to keep up with demand and current staff is not being used efficiently.

Related Links:

— “Report: VA Falls Short on Mental-Health Care Despite Hiring Push,” Ben Kesling, Wall Street Journal, August 25, 2015.

The AP (8/25) reported that in a report issued Aug. 25, investigators with Alzheimer’s Disease International “say there are now nearly 47 million people living with dementia globally, up from 35 million in 2009.” Those experts “warned that without a medical breakthrough, numbers will likely double every 20 years.”

According to TIME (8/25, Basu), the report also revealed that “58% of all people with dementia reside in developing countries.” In addition, by mid-century, “68% of those with dementia will be located in low and middle income countries, where services are limited and populations are aging quickly.”

Related Links:

— “Report: Nearly 47 million people now have dementia,” Chron, August 27, 2015.

The Washington Post (8/26, Sun) “To Your Health” blog reports that taking omega-3 supplements does not “slow cognitive decline,” according to a study published in the Journal of the American Medical Association. The study enrolled 4,000 older participants “who were at risk for developing age-related macular degeneration” in order to investigate the possible cognitive benefits of omega-3 supplements. National Eye Institute Deputy Clinical Director Elizabeth Chew and her team found that consuming these supplements had “no statistically significant effect on cognitive function.” Chew concluded, “The supplements just don’t cut it,” adding, “If people are thinking [taking them] is going to help cognitive function, it’s not going to do so among the older age group.”

Related Links:

— “Omega 3 is still good for the brain. But ‘fish oil supplements just don’t cut it.’,” Lena H. Sun, Washington Post, August 25, 2015.