Since we developed the new neuropsychological test batteries to diagnose the early dementia 20 years ago, we have accumulated the data of the regional investigation on the incidence of dementia and their severity covering almost all Japan. In most towns and villages, the whole incidence of dementia was from 25% to 30% to those of more than 65 years old, of which the ratio of the mild, the moderate and the severe dementia were mostly 2 to 2 to 1. In our criteria, the patients of the mild dementia has solely the disturbance of the highest brain function or the prefrontal function ; therefore they can not manage the social business because they have the trouble in wit, imagination, planning or attention distribution and so on. On the tests, they fail only on the prefrontal function tests, for example on Kana pick-out test. Those of the moderate dementia have the trouble even in house-keeping jobs ; cooking, cleaning or washing. On the tests, they also fail on the prefrontal function tests and get MMS from 23 to 15 points. Those of severe dementia have the difficulty to take self-care. They get MMS of less than 14 points. Once advanced into this level the recovery becomes almost impossible. As for the cause of dementia, more than 90% of the whole dementia was thought to be derived from the bad life habbits (circumferential). They are characteristically workaholic without any hobby or any favorite arts since young. Soon after the retirement they become tedious and loose volition and interest for anything.The dementia starts 2-3 years thereafter. We called this type as the dementia of senility and disuse atrophy (DSD). The vascular dementia accounted 5% at most by the several examinations in details. The Alzheimer disease of the genetic mutation accounted for only 1.2% which showed the early onset in 40th or 50th of age and became ill in bed within 2 or 3 years. This type was resistent for any treatment, even for the brain rehabilitation. As the treatment for the type of DSD, we made diagnosis as early as possible, at least in the level of mild or moderate and gave them the brain activation therapy or the brain rehabilitation using several games, music, painting and sports. As the results, it was confirmed that about 60% of them could come back to the level of independent home life and other 35% was not worsened. The effect could be continued more than 6 or 7 years.
We performed a statistical analysis to find characteristic elements or moments which may make old people feel life worth living in rural areas in Japan, using the results of a questionnaire survey we reported in 1996 wiht the title “Aging of the Rural Population and Effective Measures to Respond to the Trend.” In the analytical procedure, we used a multiple regression analysis with a logistic model. The dependent variable was the question “Is your present life worth your while to live?” As the independent variables, 168 questions were used covering various aspects of everyday life-farm work, activity in the community, environment, health, medication, aging, death, etc. The number of subjects responded to the survey totaled 1, 373 men and women at age 55 and over living in 7 prefectures in Japan. The purpose of the analysis was to obtain items of questions with statistically significant coefficients in the logistic regression equation for the dependent variable. A total of 28 items of questions of statistic significance were obtained and most of the answers to these questions had a positively directed nature in order. Some of the items are as follows: “Principles in life, ”“High hopes on agriculture, ”“Family with plural generations, ”“Satisfaction with domestic conditions, ”“Positive (healthy) ADL-markers, ”“Liking for harmony, ”“Participation in neighborhood activity, ”“Medication up to the terminal stage, ”“Willingness to leave one's body to medicine or donate for organ transplantation, ” etc. Further, we discussed the comparison of items of unique characteristics between prefectures, healthy and unhealthy groups, sexes, age groups, and farmers and non-farmers.