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Mental Health and Mental Disorders

Mental Health and Mental Disorders


Improve mental health through prevention and by ensuring access to appropriate, quality mental health services.


Mental health is a state of successful performance of mental function, resulting in productive activities, fulfilling relationships with other people, and the ability to adapt to change and to cope with challenges. Mental health is essential to personal well-being, family and interpersonal relationships, and the ability to contribute to community or society.

Mental disorders are health conditions that are characterized by alterations in thinking, mood, and/or behavior that are associated with distress and/or impaired functioning. Mental disorders contribute to a host of problems that may include disability, pain, or death.

Mental illness is the term that refers collectively to all diagnosable mental disorders.

Why Is Mental Health Important?

Mental disorders are among the most common causes of disability. The resulting disease burden of mental illness is among the highest of all diseases. In any given year, an estimated 18.1% (43.6 million) of U.S. adults ages 18 years or older suffered from any mental illness and 4.2% (9.8 million) suffered from a seriously debilitating mental illness.1 Neuropsychiatric disorders are the leading cause of disability in the United States, accounting for 18.7% of all years of life lost to disability and premature mortality.2 Moreover, suicide is the 10th leading cause of death in the United States, accounting for the deaths of approximately 43,000 Americans in 2014.3,4

Mental health and physical health are closely connected. Mental health plays a major role in people’s ability to maintain good physical health. Mental illnesses, such as depression and anxiety, affect people’s ability to participate in health-promoting behaviors. In turn, problems with physical health, such as chronic diseases, can have a serious impact on mental health and decrease a person’s ability to participate in treatment and recovery.5

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Understanding Mental Health and Mental Disorders

The existing model for understanding mental health and mental disorders emphasizes the interaction of social, environmental, and genetic factors throughout the lifespan. In behavioral health, researchers identify:

  • Risk factors, which predispose individuals to mental illness
  • Protective factors, which protect them from developing mental disorders

Researchers now know that the prevention of mental, emotional, and behavioral (MEB) disorders is inherently interdisciplinary and draws on a variety of different strategies.6

Over the past 20 years, research on the prevention of mental disorders has progressed. The understanding of how the brain functions under normal conditions and in response to stressors, combined with knowledge of how the brain develops over time, has been essential to that progress. The major areas of progress include evidence that:

  • MEB disorders are common and begin early in life
  • The greatest opportunity for prevention is among young people
  • There are multiyear effects of multiple preventive interventions on reducing substance abuse, conduct disorder, antisocial behavior, aggression, and child maltreatment
  • The incidence of depression among pregnant women and adolescents can be reduced
  • School-based violence prevention can reduce the base rate of aggressive problems in an average school by 25 to 33 percent
  • There are potential indicated preventive interventions for schizophrenia
  • Improving family functioning and positive parenting can have positive outcomes on mental health and can reduce poverty-related risk
  • School-based preventive interventions aimed at improving social and emotional outcomes can also improve academic outcomes
  • Interventions targeting families dealing with adversities, such as parental depression or divorce, can be effective in reducing risk for depression among children and increasing effective parenting
  • Some preventive interventions have benefits that exceed costs, with the available evidence strongest for early childhood interventions
  • Implementation is complex, and it is important that interventions be relevant to the target audiences

The progress identified above has led to a stronger understanding of the importance of protective factors. A 2009 Institute of Medicine (IOM) report advocates for multidisciplinary prevention strategies at the community level that support the development of children in healthy social environments.7 In addition to advancements in the prevention of mental disorders, there continues to be steady progress in treating mental disorders as new drugs and stronger evidence-based outcomes become available.

Emerging Issues in Mental Health and Mental Disorders

New mental health issues have emerged among some special populations, such as:

  • Veterans who have experienced physical and mental trauma
  • People in communities with large-scale psychological trauma caused by natural disasters
  • Older adults, as the understanding and treatment of dementia and mood disorders continues to improve

As the Federal Government begins to implement the health reform legislation, it will give attention to providing services for individuals with mental illness and substance use disorders, including new opportunities for access to and coverage for treatment and prevention services.


1Center for Behavioral Health Statistics and Quality. Behavioral health trends in the United States: Results from the 2014 National Survey on Drug Use and Health. 2015. HHS Publication No. SMA 15-4927, NSDUH Series H-50. Available from

2US Burden of Disease Collaborators. The state of US health, 1990-2010: burden of diseases, injuries, and risk factors. JAMA, 310(6): 591-608, 2013. 

3Centers for Disease Control and Prevention (CDC), National Center for Injury Prevention and Control (NCIP). Web-based injury statistics query and reporting system (WISQARS) [Internet]. Atlanta: CDC; 2014. Available from:

4National Institutes of Health, National Institute of Mental Health (NIMH). NIMH strategic plan (revised 2008) [Internet]. Bethesda, MD: NIMH; 2008 [cited 2010 May 6]. Available from:

5Lando J, Marshall Williams S, Sturgis S, et al. A logic model for the integration of mental health into chronic disease prevention and health promotion. Prev Chronic Dis. 2006 April;3(2):A61. 

6National Research Council and Institute of Medicine, Committee on the Prevention of Mental Disorders and Substance Abuse Among Children, Youth, and Young Adults. Preventing mental, emotional, and behavioral disorders among young people: Progress and possibilities [Internet]. O’Connell ME, Boat T, Warner KE, editors. Washington: National Academies Press; 2009. p. 562. Available from:

7National Research Council and Institute of Medicine, Committee on the Prevention of Mental Disorders and Substance Abuse Among Children, Youth, and Young Adults. Preventing mental, emotional, and behavioral disorders among young people: Progress and possibilities [Internet]. O’Connell ME, Boat T, Warner KE, editors. Washington: National Academies Press; 2009. p. 18. Available from:

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