**1. Introduction**

The prevalence of chronic medical and psychiatric diseases has continued to increase worldwide, and their consequences have remained a growing concern.

Acting with a number of sociodemographic and clinical variables, they tend to negatively affect life expectancy through, among many other pathways, reducing quality of life. Despite healthcare improvements, there has been little evidence of benefit on life expectancy in people with chronic medical and mental disorders [1–3].

It is equally important to note that baseline adverse psychosocial factors or psychological distress have been implicated as predictors of schizophrenia, hypertension and diabetes, or HIV infection [9–12, 43], through impairment of judgment in the later [24–26]. Also, certain environmental as well as socioeconomic factors have been identified to predispose to tuberculosis like living in an overcrowded

*Impact of Chronic Medical and Neuropsychiatric Illnesses on Quality of Life and Life…*

Studies have indicated that life expectancy decreases with each additional chronic condition [1–3]. A study remarked that a 67-year-old person will live on average 22.6 additional years in the absence of any chronic conditions while a 67-year-old person will live 7.7 fewer years and 17.6 fewer years with 5 chronic conditions and ≥10 chronic conditions, respectively [44]. The same study found that the average marginal decline in life expectancy was 1.8 years with each additional chronic condition ranging from 0.4 fewer years with the first condition to 2.6 fewer years with the sixth condition. These results are consistent by sex and

Another study using a sample of Medicare beneficiaries enrolled as of January 2008, of 21 different chronic conditions and about 1.4 million persons aged 67 and above, found that, on average, a 75-year-old American woman who has no chronic conditions will live 17.3 additional years to more than 92 years old [45]. Conversely, similar individual with five chronic conditions will live, on average, only to age 87, while an individual with 10 or more chronic conditions will survive only to age 80 [45]. Women tend to live longer than men, while white people live longer than black. Clearly, the nature and number of the

chronic diseases are important for life expectancy. An individual with heart disease at age 67 is estimated to live an additional 21.2 years on average, while someone of the same age diagnosed with Alzheimer's disease is only expected to live 12 additional years [46]. Different medical conditions have different life expectancy, but this difference gradually decreases with age and more comorbid conditions

Struggling with multiple chronic illnesses shortens life expectancy dramatically [45–49], and for older individuals, chronic or multiple chronic conditions equally threaten to reverse recent gains in average life spans. The medical advances and new technologies that have allowed sick people to live longer may not be able to keep up with the growing burden of chronic diseases. It is becoming very clear that preventing the development of additional chronic conditions and giving adequate treatment when they occur in the middle ages and the elderly could be the only way to continue to improve life expectancy. Violence and adverse childhood events are said to speed up aging, and life span continues to increase with each

Concerns about premature mortality among people with chronic mental and medical disorders have been increasing [1–3]. Higher general and specific causes of mortality in all or specific age groups have been identified for people with serious medical and mental illnesses [18–21]. People with chronic and severe mental illness have lower life expectancies of between 13 and more than 30 years than the general population [50], and a loss of 8.8 life years (14.1 years for men and 5.7 years for women) was estimated by a study which compared people treated for SMI and the general population in Massachusetts, USA [2]. Also, using a nationwide hospital discharge registry, a study reported a wide difference in life expectancy at age 30 for the main mental disorder categories compared to the general population, particularly for functional psychosis other than schizophrenia/

affective psychosis (15.9 years lost), substance abuse (15.6 years lost), and

organic psychosis (14.8 years lost) for men and organic psychosis (22.6 years lost), mental retardation (14.7 years lost), and substance abuse (18.8 years lost) for

environment [9–12, 43].

*DOI: http://dx.doi.org/10.5772/intechopen.90756*

race [44].

[44–49].

generation.

**63**

A number of sociodemographic and clinical variables may however serve as key determinants of quality of life and life expectancy. In Nigeria, these medical conditions have remained on the rise [4–9]. Studies have noted a prevalence of 10–15% for diabetes mellitus and 4.6% for HIV infection [4–6]. Worldwide, it was estimated that diabetes affected 285 million adults (20–79 years) in 2010, and this figure would likely increase to about 439 million adults by 2030 [6]. The World Health Organization (WHO) has also estimated that 2 billion people, almost a third of the world's population, have latent TB [7–9] which is one of the leading causes of mortality worldwide [9–11]. About 8 million people develop tuberculosis every year, and out of this number, some 3 million die of it, and over 95% are from developing countries [9–11].

The global prevalence of high blood pressures has been estimated to be between 10 and 15% of adult populations [12], which is also in line with the findings in Africa [13]. However, other studies have reported a worldwide prevalence of 15–30% in adults [14]. The prevalence of hypertension has increased from 11.2% in 1990 to 27.9% in 2010 in rural communities in the Niger Delta and 44.3% in urban Lagos [15–17]. Over 36 million people have contracted HIV infection worldwide, and over 16 million people are said to have died from the disease [4, 11]. The prevalence of cancer diseases, schizophrenia, and dementia have all continued to increase [18–21].

In terms of mode of acquisition, while hypertension, diabetes mellitus, cancer, schizophrenia, and dementia have a clear genetic component, in addition to adverse environmental factors [22, 23], HIV and tuberculosis are mainly acquired infections [24–26]. Furthermore, HIV infection, tuberculosis, and schizophrenia are associated with a high level of stigma and social discrimination [26–29], another strong determinant of the degree of psychological impact of these chronic conditions. It is also worthy of note that while severe emotional trauma can directly cause hypertension, diabetes, and schizophrenia [30–32], it can only predispose an individual to acquiring HIV due to poor sense of judgment, leading to sexual indiscretion and other risk-bearing practices [24–26]. In their late stages, HIV and tuberculosis infections can also cause dementia and mental disorders including schizophrenialike illnesses [33–37].

The choice for their comparison was basically borne out of the observation that they all share some common features in terms of chronicity, with subsequent need for long-term medications, direct or indirect effects on the central nervous system (CNS) [25], high rate of mortality [18–21] and morbidity [32–38], and impact on emotion [33–38]. In addition, patients with these conditions need extensive education, attitudinal change, and coping and healthy lifestyle including diet and exercise [39–42]. The illnesses are equally similar in terms of complications in the central nervous system [21, 23]. Diabetic ketoacidosis, HIV and hypertensive encephalopathies, CNS disseminated tuberculosis, some metastasis to the brain cells, as well as the direct CNS impairment may all directly or indirectly affect the brain cell functions and cognitive ability. This in turn may cause altered sensorium, neuroaffections, neuro-deficits, cognitive impairment, and seizures in some cases. Furthermore, all conditions can directly alter neurotransmitter levels due to direct toxic effects on the brain cells (neurons) either from the viral cells or other opportunistic infections, disseminated tuberculosis to the CNS, hypertensive encephalopathy, or ketoacidotic complication, significantly disrupting relevant neurotransmissions. This may affect particularly the limbic apparatus, the center that regulates mood and controls emotions, anger, and rage.

## *Impact of Chronic Medical and Neuropsychiatric Illnesses on Quality of Life and Life… DOI: http://dx.doi.org/10.5772/intechopen.90756*

It is equally important to note that baseline adverse psychosocial factors or psychological distress have been implicated as predictors of schizophrenia, hypertension and diabetes, or HIV infection [9–12, 43], through impairment of judgment in the later [24–26]. Also, certain environmental as well as socioeconomic factors have been identified to predispose to tuberculosis like living in an overcrowded environment [9–12, 43].

Studies have indicated that life expectancy decreases with each additional chronic condition [1–3]. A study remarked that a 67-year-old person will live on average 22.6 additional years in the absence of any chronic conditions while a 67-year-old person will live 7.7 fewer years and 17.6 fewer years with 5 chronic conditions and ≥10 chronic conditions, respectively [44]. The same study found that the average marginal decline in life expectancy was 1.8 years with each additional chronic condition ranging from 0.4 fewer years with the first condition to 2.6 fewer years with the sixth condition. These results are consistent by sex and race [44].

Another study using a sample of Medicare beneficiaries enrolled as of January 2008, of 21 different chronic conditions and about 1.4 million persons aged 67 and above, found that, on average, a 75-year-old American woman who has no chronic conditions will live 17.3 additional years to more than 92 years old [45]. Conversely, similar individual with five chronic conditions will live, on average, only to age 87, while an individual with 10 or more chronic conditions will survive only to age 80 [45]. Women tend to live longer than men, while white people live longer than black. Clearly, the nature and number of the chronic diseases are important for life expectancy. An individual with heart disease at age 67 is estimated to live an additional 21.2 years on average, while someone of the same age diagnosed with Alzheimer's disease is only expected to live 12 additional years [46]. Different medical conditions have different life expectancy, but this difference gradually decreases with age and more comorbid conditions [44–49].

Struggling with multiple chronic illnesses shortens life expectancy dramatically [45–49], and for older individuals, chronic or multiple chronic conditions equally threaten to reverse recent gains in average life spans. The medical advances and new technologies that have allowed sick people to live longer may not be able to keep up with the growing burden of chronic diseases. It is becoming very clear that preventing the development of additional chronic conditions and giving adequate treatment when they occur in the middle ages and the elderly could be the only way to continue to improve life expectancy. Violence and adverse childhood events are said to speed up aging, and life span continues to increase with each generation.

Concerns about premature mortality among people with chronic mental and medical disorders have been increasing [1–3]. Higher general and specific causes of mortality in all or specific age groups have been identified for people with serious medical and mental illnesses [18–21]. People with chronic and severe mental illness have lower life expectancies of between 13 and more than 30 years than the general population [50], and a loss of 8.8 life years (14.1 years for men and 5.7 years for women) was estimated by a study which compared people treated for SMI and the general population in Massachusetts, USA [2]. Also, using a nationwide hospital discharge registry, a study reported a wide difference in life expectancy at age 30 for the main mental disorder categories compared to the general population, particularly for functional psychosis other than schizophrenia/ affective psychosis (15.9 years lost), substance abuse (15.6 years lost), and organic psychosis (14.8 years lost) for men and organic psychosis (22.6 years lost), mental retardation (14.7 years lost), and substance abuse (18.8 years lost) for

Acting with a number of sociodemographic and clinical variables, they tend to negatively affect life expectancy through, among many other pathways, reducing quality of life. Despite healthcare improvements, there has been little evidence of benefit on

A number of sociodemographic and clinical variables may however serve as key determinants of quality of life and life expectancy. In Nigeria, these medical conditions have remained on the rise [4–9]. Studies have noted a prevalence of 10–15% for diabetes mellitus and 4.6% for HIV infection [4–6]. Worldwide, it was estimated that diabetes affected 285 million adults (20–79 years) in 2010, and this figure would likely increase to about 439 million adults by 2030 [6]. The World Health Organization (WHO) has also estimated that 2 billion people, almost a third of the world's population, have latent TB [7–9] which is one of the leading causes of mortality worldwide [9–11]. About 8 million people develop tuberculosis every year, and out of this number, some 3 million die of it, and over 95% are from

The global prevalence of high blood pressures has been estimated to be between 10 and 15% of adult populations [12], which is also in line with the findings in Africa [13]. However, other studies have reported a worldwide prevalence of 15–30% in adults [14]. The prevalence of hypertension has increased from 11.2% in 1990 to 27.9% in 2010 in rural communities in the Niger Delta and 44.3% in urban Lagos [15–17]. Over 36 million people have contracted HIV infection worldwide, and over 16 million people are said to have died from the disease [4, 11]. The prevalence of cancer diseases, schizophrenia, and dementia have all continued to increase [18–21]. In terms of mode of acquisition, while hypertension, diabetes mellitus, cancer, schizophrenia, and dementia have a clear genetic component, in addition to adverse environmental factors [22, 23], HIV and tuberculosis are mainly acquired infections [24–26]. Furthermore, HIV infection, tuberculosis, and schizophrenia are associated with a high level of stigma and social discrimination [26–29], another strong determinant of the degree of psychological impact of these chronic conditions. It is also worthy of note that while severe emotional trauma can directly cause hypertension, diabetes, and schizophrenia [30–32], it can only predispose an individual to acquiring HIV due to poor sense of judgment, leading to sexual indiscretion and other risk-bearing practices [24–26]. In their late stages, HIV and tuberculosis infections can also cause dementia and mental disorders including schizophrenia-

The choice for their comparison was basically borne out of the observation that they all share some common features in terms of chronicity, with subsequent need for long-term medications, direct or indirect effects on the central nervous system (CNS) [25], high rate of mortality [18–21] and morbidity [32–38], and impact on emotion [33–38]. In addition, patients with these conditions need extensive education, attitudinal change, and coping and healthy lifestyle including diet and exercise [39–42]. The illnesses are equally similar in terms of complications in the central nervous system [21, 23]. Diabetic ketoacidosis, HIV and hypertensive encephalopathies, CNS disseminated tuberculosis, some metastasis to the brain cells, as well as the direct CNS impairment may all directly or indirectly affect the brain cell functions and cognitive ability. This in turn may cause altered sensorium, neuroaffections, neuro-deficits, cognitive impairment, and seizures in some cases. Furthermore, all conditions can directly alter neurotransmitter levels due to direct toxic effects on the brain cells (neurons) either from the viral cells or other opportunistic infections, disseminated tuberculosis to the CNS, hypertensive encephalopathy, or ketoacidotic complication, significantly disrupting relevant neurotransmissions. This may affect particularly the limbic apparatus, the center that regulates mood

life expectancy in people with chronic medical and mental disorders [1–3].

developing countries [9–11].

*Aging - Life Span and Life Expectancy*

like illnesses [33–37].

and controls emotions, anger, and rage.

**62**

women [46]. Emphasis has been made on management of suicide risk and physical illness, minimum polypharmacy, and improvement of accessibility to physical healthcare [51].

Mutations in the genes that code for outer membrane proteins can produce changes in the protein's structure, and if the key then no longer fits the lock, the genetic mutations allow the bacterium or virus to evade recognition by antibodies [9, 25, 29]. The intense selective pressure on the disease-causing microorganism to survive the immune response, coupled with increased

*Impact of Chronic Medical and Neuropsychiatric Illnesses on Quality of Life and Life…*

mutation rates, produces the incredibly fast rate of genomic change in infectious organisms. Mutations occur randomly throughout the genome, but because they help the microorganism avoid elimination by the immune system, changes in outer membrane proteins appear much more often than would be expected by chance in the surviving organism. Furthermore, this initial burst of mutations during the acute phase of infection allows the bacteria or virus to survive the host's immune response, and this helps to establish a chronic infection

including HIV and tuberculosis. In addition, the already weakened or compromised

The chronicity of these medical illnesses, persistent and recurrent symptoms, impairment in functioning capacity, other adverse and enduring environmental psychosocial burdens, and even the thought of these can also in turn affect quality of life and subsequently lower life expectancy. Although HIV- and tuberculosisinfected and cancer-affected patients under antiretroviral (arbacire, nevirapine), antituberculosis drug (isoniazid and cycloserine), and anticancer medication (methotrexate) therapy infrequently suffer acute organic psychotic complications, the chronicity of the disease places them at greater risk for psychiatric comorbidity

The terms "quality of life" refers to the physical, psychological, and social domains of health, viewed as distinct areas that are influenced by a person's experiences, beliefs, expectations, and perception [78], ("which is referred to here collectively as perceptions of health"). Two things are significant in the above definition: the first is the subjective nature of QOL, and second is the need for a Clinician to assess all those areas of life considered as having significant impact on QOL. Quality of life assessment measures changes in physical, functional, mental, and social health in order to evaluate the human and financial cost and benefits of new

Quality of life therefore is impaired in many ways by the individual's level of independence, social relationships, personal beliefs, and their relationship to salient features of the environment in addition to their physical health and psychological state. Quality of life also consists of fulfilling needs, meeting of social expectations, and assessing opportunities by using abilities. Abilities are impaired by ill health and worse still chronic medical illnesses [78, 79]. The services rendered by healthcare givers in mental health help to moderate social demands, supplement opportunities, and restore abilities. Quality of life can be altered by both the immediate and the long-term consequences of treatment especially the case of chronic illnesses [80]. Since 1948, when the WHO defined health as being not only the absence of disease and infirmity but also the presence of physical, mental, and social well-being, quality-of-life issues and well-being have taken the center stage in healthcare practices and research [78, 79, 81]. Several studies have shown that chronic medical and mental illnesses often impair or have negative impacts on the quality of life and subjective well-being of persons across a whole range of areas

There has been a growing interest during the past decades for assessing determinant factors of patients' health-related quality of life (HRQOL), especially in

immunity sets a vulnerable pace for repeated reinfections or other new infections [24–29]. These infections eventually become chronic and invariably

affect longevity.

[80, 82–89].

**65**

than the general population [63–77].

*DOI: http://dx.doi.org/10.5772/intechopen.90756*

programs and interventions [78, 79].

Social security and different forms of life insurance policies have greatly helped in stabilizing life expectancy; in spite of this, a growing number of beneficiaries with multiple chronic conditions still have reduced life expectancy. The burden and stress of chronic disease could erase decades of progress. Life expectancy in the USA is rising more slowly than in other parts of the developed world. Many blame the obesity epidemic and related health conditions for the worsening health of the American population.

Functional limitations, including difficulty walking across the room or preparing meals, and health problems, such as high blood pressure, cancer, and diabetes, also predicted greater odds of experiencing a fall for adults 65 and older. Previous research indicates that older African Americans were more likely to live in extended family households. The availability of assistance at home could help older adults avoid scenarios or behaviors that could lead to falls.

Medication side effect is another important factor influencing longevity [51–57]. People with chronic illness tend to stay compliant longer on medications with less side effect profiles. For example, many people living with HIV find it difficult to continue the treatment regimen due to the side effects [53, 58]. Hence, decreasing the toxicity and side effects of HIV drugs will increase longevity, as this will increase their life span by increasing the amount of time that patients can stay on the life-saving treatment regimen and also increase quality of life [52–54]. Similarly, the antituberculosis and anticancer drugs are known to have serious side effects that can impair drug compliance, thereby reducing the life span of the affected individual [55–57, 59–62]. Bringing new drugs to market is an essential part of increasing the life expectancy of young people with HIV, but lowering the drugs' toxicity may have even greater health benefits for all HIV patients [52, 54]. Some side effects, such as increased cardiovascular risk, also cause problems that directly contribute to premature mortality and reduced life.

In spite of the current drug toxicity levels, young people with HIV add nearly 2 years to their lives by initiating HIV treatment regimens soon after infection [52]. If a new drug has a low toxicity and is well-tolerated by the patients, then they are more likely to take it regularly so that it is as effective as possible, and this will add to their life span. Reduction in the toxicity of new drugs has been associated with increase in the patient's quality-adjusted life expectancy by as much as 11%, or more than 3 years [52]. "Quality-adjusted life years" and "quality-adjusted life expectancy" are measures that are used to determine the value of different medical actions. For example, a potentially life-saving drug that is highly toxic, causes so much discomfort, and leaves a patient debilitated would have a lower value than a life-saving drug that does not have such side effects. Furthermore, there exists the negative psychological impact of being on medications for a long time (and in some cases a lifetime), which is in turn detrimental on quality of life and longevity.

Infectious diseases are a significant health concern especially in developing countries, and this has significantly contributed to life expectancy [24–29]. Of particular importance is the interface between the immune system and invading bacteria or virus and the proteins that protrude through the outer cell membrane of the bacteria or virus. Because these outer membrane proteins are on the outside of the antigenic cells, they are visible to the human immune system and therefore are targeted by antibodies. Antibodies are so tuned to recognize the three-dimensional structure of outer membrane proteins that they can attach to them with lock-and-key specificity, thereby labeling the foreign bacteria cell for elimination.

## *Impact of Chronic Medical and Neuropsychiatric Illnesses on Quality of Life and Life… DOI: http://dx.doi.org/10.5772/intechopen.90756*

Mutations in the genes that code for outer membrane proteins can produce changes in the protein's structure, and if the key then no longer fits the lock, the genetic mutations allow the bacterium or virus to evade recognition by antibodies [9, 25, 29]. The intense selective pressure on the disease-causing microorganism to survive the immune response, coupled with increased mutation rates, produces the incredibly fast rate of genomic change in infectious organisms. Mutations occur randomly throughout the genome, but because they help the microorganism avoid elimination by the immune system, changes in outer membrane proteins appear much more often than would be expected by chance in the surviving organism. Furthermore, this initial burst of mutations during the acute phase of infection allows the bacteria or virus to survive the host's immune response, and this helps to establish a chronic infection including HIV and tuberculosis. In addition, the already weakened or compromised immunity sets a vulnerable pace for repeated reinfections or other new infections [24–29]. These infections eventually become chronic and invariably affect longevity.

The chronicity of these medical illnesses, persistent and recurrent symptoms, impairment in functioning capacity, other adverse and enduring environmental psychosocial burdens, and even the thought of these can also in turn affect quality of life and subsequently lower life expectancy. Although HIV- and tuberculosisinfected and cancer-affected patients under antiretroviral (arbacire, nevirapine), antituberculosis drug (isoniazid and cycloserine), and anticancer medication (methotrexate) therapy infrequently suffer acute organic psychotic complications, the chronicity of the disease places them at greater risk for psychiatric comorbidity than the general population [63–77].

The terms "quality of life" refers to the physical, psychological, and social domains of health, viewed as distinct areas that are influenced by a person's experiences, beliefs, expectations, and perception [78], ("which is referred to here collectively as perceptions of health"). Two things are significant in the above definition: the first is the subjective nature of QOL, and second is the need for a Clinician to assess all those areas of life considered as having significant impact on QOL. Quality of life assessment measures changes in physical, functional, mental, and social health in order to evaluate the human and financial cost and benefits of new programs and interventions [78, 79].

Quality of life therefore is impaired in many ways by the individual's level of independence, social relationships, personal beliefs, and their relationship to salient features of the environment in addition to their physical health and psychological state. Quality of life also consists of fulfilling needs, meeting of social expectations, and assessing opportunities by using abilities. Abilities are impaired by ill health and worse still chronic medical illnesses [78, 79]. The services rendered by healthcare givers in mental health help to moderate social demands, supplement opportunities, and restore abilities. Quality of life can be altered by both the immediate and the long-term consequences of treatment especially the case of chronic illnesses [80]. Since 1948, when the WHO defined health as being not only the absence of disease and infirmity but also the presence of physical, mental, and social well-being, quality-of-life issues and well-being have taken the center stage in healthcare practices and research [78, 79, 81]. Several studies have shown that chronic medical and mental illnesses often impair or have negative impacts on the quality of life and subjective well-being of persons across a whole range of areas [80, 82–89].

There has been a growing interest during the past decades for assessing determinant factors of patients' health-related quality of life (HRQOL), especially in

women [46]. Emphasis has been made on management of suicide risk and physical illness, minimum polypharmacy, and improvement of accessibility to physical

Social security and different forms of life insurance policies have greatly helped in stabilizing life expectancy; in spite of this, a growing number of beneficiaries with multiple chronic conditions still have reduced life expectancy. The burden and stress of chronic disease could erase decades of progress. Life expectancy in the USA is rising more slowly than in other parts of the developed world. Many blame the obesity epidemic and related health conditions for the worsening health of the

Functional limitations, including difficulty walking across the room or preparing meals, and health problems, such as high blood pressure, cancer, and diabetes, also predicted greater odds of experiencing a fall for adults 65 and older. Previous research indicates that older African Americans were more likely to live in extended family households. The availability of assistance at home could help older adults

Medication side effect is another important factor influencing longevity [51–57]. People with chronic illness tend to stay compliant longer on medications with less side effect profiles. For example, many people living with HIV find it difficult to continue the treatment regimen due to the side effects [53, 58]. Hence, decreasing the toxicity and side effects of HIV drugs will increase longevity, as this will increase their life span by increasing the amount of time that patients can stay on the life-saving treatment regimen and also increase quality of life [52–54]. Similarly, the antituberculosis and anticancer drugs are known to have serious side effects that can impair drug compliance, thereby reducing the life span of the affected individual [55–57, 59–62]. Bringing new drugs to market is an essential part of increasing the life expectancy of young people with HIV, but lowering the drugs' toxicity may have even greater health benefits for all HIV patients [52, 54]. Some side effects, such as increased cardiovascular risk, also cause problems that directly contribute to

In spite of the current drug toxicity levels, young people with HIV add nearly 2 years to their lives by initiating HIV treatment regimens soon after infection [52]. If a new drug has a low toxicity and is well-tolerated by the patients, then they are more likely to take it regularly so that it is as effective as possible, and this will add to their life span. Reduction in the toxicity of new drugs has been associated with increase in the patient's quality-adjusted life expectancy by as much as 11%, or more than 3 years [52]. "Quality-adjusted life years" and "quality-adjusted life expectancy" are measures that are used to determine the value of different medical actions. For example, a potentially life-saving drug that is highly toxic, causes so much discomfort, and leaves a patient debilitated would have a lower value than a life-saving drug that does not have such side effects. Furthermore, there exists the negative psychological impact of being on medications for a long time (and in some cases a lifetime), which is in turn detrimental on quality of life and longevity.

Infectious diseases are a significant health concern especially in developing countries, and this has significantly contributed to life expectancy [24–29]. Of particular importance is the interface between the immune system and invading bacteria or virus and the proteins that protrude through the outer cell membrane of the bacteria or virus. Because these outer membrane proteins are on the outside of the antigenic cells, they are visible to the human immune system and therefore are targeted by antibodies. Antibodies are so tuned to recognize the three-dimensional structure of outer membrane proteins that they can attach to them with lock-and-key specificity,

thereby labeling the foreign bacteria cell for elimination.

**64**

healthcare [51].

*Aging - Life Span and Life Expectancy*

American population.

avoid scenarios or behaviors that could lead to falls.

premature mortality and reduced life.

chronic diseases [78–89]. Diabetes mellitus, HIV, tuberculosis, hypertensive, cancer, schizophrenia, and dementia are some of these chronic diseases that involve people of all races and to some extent all ages. They are considered common chronic diseases in most countries, and their prevalence has continued to increase. Several studies have shown that chronic illnesses often impair or have negative impacts on the quality of life and subjective well-being of persons across a whole range of areas [80, 82–89].

**4. Results**

*DOI: http://dx.doi.org/10.5772/intechopen.90756*

**Age**

**Sex**

**Marital status**

**Education**

**Occupation**

Clerical support workers

Service and sales workers

Skilled agricultural forestry and fishery workers

Craft and related trade workers

Plant and machine operators and assemblers

Elementary occupation

Armed forces occupation

**Income**

**Table 1.**

**67**

*and dementia.*

**Variable DM Hypertension HIV TB Cancer Schizo Dementia**

*Impact of Chronic Medical and Neuropsychiatric Illnesses on Quality of Life and Life…*

30–39 years 9 (45%) 6 (30%) 12 (60%) 9 (45%) 7 (35%) 11 (55%) 0 (0%) 40–49 years 11 (55%) 14 (70%) 8 (40%) 11 (55%) 13 (65%) 9 (45%) 20 (100%)

Female 12 (60%) 10 (50%) 10 (50%) 9 (45%) 10 (50%) 12 (60%) 11 (55%) Male 8 (40%) 10 (50%) 10 (50%) 11 (55%) 10 (50%) 8 (40%) 9 (54%)

Married 10 (50%) 8 (40%) 8 (40%) 9 (45%) 12 (60%) 6 (30%) 14 (70%) Divorce 2 (10%) 1 (5%) 2 (10%) 3 (15%) 2 (10%) 0 (0%) 0 (0%) Separated 3 (15%) 3 (15%) 3 (15%) 3 (15%) 1 (5%) 5 (25%) 3 (15%) Single 3 (15%) 4 (20%) 6 (30%) 4 (20%) 3 (15%) 9 (45%) 1 (5%) Widowed 2 (10%) 4 (20%) 1 (5%) 1 (5%) 1 (5%) 0 (0%) 2 (10%)

Primary 2 (10%) 3 (15%) 3 (15%) 3 (15%) 2 (10%) 2 (10%) 2 (10%) Secondary 8 (40%) 7 (35%) 4 (20%) 7 (35%) 6 (30%) 10 (50%) 5 (25%) Tertiary 9 (45%) 8 (40%) 7 (35%) 7 (35%) 11 (55%) 7 (35%) 13 (65%) None 1 (5%) 2 (10%) 1 (5%) 3 (15%) 0 (0%) 1 (5%) 0 (0%)

Managers 2 (10%) 1 (5%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 3 (15%) Professionals 3 (15%) 1 (5%) 1 (5%) 0 (0%) 4 (20%) 0 (0%) 4 (20%)

5 (25%) 5 (25%) 4 (20%) 5 (25%) 4 (20%) 0 (0%) 2 (10%)

2 (10%) 4 (20%) 4 (20%) 5 (25%) 3 (15%) 3 (15%) 3 (15%)

4 (20%) 5 (25%) 2 (10%) 4 (20%) 2 (10%) 4 (20%) 2 (10%)

2 (10%) 1 (5%) 4 (20%) 3 (15%) 3 (15%) 4 (20%) 2 (10%)

1 (5%) 1 (5%) 3 (15%) 1 (5%) 2 (10%) 3 (15%) 1 (5%)

1 (5%) 1 (5%) 2 (10%) 2 (10%) 2 (10%) 6 (30%) 1 (5%)

0 (0%) 1 (5%) 1 (5%) 0 (0%) 0 (0%) 0 (0%) 0 (0%)

Low 5 (25%) 4 (20%) 8 (40%) 9 (45%) 6 (30%) 11 (55%) 7 (35%) Average 13 (65%) 14 (70%) 11 (55%) 10 (50%) 18 (90%) 9 (45%) 6 (30%) High 2 (10%) 2 (10%) 1 (5%) 1 (5%) 1 (5%) 0 (0%) 7 (35%)

*Sociodemographic variables of patients with diabetes, hypertension, HIV, tuberculosis, cancer schizophrenia,*

Tuberculosis, HIV, and cancer diseases weaken patients' physical functioning and impair their quality of life and hence may affect life expectancy [82–85]. It has become important that TB and HIV control programs as well as cancer awareness and prevention programs at public health clinics design strategies to improve the quality of health and life of these patients. In patients with chronic diseases, all predicted domains of quality of life (QOL), including general health perceptions, somatic sensation, psychological health, spiritual well-being, and physical, social, and role functioning, all tend to be negatively affected [86–93]. Social stigmatization, isolation, pill burden, long duration of therapy, sexual dysfunction, loss of income, and fear were additional specific problems related to chronic medical conditions [80, 82–88]. Despite available curative therapy, TB and its treatment still have significant short- and long-term consequences on patients' QOL [82, 83, 86–93]. QOL has also been characterized as "the ultimate goal of all health interventions" [81].
