Previous studies showed that depression, the most prevalent psychiatric disorder worldwide, is linked to areas of the brain shrinking in size.

But when it is paired with anxiety, the second most widespread psychiatric disorder according to the World Health Organization, one area of the brain becomes "significantly" larger.

Many people suffer from both depression and anxiety, yet most of the past studies do not account for patients with both conditions.

A new study, published by Australian National University (ANU) researchers found that over time the pairing has a profound effect on brain areas associated with memory and emotional processing.

The study looked at the brains of more than 10,000 people to find the effects of depression and anxiety on brain volume.

The study shows that depression alone causes the hippocampus, the part of the brain linked to memory and learning, to shrink. In contrast, when depression and anxiety occur together it leads to an increase in size of the part of the brain linked to emotions, the amygdala.

"We found people who have depression alone have lower brain volumes in many areas of the brain, and in particular the hippocampus”, said the study lead and Ph.D. researcher Ms Daniela Espinoza Oyarce.

"Anxiety lowers the effect of depression on brain volume sizes by 3 percent on average - somewhat hiding the true shrinking effects of depression," she said.

“This becomes even more relevant later in life because a smaller hippocampus is a risk factor for Alzheimer's disease and may accelerate the development of dementia."

Over the years, neuroscientists have continued digging into the relationship between the brain and mental illness to offer hope to the sufferers. According to leading mental wellbeing support organization Beyond Blue in any one year around a million Australian adults have depression and more than 2 million have anxiety.

Ms Espinoza Oyarce emphasized on the need for future studies. "More research is needed into how anxiety lowers the effects of depression, but for the amygdala, perhaps anxiety leads to overactivity."

A new study says US communities that made using face masks in public compulsory saw a decline in the spread of coronavirus.

After five days of mask mandates, the daily coronavirus growth rate slowed by just under 1 percent, while after 21 days, it slowed by about 2 percent, according to the study, reports Xinhua.

Researchers from the Department of Health Management and Policy at the University of Iowa College of Public Health reported the study result in the journal Health Affairs.

Between April 8 and May 15, governors of 15 US states and the mayor of Washington, DC signed orders to place mask mandates in public. The researchers studied changes in the daily county-level COVID-19 growth rates between March 31 and May 22.

They also projected the number of averted COVID-19 cases with the mandates for face mask use in public by comparing actual cumulative daily cases with daily cases predicted by a model if none of the states had enacted the public face cover mandate at the time they did.

Read Also: No ‘silver bullet’ to combat Covid-19 pandemic: WHO chief

The model estimates suggested that 230,000-450,000 cases may have been averted by May 22 due to these mandates.

The US is currently the worst coronavirus affected country in the world with 4,717,568 confirmed cases and 155,469 deaths.

Coronavirus cases were first reported in China in December last year. The World Health Organization declared it a pandemic in March.

The race for developing a vaccine is on but it is unclear when it will be available. Health experts suggest maintaining personal hygiene, washing hands regularly with soap and running water or alcohol based substance, wearing masks in public and maintaining physical distance from others as measures to curb the virus’ spread.

Aiming to lower the incidence of liver cancer among patients with hepatitis B, China has launched a research project on Tuesday, marking the World Hepatitis Day.

It was sponsored by the Chinese Foundation for Hepatitis Prevention and Control, reports Xinhua

It will observe and study the five-year incidence of liver cancer among 20,000 chronic hepatitis B patients in 99 hospitals across the country.

It aims to optimise the clinical treatment path of hepatitis B antiviral therapy and explore ways of reducing the incidence of liver cancer linked to hepatitis B.

Zhang Wenhong, a leading expert working on the project, said that they hope long-term treatment and observation can answer questions that traditional clinical trials cannot, like what's the difference in liver cancer incidence between different therapies.

According to data from 2019, primary liver cancer is the fourth most common malignant tumor and the second leading cause of death among all kinds of tumors in China.

It is estimated that 85 percent of China's liver cancer patients have been infected with the hepatitis B virus.

Scientists found an experimental blood test highly accurate at distinguishing people with Alzheimer’s disease from those without it in several studies.

It is boosting hopes that there soon may be a simple way to help diagnose this most common form of dementia.

Developing such a test has been a long-sought goal, and scientists warn that the new approach still needs more validation and is not yet ready for wide use. But Tuesday’s results suggest they’re on the right track.

The testing identified people with Alzheimer’s vs. no dementia or other types of it with accuracy ranging from 89% to 98%.

“That’s pretty good. We’ve never seen that” much precision in previous efforts, said Maria Carrillo, the Alzheimer’s Association’s chief science officer.

Dr. Eliezer Masliah, neuroscience chief at the U.S. National Institute on Aging, agreed.

“The data looks very encouraging,” he said. The new testing “appears to be even more sensitive and more reliable” than earlier methods, but it needs to be tried in larger, more diverse populations, he said.

The institute had no role in these studies but financed earlier, basic research toward blood test development.

Results were discussed at the Alzheimer’s Association International Conference taking place online because of the coronavirus pandemic. Some results also were published in the Journal of the American Medical Association.

More than 5 million people in the United States and many more worldwide have Alzheimer’s. Current drugs only temporarily ease symptoms and do not slow mental decline.

The disease is usually diagnosed through tests of memory and thinking skills, but that’s very imprecise and usually involves a referral to a neurologist. More reliable methods such as spinal fluid tests and brain scans are invasive or expensive, so a simple blood test that could be done in a family doctor's office would be a big advance.

Last year, scientists reported encouraging results from experimental blood tests that measure abnormal versions of amyloid, one of two proteins that build up and damage Alzheimer’s patients’ brains. The new work focuses on the other protein — tau — and finds that one form of it called p-tau217 is a more reliable indicator. Several companies and universities have developed experimental p-tau217 tests.

Dr. Oskar Hansson of Lund University in Sweden led a study of Eli Lilly’s test on more than 1,400 people already enrolled in dementia studies in Sweden, Arizona and Colombia. They included people with no impairment, mild impairment, Alzheimer’s and other neurological diseases.

Scientists at the University of California, San Francisco, found it helped distinguish people with Alzheimer’s from those with another neurological disease — frontotemporal lobar degeneration — with 96% accuracy in a study of 617 people.

Dr. Suzanne Schindler of Washington University in St. Louis, Missouri, also found p-tau217 better than some other indicators for revealing which patients had plaques in the brain — the hallmark of Alzheimer’s.

“When patients come to me with changes in their memory and thinking, one of the major questions is, what’s the cause? Is it Alzheimer’s disease or is it something else?” she said. If tau testing bears out, “it would help us diagnose people earlier and more accurately.”

Schindler has already launched a larger study in a diverse population in St. Louis. Researchers have done the same in Sweden.

If benefits are confirmed, Masliah, Carrillo and others say they hope a commercial test would be ready for wide use in about two years.

Scientists don’t know for sure yet whether there is any chance of getting infected with COVID-19 twice.

But they believe it is unlikely.

Health experts think people who had COVID-19 will have some immunity against a repeat infection, reports AP.

But they don’t know how much protection or how long it would last.

There have been reports of people testing positive for the virus weeks after they were believed to have recovered, leading some to think they may have been reinfected

More likely, experts say people were suffering from the same illness or the tests detected remnants of the original infection.

There’s also the chance tests could have been false positives.

Scientists say there has been no documented instance of a patient spreading the virus to others after retesting positive.

With similar viruses, studies have shown that people could fall sick again three months to a year after their first infections.

 It’s still too early to know whether that’s also possible with the coronavirus.

“It’s very much emerging science,” said Dr. Philip Landrigan, director of the global public health program at Boston College.

A small US study published last week also found the antibodies that fight the coronavirus may only last a few months in people with mild illness, suggesting people could become susceptible again.

But antibodies aren’t the only defense against a virus, and the other parts of the immune system could also help provide protection.

Settling the question of whether reinfection is possible is important. If it can occur, that could undermine the idea of “immunity passports” for returning back to workplaces.

And it would not bode well for hopes of getting a long-lasting vaccine.