The rash of elderly deaths helped push the country's overall number of suicides to 33,093 in 2007, a 2.9 percent increase and the second-highest annual tally on record, the National Police Agency said in a yearly report.
Japanese aged 60 and over were the fastest growing age group among suicide cases, jumping by 987 last year to 12,107 deaths, an increase of 8.9 percent from 2006. The age group made up 36.6 percent of all suicides in Japan in 2007.
The number of elderly suicides eclipsed the previous record high of 11,529 in 2003.
Health trouble was listed as the reason in 56 percent of the elderly deaths last year and economic worries were second, figuring in 15 percent of cases, the study said.
"For those aged above 60, economic and health reasons were closely linked. The figure underlined the fact that many old people were financially struggling, which could easily cause poor health," Masahiro Yamada, a sociology professor at Chuo University in Tokyo.
Japan's society is rapidly aging, straining pension and national health care systems and exacerbating a widening income gap in a country that has long considered itself uniquely egalitarian.
The number of Japanese aged 65 or older hit a record high of more than 27 million in 2007, or 21.5 percent of the population, the government reported in May. Those 75 or older accounted for nearly 10 percent.
The second-largest age group in the suicide study were Japanese in their 50s, accounting for 21.3 percent of the total, though the number dropped 2.8 percent in 2007 to 7,046 cases, the police agency said.
Health problems were believed to factor in 44 percent of the total suicides in 2007, followed by economic and household difficulties, which accounted for 22 percent, the survey said. No reason was known in 30 percent of the cases.
Depression alone was believed to cause nearly 20 percent of Japan's suicides last year, it said.
Japan has long battled its stubbornly high suicide rate, the ninth highest in the world. The government has earmarked US$220 million for anti-suicide programs to help those with depression and other mental health problems.
Last year, it also set a goal of cutting the suicide rate by 20 percent in 10 years through steps such as reducing unemployment, boosting workplace counseling and filtering Web sites that promote suicide.
Japan is now in the grip of a new wave of suicides from mixing commonly available chemicals to form deadly hydrogen sulfide gas. Police said 517 people have killed themselves so far this year by inhaling such fumes, the latest in a series of suicides fads in Japan. That far surpasses the 29 hydrogen suicides last year.