People in less-affected areas of southwest China's earthquake zone have been "neglected for half a year" since the fatal earthquake in May, according to counselors in the region.

"The percentage of people with psychological problems was higher in less-affected areas, such as Chengdu," said psychologist Zhang Wei, deputy director of the West China Medical School of Sichuan University.

Zhang and his team interviewed more than 20,000 people in four cities of Sichuan Province, including the provincial capital Chengdu. They found that overall, those with post-traumatic stress disorder (PTSD), an anxiety disorder that can follow disturbing events, had fallen below 10 percent. But the figure in less-hit areas was somewhat above the average.

"It is unusual," Zhang said. However, "people in areas farther away from the epicenter have been neglected."

Zhang's team noted that people in less-hit zones might have lost their families, been overworked or been affected by media reports on the disaster.

According to the study, more than 5 percent of Sichuan's population had PTSD, equivalent to 2 million people. Such a state of anxiety might lead to heart or digestive ailments, injuries or even death.

About 80 percent could be helped by psycho-social intervention, but the other 400,000 people would have PTSD forever, the study said.

Zhang said that at the six-month mark, there had been a second wave of PTSD. Many people were "trapped" in the memory of trying to save themselves or others, which caused depression, Zhang said.