Behind the Term: Serious Mental Illness
Related terms: chronic mental illness, severe and persistent mental illness, serious and persistent
mental illness, severe mental illness, schizophrenia, schizoaffective disorders, delusional disorder, manic–
depressive disorder, major depressive disorder, bipolar and related disorders, psychotic disorders,
posttraumatic stress disorder, obsessive-compulsive disorder, substance use disorders, eating and feeding
disorders, affective disorders, and mood disorders

T

he terms chronic mental illness, serious mental illness, serious and persistent mental illness,
severe and persistent mental illness, and severe mental illness are often used interchangeably;
however, the most current terms used to refer to mental disorders
requiring routine management are “serious mental illness” and “severe and persistent mental
illness”. The terms “serious and persistent mental illness” and “seriously and persistently
mentally ill” evolved from the term “chronically mentally ill”. However, with recognition that
not all forms of serious mental illness are chronic and that persons diagnosed with a serious
mental illness can be responsive to treatment, services, and recovery supports, “chronic” and
“persistent” have been dropped from the federal definition and “mentally ill” has been replaced
by person-first language (i.e., persons with serious mental illness).
Serious mental illness (SMI) and severe and persistent mental illness (SPMI) refer to distinct conditions;
this is because, although all forms of serious mental illness may be disabling in some way, they are
not always severe and persistent (that is, chronic and always disabling). So, although all severe
and persistent mental illness may be serious, not all serious mental illness may be severe or
persistent. Many mental health professionals, consumers, peers, and advocates use the term SMI
to refer to severe mental illness, while the federal agencies use the term to refer to serious mental
illness. Given this context and the potential for confusion and labeling effects, it may be best to
avoid the acronym.
It is also important to note that definitions of serious mental illness vary, depending on whether
the term is used for legal purposes (to establish eligibility for disability or supplemental social
security benefits), clinical purposes, or epidemiological purposes (to track its prevalence and
incidence over time). Although legal definitions may vary, epidemiological definitions must be
based on standardized measures (such as questions used by the National Survey of Drug Use and
Behind the Term: Serious Mental Illness

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 Health) and remain stable over time. For clinical assessment and treatment purposes, a more
multidisciplinary, biosocial approach for defining serious mental illness is needed.
The federal definition of serious mental illness resulted from a mandate from the 1992 Alcohol,
Drug Abuse, and Mental Health Administration (ADAMHA) Reorganization Act (Public Law
No. 102–321).This definition was created by the U.S. Department of Health and Human Services
to help states applying for grant funds to support mental health services estimate the incidence
and prevalence of serious mental illness (58 Fed. Reg. 96, 292425, 1993). Federal use of the term
chronic mental illness dissolved, however, when consumers and advocates argued that the term
had negative connotations, suggesting that some forms of mental illness are intractable
(Goldman & Grob, 2006). As a result, chronic mental illness was changed to severe and persistent
mental illness, and then later to serious mental illness.
As defined by federal regulation, a serious mental illness is a condition that affects “persons
aged 18 or older who currently or at any time in the past year have had a diagnosable mental,
behavioral, or emotional disorder (excluding developmental and substance use disorders) of
sufficient duration to meet diagnostic criteria specified within DSM-IV (APA, 1994) that has
resulted in serious functional impairment, which substantially interferes with or limits one or
more major life activities” such as maintaining interpersonal relationships, activities of daily
living, self-care, employment, and recreation. (Substance Abuse and Mental Health Services
Administration, 2013, p. 11). This definition has since been amended to also exclude dementias
and mental disorders due to a general medical condition (Substance Abuse and Mental Health
Services Administration, 2006).
The legal definition of serious mental illness is more flexible in that it may 1) vary by state, 2)
include childhood diagnoses, and 3) exclude the necessity of functional impairment. Mental
disorders typically meeting criteria for serious mental illness include schizophrenia,
schizoaffective disorder, psychotic disorders, major depressive disorders, bipolar disorders, and
borderline personality disorder. Anxiety disorders (such as obsessive compulsive disorder and
panic disorder) or eating disorders (such as anorexia nervosa and bulimia nervosa) can also
meet criteria for serious mental illness. Mental disorders causing significant impairment in
children are typically referred to as mental, emotional, and behavioral disorders (O’Connell, Boat, &
Warner, 2009); these should not be confused with serious emotional disturbance , or emotional
disturbance (Mark & Buck, 2006), which specifically refer to disorders affecting academic learning
and achievement.
Many mental health advocates and administrators point out that, although serious mental
illness is most commonly associated with a particular set of disorders such as schizophrenia,
schizoaffective disorder, bipolar disorder, or major depressive disorder; all mental illnesses
Behind the Term: Serious Mental Illness

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 have the potential to produce impairment, interfere with quality of life, or qualify as “serious”
according to the federal usage of the term.
The following is a summary of terms related to serious mental illness that can be used
interchangeably:


affective disorders ≈ mood disorders



bipolar disorders ≈ manic–depressive disorder/manic depression



major depressive disorders ≈ major depression

The following terms are nested within other serious mental illness categories:


affective disorders: depression, bipolar disorder, anxiety disorder



anxiety disorders: panic disorder, obsessive compulsive disorder, posttraumatic stress
disorder
disruptive behavior disorders: conduct disorder, oppositional defiant disorder, attention
deficit hyperactivity disorder
eating disorders: bulimia nervosa, anorexia nervosa





psychotic disorders: schizophrenia, delusional disorder, schizoaffective disorder, bipolar
disorder with psychotic symptoms, depression with psychotic features

References
American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th
ed.). Washington, DC: Author.
Fed. Reg.Vol. 58, No. 96. 29422. (May 20, 1993). Retrieved from
http://www.samhsa.gov/sites/default/files/federal-register-notice-58-96definitions.pdf
Goldman, H.H., & Grob, G.N. (2006). Defining ‘mental illness’ in mental health policy. Health
Affairs, 25(3), 737–749. Retrieved from
http://content.healthaffairs.org/content/25/3/737.full
Mark, T. L., & Buck, J. A. (2006). Characteristics of U.S. youths with serious emotional disturbance:
Data from the National Health Interview Survey. Psychiatric Services, 57(11), 1573–1578.
O'Connell, M. E., Boat, T., & Warner, K. E. (Eds.). (2009). Preventing mental, emotional, and
behavioral disorders among young people: Progress and possibilities. National Academies Press.
Substance Abuse and Mental Health Services Administration (SAMHSA). (2006). Definitions and
terms relating to co-occurring disorders (DHHS Pub. No. [SMA] 06-4163). Rockville, MD:
Author.
Substance Abuse and Mental Health Services Administration (SAMHSA). (2013). Results from the
2012 National Survey on Drug Use and Health: Mental health findings (NSDUH Series H-47,
HHS Publication No. [SMA] 13-4805). Rockville, MD: Author.

Behind the Term: Serious Mental Illness

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