Health and Social Care Secretary Jeremy Hunt has announced that the UK will host the first ever Global Ministerial Mental Health Summit(峰会) in London this October.This global summit aims to put mental-health care on an equal footing with the physical kind.

But there is a long way to go. One in four people will experience a mental-health problem at some point in life. In rich countries mental illnesses account for more suffering and premature death than heart disease, strokes(中风) or cancer. Meanwhile the central-African countries have just one mental-health professional per 100,000 people, a fiftieth as many as Europe has. (Less than 1% of foreign aid for health care goes towards mental health.)

As developing countries handle infectious diseases, mental health will consume a greater share of budgets and attention there. By 2020 mental-health conditions may account for 15% of the global burden of disease, but even in rich countries many people with common problems still go without treatment.

It is clear that mental illness is fast becoming one of the global health challenges of the 21st century. Until recently, this hasn’t had the profile it deserves on a global stage. The ministers gathering in London must produce new money and focus—and not just another declaration. The summit is also expected to help countries learn from each other to find the best ways to deal with increased rates of depression and anxiety among young people.

Older adults who sleep six hours or fewer a night may have elevated risk for dementia(痴呆症) and other cognitive (认知的) issues, a new study finds.

Researchers at Stanford University measured seniors' (ages 65 to 85) dementia risk and cognitive abilities, finding higher risk in those patients who regularly slept six or fewer hours compared to those who slept seven or eight hours. Those seniors who slept nine or more hours also had lower cognitive functions and other health issues, but the researchers didn't find the same high dementia risk in this group.

The findings demonstrate how important it is for adults to maintain a healthy sleep cycle, especially as they get older.

As adults age, it's common for their sleep patterns to change or become disrupted — leading to longer, shorter, or more irregular sleep. This disruption may be linked to Alzheimer's and other forms of dementia, impacting seniors' ability to remember information, problem-solve, and go through everyday behaviors. Sleep disruption can also be caused by or heighten depression, cardiovascular disease（冠心病）, and other conditions.

A recommended sleep time for seniors is seven to eight hours, the researchers said. Six or fewer hours corresponded to short sleep, while nine or more hours corresponded to long sleep.

The Stanford researchers measured levels of beta amyloid, a protein in the brain that is typically found in high levels when a patient develops Alzheimer's. In addition, the researchers used several tests for memory, attention, spatial skills, and executive function to identify patients' cognitive abilities. Those patients sleeping for six hours or fewer a night were more likely to develop dementia, the researchers found. The low-sleep patients   had higher levels of beta amyloid.

The Stanford researchers found that patients with lower sleep also performed worse on memory tests, while those with higher sleep (more hours) performed worse on executive function tests，which measure the brain's ability to switch between different tasks.

―The main takeaway is that it is important to maintain healthy sleep late in life, Winer told CNN.

Ebola is a dangerous virus that can cause people to get very sick and even die. The virus is causing the biggest problems in western Africa, where it has spread quickly. 【小题1】But it can get worse and cause life-threatening symptoms, such as bleeding and trouble breathing.

Ebola does not spread like colds or the flu because it does not float through the air. Ebola also doesn’t spread through food or water, like some other viruses. Instead, Ebola spreads when someone touches the body fluids(液体) of a sick person.

【小题3】

An outbreak is when many people are getting sick with the same illness around the same time. You may have heard of a flu outbreak, which is when lots of people get sick from the same types of flu virus. When an outbreak happens because of a virus, more people could get sick because there is a lot of that virus around.

Where did Ebola come from?

Scientists aren’t sure how the first person gets Ebola at the start. 【小题4】 Tropical animals in Africa believed to carry the virus include great apes, chimpanzees, gorillas, monkeys, fruit bats, porcupines, and forest antelopes.

What do kids need to do about Ebola?

Ebola is making many people sick in Africa, but no matter where you live, it’s always a good idea to wash your hands well and often. 【小题5】