Previous research indicating that marijuana use is associated with depression and anxiety is being challenged by a new study that claims the opposite — that using marijuana as an adult has no correlation with the mood and anxiety orders it is typically associated with.

According to the Washington Post, a new study published Wednesday in the journal JAMA Psychiatry found that using marijuana does not cause depression or anxiety.

Researchers took a look at the records of 35,000 U.S. adults who participated in the National Epidemiological Survey on Alcohol and Related Conditions, which studied marijuana use in 2001 and 2002. In 2004 and 2005, the mental health of these participants was examined.

The study accounted for factors which might complicate the issue, looking for things like family history and possible past psychiatric disorders. Once these were considered with the data, the study concluded that “cannabis use was not associated with increased risk for developing mood or anxiety disorders.”

What marijuana use is linked with, however, is further substance-use disorders. The research indicates that adult marijuana use can lead to use of and dependence on alcohol, tobacco, marijuana and other drugs.

“The findings concerning cannabis raise the question of whether alcohol use also contributes to the risk of subsequent substance use disorders,” said the study’s lead author Mark Olfson of Columbia University. He concluded, however, that such a question is beyond the scope of the current study.

Critic Keith Humphreys, an addiction and mental-health specialist at Stanford University, notes that the study does not address a previously observed link between heavy marijuana usage and schizophrenia. He added that that connection might also be as spotty as the one linking marijuana to depression.

“I don’t know if we will ever know because it’s hard to predict rare events, and schizophrenia is rare,” he said.

Scientists have discovered a new type of cancer treatment which targets and attacks tumor cells — and then waits in the body to destroy any more that might pop-up in the future.

According to BBC News, a presentation at the annual meeting of the American Association for the Advancement of Science (AAAS) came with claims that a new cancer treatment has been discovered which stops cancer from ever coming back.

This new type of therapy, called T-cell therapy, uses the bodies own immune cells to attack tumor cells that have spread throughout the body, working like a vaccine.

“In the laboratory and in clinical trials, we are seeing dramatic responses in patients with tumors that are resistant to conventional high-dose chemotherapy,” said Dr. Stanley Riddell, who presented the treatment at the AAAS meeting.

Like a vaccine, T-cell therapy tells the body’s own immune system to find and destroy cancer cells. Should it ever find any of those cells again, they will be destroyed as well.

White blood cells are removed from a patient and genetically engineered to remember to attack tumor cells. Millions of white blood cells are modified and put back in the patient — with the ability to kill tumor cells.

The scientists behind the new procedure are working to improve the technology by reducing potential side effects and having the ability to target a wider range of cancers.

During clinical trials, patients found that even 14 years after receiving the treatment, the T-cells were still present within them. After results like this, scientists are hoping that this type of immunotherapy will someday replace cell-damaging chemotherapy.

A link between cancer and exposure to artificial turf is being examined after years of unease and suspicion about a possible correlation.

According to Forbes, in 2014 an NBC began to give more exposure to the potential link during a broadcast focusing on Amy Griffin, associate head coach for the University of Washington’s women’s soccer team.

That broadcast included interviews with Griffin, where she described what she dubbed “a stream of kids” playing soccer on artificial turf and soon after being diagnosed with cancer. Griffin has compiled a list of 38 American soccer players who have been diagnosed with cancer — 34 of them goalies.

Among these players, blood cancers like lymphoma and leukemia were most common.

A USA Today report in March of last year claimed that “lead levels high enough to potentially harm children have been found in artificial turf used at thousands of schools, playgrounds and day-care centers across the country, yet two federal agencies continue to promote the surfacing as safe.”

The issue began to become further complicated when NBC followed up their Amy Griffin broadcast with another that claimed the federal government has remained largely silent on the issue. Additionally, this new report claimed that the EPA failed to answer direct on-camera questions about the safety of artificial turf for children.

Following up the report, Congress gave the EPA a November 6th, 2015 deadline to look further into potential links between artificial turf and cancer. The EPA failed to meet this deadline.

Now, Reuters is reporting that three U.S. government agencies will be teaming up to study any link between turf and cancer. The Environmental Protection Agency, the Consumer Product Safety Commission and the Centers for Disease Control and Prevention will be in charge of studying the issue.