Mohammed T. Abou-Saleh

88 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRYthe older population and are not fully compensated for by youths.Thus, the proportion of older persons in the total population isexpected to steadily increase, reaching nearly 23% in 2030. Thisaggregate figure masks considerable variation among countries,with Japan (27.3%), and Italy (29.1%) expected to reveal thehighest levels and Ireland (17.9%) and New Zealand (18.8%) atthe lower end. Nonetheless, the proportion of older persons for allcountries in the region is historically unprecedented. An addeddimension of these changes in the age composition of thepopulations is the expectation that by 2015 the proportion ofolder persons will exceed the proportion of young persons aged0–14 years, given realization of the assumptions regarding fertilityintroduced into the projections.AGE AND SEX COMPOSITIONS OF THE AGEDPOPULATIONNot only has the region experienced overall population aging, butthe older population has itself aged. The growth of the oldest old(persons aged 80 and over) has important implications in terms ofthe health status of this group of people and their need for healthcare and social supports. If the assumption is correct that theprevalence of mental health problems increases with age, thenthese trends toward aging of the older population take on addedimportance. Moreover, the incidence of the most severe mentaldisorders (e.g. senile dementia of the Alzheimer’s type) is greatlymanifested at advanced ages 3 . The percentage of oldest old in thetotal older population showed a marked rise in the 1980s, when itincreased from 17% to 22%. It will steadily rise until the year2010 (26%) and then will decline slightly to 24% in 2025. Thedecline reflects the large number of persons who will reach theolder ages between 2010 and 2030. Nonetheless, the overallnumbers of oldest old will nearly double to 72 million in theregion over the 2000 figure.A noteworthy feature of the older population in the region isthe preponderance of women over men. In 2000, there were 153older women for every 100 men and, among the oldest old, 226women for every 100 men. These levels for both groups are likelyto be somewhat attenuated in the future, as the aged populationgains large new cohorts, but the imbalance will still remain.COMPONENTS OF POPULATION AGINGWhile the overall age and sex structure of a population is affectedby fertility, mortality and migration, the main factors producingchanges in the older population result from the relative size ofcohorts reaching the older ages and the survival of these olderpersons to further advanced ages. Although the major source offuture growth results from the large baby boom birth cohorts thatwill enter the older population, as was noted previously, theimproved chances of persons reaching old age and surviving toadvanced ages have also been a potent force in producing thepresent and future growth 4 .The average life expectancy of a baby born between 1995 and2000 and experiencing the age-specific mortality conditions of thatperiod was 71.1 years for a boy and 78.7 for a girl 5 . To gain someperspective on these figures, the following levels were estimatedfor the period 1970–1975 and projected for future periods:Male Female1970–1975 67.6 74.72020–2025 75.5 81.82045–2050 78.2 84.2There was an increase of 3.5 years for males and 4.0 for femalesin the 25-year period preceding 1995–2000 and gains of 4.4 and3.1, respectively, projected for a similar time period to 2020–2025.The reversal in the projected survival by gender can be noted andthis is carried over into the next period, when only minor lifeexpectancy gains are forecasted. Aside from this questionablegender reversal, some also view the assumptions underlying theUN projections as rather conservative. In fact, a life expectancy atbirth for females of over 84 years has already been attained inJapan and is likely to be exceeded in many other countries by thesecond decade of the twenty-first century.The extension of life has meant that the remaining years of lifeafter persons reach age 65 have increased markedly. For the USA,a surviving male could expect to live 15.7 years on average at age65 in 1996 compared with 11.5 in 1900, a 36% increase 6 . Theaverage female could expect to live an additional 19 years in 1996,a gain of 6.8 years or 55%. Moreover, 76% of men and 86% ofwomen born in 1996 can expect to reach age 65, doubling thepercentages in 1900.Thus, not only have more persons reached oldage, but an increasing amount of one’s life is being spent as anolder person.These improvements in survival have resulted from widespreadreductions in communicable diseases and even declines in thelethal progressions of some of the predominant chronic, degenerativediseases. A noteworthy feature of overall mortality trendsin the region has been the reductions in death rates at older ages.An emerging issue of considerable policy importance is the extentto which these improvements in longevity have been accompaniedby increases in active life expectancy free of major chronicdiseases, functional disabilities and institutionalization. Whiledata are lacking to definitively establish past developments, thereis evidence that active life expectancy has tended to increase,perhaps even keeping pace with improvements in overall lifeexpectancy 7 . However, with increased population aging, the netresult of these developments is the likelihood of increasednumbers of persons at old ages with chronic co-morbidities anddisabilities and, therefore, in need of long-term care andrehabilitative services.SUPPORT STRUCTURESThe demographic parameters that relate most directly to theseemerging issues concern the households and family conditions ofolder persons who are likely to need supportive assistance (carereceivers)and those who are potential care-providers. A numberof complex demographic and social factors are involved in thismatrix.There has been a steady trend over time toward increasedproportions of older persons being married and reduced proportionsbeing single and widowed in the countries of this region 8 .Moreover, this development is true not only for the total agedpopulation, but also for all age groups up to the most advanced.However, it should be noted that a much larger proportion of menthan women are likely to be married, with the converse true ofwidowhood. These trends are a product of both the previousmarital experience of persons in cohorts reaching the older agesand improvements in the joint survival of spouses. Nonetheless,there are strong signs that this pattern will change in the nextcentury, as large cohorts of persons who are divorced or havenever married enter into the older ages.Another distinctive trend has been the increasing likelihood ofolder persons, both married couples and individuals, to liveindependently from other family members or non-relatives. Thispattern of living arrangements reflects the smaller size of familiesresulting from prior declining fertility, as well as value preferencesamong older persons for independent living. However, theseobservations say little about the degree of contact among family