Module 1: Introduction to Global Mental Health: Effects of Mental Health on Individuals and Populations

The World Health Organization (WHO) recognizes the importance of psychological well-being, defining health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”.(1) In 2018, of the estimated 792 million people worldwide living with mental or behavioral disorder (roughly 10.7% of the global population), 178 million were drug or alcohol dependent, 20 million were diagnosed with schizophrenia, and 264 million suffered from depression.(2)

Though most efforts to improve global mental health focus on improving care for individuals living with psychological disorders, the WHO stresses that a comprehensive definition of mental health should extend beyond the absence or presence of diagnosable psychological disorders to include “subjective well-being, perceived self-efficacy, autonomy, competence, intergenerational dependence and recognition of the ability to realize one’s intellectual and emotional potential”.(3) Although the following modules will focus on the public health implications of psychological disorders, mental health delivery programs should utilize this more inclusive definition of mental health.   

While it is often overlooked as a public health issue due to a historical focus on communicable and more immediately life-threatening diseases (such as HIV/AIDS and malaria), mental health has profound effects on an individual’s quality of life, physical and social well-being, and economic productivity.(4) Because psychological disorders also affect families and communities of the mentally ill, understanding the effects of mental illness on individual patients and social systems is necessary for the improvement of mental health care systems and the development of effective mental health care delivery programs.

Effects of Psychological Disorders on the Patient

Individuals with psychological disorders are at greater risk for decreased quality of life, educational difficulties, lowered productivity and poverty, social problems, vulnerability to abuse, and additional health problems. Education is often compromised when early-onset mental disorders prevent individuals from completing their education or successfully pursuing a career. Kessler et al. (1995) found that individuals with a psychological disorder were significantly less likely to complete high school, enter college, or receive a college degree, compared to their peers without mental illness.(5) In addition, psychological disorders result in lowered individual productivity due to unemployment, missed work, and reduced productivity at work. A 2001 study found that five to six million U.S. workers aged 16 to 54 years “lose, fail to seek, or cannot find employment” due to mental illness. Of mentally ill individuals who were employed, mental illness was estimated to reduce their annual income by $3,500 to $6,000.(6) Reduced earnings and decreased employment potential put mentally ill individuals at an increased risk of poverty. As Lund et al. (2011) explain, mental illness and poverty “interact in a negative cycle”, in which poverty acts as a risk factor for mental illness, and mental illness increases the risk that individuals will “drift into or remain in poverty”.(7) This negative cycle may also contribute to high rates of homelessness among individuals with mental illness; the Substance Abuse and Mental Health Services Administration estimates that 20 to 25 % of the U.S. homeless population suffers from severe mental illness, while only 6% of the general U.S. population is severely mentally ill.(8)

Psychological disorders can also contribute to other health problems and stressors.  For instance, patients with comorbid depression (depression co-occurring with another health condition) are three times less likely to adhere to medical treatment regimens than are non-depressed patients.(9) Furthermore, mentally ill individuals are vulnerable to low-quality care, abuse, and human rights violations, particularly in low-income areas with limited mental health care resources.(10)  Mentally ill individuals and their families may also experience significant social stigma and discrimination.  Please see Module 7: Cultural Perspectives on Mental Health for further information on attitudes towards mental illness. 

Effects of Psychological Disorders on Families/Caregivers

The burden of caring for a mentally ill individual often falls on the patient’s immediate family or relatives. Families and caregivers of individuals with psychological disorders are often unable to work at full capacity due to the demands of caring for a mentally ill individual, leading to decreased economic output and a reduction in household income. Loss of income and the financial costs of caring for a mentally ill person put these households at an increased risk of poverty. Family members may also experience significant and chronic stress due to the emotional and physical challenges of caring for a mentally ill family member.(11)  Family members of mentally ill individuals are faced with a considerable amount of emotional upheaval; parents are tasked with readjusting parental methods and expectations, while partners must exude a considerable amount of patience and empathy in order to provide appropriate care. These responsibilities may weigh heavily upon the family members, depending on individual experience and culture, and must be given equal importance when discussing the residual effects of mental illness on society.(12) 

For instance, a 2006 study in Botswana investigated the experiences of families caring for a mentally ill family member. The study was conducted using in-depth interviews, focus group discussions, and field observations in Gaborone, the capital city, and Molepolole, a rural village. Although the extended family structure common in Botswana allowed for distribution of caregiver responsibilities, most families reported that lack of financial and medical resources at the family and community levels made it difficult and stressful to provide adequate care.(13) In South Africa, in-depth interviews with eight family caregivers in Limpopo revealed that many caregivers felt that their own physical and mental well-being was at risk, particularly when caring for a violent or destructive family member. Caregivers also reported social isolation due to their family member’s mental illness, as caregiving duties prevented them from attending social events such as funerals and church services.(14) Particularly in rural areas lacking community resources for the mentally ill, the degree of satisfaction with family functioning (perception of “family burden”) and the size of a caregiver’s support network may significantly influence patient functioning, with increased support improving patient outcomes even in cases with high reported family burden.(15)

Effects of Psychological Disorders on Society

Although the specific societal impact of mental illness varies among cultures and nations, untreated mental illness has significant costs to society. In 2001, the WHO estimated that mental health problems cost developed nations between three and four % of their GNP (gross national product). A 2018 Lancet Commission report on mental health has stated that mental disorders are on the rise in every country in the world and will cost the global economy an estimated $16 trillion by 2030. The economic cost is primarily due to early onset of mental illness and lost productivity, with an estimated 12 billion working days lost due to mental illness every year.(16) In 1997, a Harvard Medical School study estimated that the United States lost more than 4 million workdays and experienced 20 million “work cutback days” (days of impaired workplace performance) due to mental illness.(17)

In addition, psychological disorders can exacerbate other public health issues, increasing the burden on national economies and impeding international public health efforts. According to a 2020 WHO report, around 13 million people inject drugs globally, and 1.7 million of them are living with HIV. Injecting drug use accounts for approximately 10% of HIV infections globally and 30% of those outside of Africa. Regional HIV prevalence rates are high in people who inject drugs in all parts of the world (up to 15.5% in East and Southern Africa).(18) People who use drugs are also disproportionately affected by hepatitis C. The estimated global prevalence of hepatitis C in people who inject drugs is 67%. Further, worldwide there are approximately 2.2 million HIV–hepatitis C virus co-infections of which more than half are in people who inject drugs. Mental illnesses are also associated with increased risk of non-adherence to medical regimens for other health conditions. For infectious diseases, improper or incomplete use of medication can lead to drug resistance, which may have “profound public health implications” for the global community.(19) Furthermore, maternal depression may put infants at increased risk of low birth weight, childhood health problems, and “incomplete immunization”, all of which are risk factors for childhood mortality.(20)

Although the majority of individuals with mental illness do not exhibit dangerous behaviors, violence and incarceration among mentally ill individuals can place a significant financial and social burden on communities and nations. Worldwide, approximately 10 million people are incarcerated, and the WHO reports that the prevalence of mental health problems is “very high”, especially among female inmates.(21) In the U.S. in the late 2000s, nearly one million adults with serious psychological disorders were incarcerated annually. A study in the Pinellas Country, Florida jail found that not having outpatient mental health treatment was significantly associated with increased risk of misdemeanor arrests and days incarcerated, and having a substance abuse disorder was associated with more days in jail, which is consistent with national incarceration statistics.(22) National data from the 2002 Survey of Inmates in Local Jails revealed that homelessness was significantly more prevalent among the inmate population as compared to the general U.S. adult population, and inmates who had been homeless were significantly more likely than were other inmates to have mental health and substance abuse problems. The authors posit that the relationship between homelessness and mental illness “may reflect limited access to mental health services, particularly inpatient services”, due to deinstitutionalization in the United States, which has resulted in limited availability of psychiatric hospital beds, and strict criteria for hospitalization.(23) The WHO recommends that developing and developed nations adopt more comprehensive preventative and interventional mental health programs to reduce the negative effects of mental illness on patients  and their local and global communities.(24)

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(1) World Health Organization. (2003). Investing in Mental Health.

(2) Ritchie, H., Roser, M. (2018). Mental Health.

(3) Ibid.

(4) Ibid.

(5) Kessler, R.C., Foster, C.L., Saunders, W.B., Stang, P.E. (1995). Social consequences of psychiatric disorders, I: Educational attainment. American Journal of Psychiatry, 152(7): 1026–1032.

(6) Marcotte, D.E., Wilcox-Gok, V. (2001). Estimating the employment and earnings costs of mental illness: Recent developments in the United States. Social Science & Medicine, 53 (1): 21-27.

(7) Lund, C., DeSilva, M., Plagerson, S., Cooper, S., Chisholm, D., Das, Jishnu, Knapp, M., Patel, V. (2011). Poverty and mental disorders: breaking the cycle in low-income and middle-income countries. Lancet, 378: 1502-14.

(8) National Institute of Mental Health. “Statistics.” March 2009.

(9) World Health Organization. 2003. “Investing in Mental Health”.

(10) Ibid.

(11) Ibid.

(12) American Psychological Association. (2015). How to cope when a loved one has a serious mental illness.

(13) Seloilwe, E.S. (2006). Experiences and demands of families with mentally people at home in Botswana. Journal of Nursing Scholarship, 38(3): 262-268.

(14) Mavundla, T.R., Toth, F., Mphelane, M.L. (2009). Caregiver experience in mental illness: a perspective from a rural community in South Africa.  International Journal of Mental Health Nursing, 18: 357-367.

(15) Kohn-Wood, L.P., Wilson, M.N. (2005). The context of caretaking in rural areas: family factors influencing the level of functioning of seriously mentally ill patients living at home. American Journal of Community Psychology, 36(1-2): 1-13.

(16) Patel, V., Saxena, S., Lund, C., Thornicroft, G., Baingana, F., Bolton, P. (2018). The Lancet Commission on global mental health and sustainable development. The Lancet. doi:

(17) Kessler, R.C., Frank, R.G. (1997). The impact of psychiatric disorders on work loss days. Psychological Medicine, 27(4): 861–873.

(18) World Health Organization. (2020). People who inject drugs.

(19) Ibid.

(20) Patek, V. (2007). Mental health in low- and middle-income countries. British Medical Bulletin, 81-82: 81-96.

(21) van den Bergh, B.J., Gatherer, A., Fraser, A., Moller, L. (2011). Imprisonment and women’s health: concerns about gender sensitivity, human rights, and public health. Bull World Health Organ, 89: 689-694.

(22) Constantine, R., Andel, R., Petrila, J., Becker, M., Robst, J., Teague, G., Boaz, T., Howe, A. (2010). Characteristics and experiences of adults with a serious mental illness who were involved in the criminal justice system. Psychiatric Services, 61(5): 451-458.

(23) Greenberg, G.A., Rosenheck, R.A. (2008). Jail incarceration, homelessness, and mental health: a national study. Psychiatric Services, 59(2): 170-177.

(24) World Health Organization. 2003. “Investing in Mental Health”.