Understanding of the nature of major challenges associated with the ageing population is becoming an increasingly critical aspect of modern health care system.
A considerable body of evidence is now available to show that the process of aging is largely due to molecular damage caused by reactive oxygen species, electrophiles, and other reactive endobiotic and xenobiotic metabolites (McEwen et al. 2005). Ageing is associated with the degeneration of functional capacity in all parts of human body, and at all levels of organisation from molecules to complete organ systems. This process is normally referred to as 'senescence' and comprises genetic and external factors (Mera 1992).
Quality of life of elderly patients depends more on ageing-related disease than solely on chronological characteristics. 'Natural' transformations in the status of the organism during the process of ageing, such as the changes in the immune, cardiovascular and endocrine systems (Martin, & Sheaff 2007), occur simultaneously with pathological processes associated, in their turn, with variety of age-related diseases, such as wear and tear of skin, muscles, and skeleton (Freemont, & Hoyland 2007), cardiovascular system (Greenwald 2007), etc. These two types of changes interact closely in various types of age-related diseases such as hearing loss, noise damage, skin damage, hypertension, increased body mass index, etc (Martin, & Sheaff 2007).
At the cellular level the process of ageing is associated with chromosomal, nucleic acid, protein and other changes (Terman et al. 2007). The pathways involved in these changes have been revealed to possess common features with disease processes. This discovery is very essential for it enables the researchers to identify and describe some mechanisms that play the key role in the interaction between which natural and abnormal ageing-related changes. Specifically, the interactions between environment, nutrition, disease and the process of ageing have become the focal point of research intended to reveal the basic mechanisms of the pathogenesis of age-related disorders (Martin, & Sheaff 2007).
Sensory impairments, especially those related to hearing and vision, often substantially limit elder adults' intellectual functioning and ability to interact with their environments (Baltes & Lindenberger, 1997). Many of the illnesses and chronic physical conditions that are common in late adulthood tend to have substantial impacts on particular aspects of cognition, as do many of the medications used to treat them. Accumulation of these factors may produce a noticeable decline that elder adults experience in intellectual functioning, as opposed to the normal process of growing old (APA, 2003). In addition to sensory integrity and physical health, psychological factors such as affective state, sense of control and self-efficacy, coupled with active use of information processing strategies and continued practice of existing mental skills may influence elder adults' level of cognitive performance (APA, 2003).
Over the last two decades, the importance of professional psychological services has been increasingly