How a mental illness is determined and classified

Carol RoachStarred Page By Carol Roach, 26th Feb 2015 | Follow this author | RSS Feed | Short URL
Posted in Wikinut>Health>Mind & Spirit>Mental Health

This article defines mental illness as presented in the various editions of the DSM..


Many people often wonder how a doctor, psychiatrist, and psychologist decide who has what mental illness and why. It is very tricky because many mental illnesses resemble each other.

Extension of behaviors we already have

University professors are often amused as they watch first year psychology students read about the different illnesses and then become convinced they have each and every mental illness they read about.

Why is that?

Mental illness is just an extension of behaviors many humans already exhibit. The first statement about mental illness that can be made is that a mental illness is an exaggeration of the behaviors everyone possesses. The difference between what is considered normal and what is considered abnormal or unhealthy is the degree of that behavior present. This becomes the bottom line for diagnosing mental illness.

Every one of us will get down in the dumps from time to time, but not every one of us will be so down in the dumps that we cannot eat or sleep or do just about anything. We don’t spend our lives in bed staring up at the ceiling or thinking about death or committing suicide. When people get that far down in the dumps it is not considered healthy and they are diagnosed with major depression, which is a serious mental illness.

Having said that, even depression has different levels of severity from mild, to moderate and then severe.

Sub-classifying a mental disorder according to its severity is done quite frequently and that is because different symptoms or severity of symptoms would be exhibited in these sub-divisions.

Labeling people

You may be thinking at this point, what is the big deal, do psychiatrists not have anything better to do with their time than stick labels on people? The answer is, these labels are often necessary to understand what is going on with the person in question and to provide the best possible treatment.

For example, in the case of depression, major depression is treated with antidepressants to restore the chemical balance in the brain. Mild depression can be treated with a good self talk or talk with a friend, and the symptoms often don’t last very long; and moderate depression may require therapy such as cognitive therapy to help the person get back on track.

You would not want to avoid giving medication to someone who has major depression, because frankly all the other therapies would just not work when a person is that deeply depressed. Nor, would you want to give unneeded medication to someone who really doesn’t need it and all they really require is a fresh outlook on life (mild depression). For people who have moderate depression they may need therapy to help them get focused and back on track. Therefore the doctor, psychiatrist, and counselor have to have a standard system to make these classifications.



Standardization is very important; otherwise there is chaos. Even with standardization, there is room for misdiagnosis; therefore imagine without it.

Diagnostic Statistical Manual

The most common diagnostic tool for mental illness used in North America and different degrees around the world, is the Diagnostic Statistical Manual, which was developed by the American Psychiatric Association. This manual is not only used by the medical community, it is used by government drug regulation agencies, policymakers; and pharmaceutical companies.

The legal system also use it. Mental illness will not be accepted in court as a defense or as a claim for benefits from the government or an insurance company, etc., in a lawsuit, without a DSM diagnosis.

Furthermore in the interest of furthering our understanding of mental conditions, clinical studies, which require a certain type of person with a certain mental illness, will rely on the DSM classification to recruit their test subjects.

The DSM is the standard classification system for mental illness and through its history it has received much praise for its level of excellence and perhaps even more controversy for certain conditions listed as mental illness.

For example, homosexuality was listed as a mental disorder in the DSM and was taken out in 1987 and no longer listed as a mental disorder due to the debate on whether or not homosexuality is older classification of mental illness, deviant behavior, or healthy lifestyle choice.

What is the DSM

The DSM was first published in 1952 and many disorders have been added and taken out since then. Some of the modern disorders are the same original disorders, but with new subtypes, and others are the same disorders now carrying an entirely new name. For example, what was once known as Manic Depressive Disorder is now called Bipolar Disorder.

The manual came about as a compilation of medical information and statistical data, and was based on a manual that was produced by the US army
. There have been several revisions since 1952. The last version was the DSM IV published in 1994, with its revised edition the DSM IV-TR in 2000. Altogether there have been five revisions to date. The DSM V is in the works and expected to come out 2012.

International Statistical Classification of Diseases and Related Health Problems

The mental health section of the ICD is also another diagnostic tool that mental health professionals use, mostly in Europe. However, the DSM is most commonly used in North America. The DSM and ICD will try to synchronize coding systems as best they can. It is not always possible because the editions do not come out at the same time. Many psychiatrists across the world will use the ICD for clinical use and the DSM for research use.

History Behind the DSM

The need to collect and compile clinical statistical information first became important in the late 1880’s. In 1840, a single category on the US census was entitled, “idiocy/insanity”. By 1880 there were seven classifications included in the US census which were: mania, monomania, dipsomania, paresis, melancholia, dementia, and epilepsy .

By 1917, the National Committee on Mental Hygiene along with the Committee on Statistics now known the American Psychiatric Association published a new hospital guide called the Statistical Manual for the Use of Institutions for the Insane. At this time there were 22 mental disorders classified.

Standard Classified Nomenclature of Disease was also a classification system used at the time as a subsection in the US Medical Guide. It was referred to as the “Standard”.

Different editions of the book

DSM – I (1952)

The need to recruit mentally stable soldiers during World War II brought the focus away from the medical community and onto the army. In 1943, the Medical 203 was created by a team of psychiatrists and Brigadier General William C. Menninger. There were major revisions from the old “Standard” to conform with more modern day thinking and the Medical 203 was widely used throughout the Armed Forces and The Veterans Association which used a variation of the Medical 203.

By 1949, the World Health Association published a section for mental disorders in the ICD making it the very first time an entire section of mental disorders was included.

By 1950, it was evident there was a clear need to develop a system that was standard rather than having so many classification systems to choose from. The DSM-I relied heavily upon the Medical 203 for its formulation. The medical 203 was a statistical manual compiling the statistical data from the known medical sources of the time. This manual had 130 medical conditions.

DSM –II (1968)

This version was similar to the first one, and now had 182 conditions including Kreapelin’s System of Classification. The Manual was heavily influenced by the psychodynamic theory dominance of the times. The distinction between neurosis (worry and anxiety) and psychosis (out of touch with really, hallucinations and delusions) were clearly made.

The DSM II was widely controversial due to the signs of the times and the changing social values influenced by the work of Alfred Kinsey (doctor; researcher on human sexuality) and Evelyn Hooker (psychologist studying homosexuality). Their concerns focused on the issue of homosexuality being categorized as a mental disorder. By the 7th printing the classification as a mental order was taken out. However, due to the strong influence of psychiatrist Robert Spitizer a new category called Gender Identity Disorder was included.

The differences continued

DSM – III (1980)

Again, the need to maintain standards for diagnostic classification between the European and North American medical community was the focus. Many debates went on as to how mental disorders should be classified and why. The heavy influence on psychodynamic theory was challenged. Some critics wanted to eliminate the term neurosis completely from the manual while others said that it would not be a qualified mental illness standard if if only biological based illnesses were included.

The classification Sexual Orientation Disturbance was changed for Ego-dystonic Homosexuality.

DSM – III-R (1987)

Categories were renamed and classified while others were deleted. The controversial Pre-menstrual Dysphoric Disorder and Masochistic Personality Disorder were deleted. The very controversial Sexual Identity Disorder was taken out, but its presence was still to be found in “Sexual Disorder not otherwise classified. You can say that old habits are slow to die.

DSM –IV (1994)

A major difference in this version was the inclusion of a clinical significance requirement for at least half of their categories. The Illness must produce, “clinically significant distress or impairment in social, occupational, or other important areas of functioning”. As you see, homosexuals who are absolutely happy with their sexuality would not fall under this category of mental illness.

DSM – IV-TR (2000)

DSM – IV-TR (2000) provided more clinical information on the existing mental conditions.

DSM Axes – Axis I has the most severe disorders followed by Axis II

On Axis I you will find the major disorders. They are considered psychological, developmental and learning disorders, such as: Schizophrenia, Bipolar Disorder, depression, phobias, autism, and ADHD.

On Axis II you will have the personality disorders such as: Borderline Personality Disorder, Paranoid Personality Disorder, Schizoid Personality Disorder, Schizotypal Personality Disorder, Antisocial Personality Disorder, Narcissistic Personality Disorder, Histrionic Personality Disorder, Obsessive Compulsive Personality Disorder, and mental retardation.

On Axis III you will find brain injuries and other physical conditions, which can affect brain functioning.

On Axis IV you will find psychosocial and environment factors that contribute to a disorder

On Axis V you will find the Global Assessment of Functioning, or Global Assessment Scale for children under 18.

Some of the changes in the DSM V

Neurodevelopmental Disorders
Intellectual Disability (Intellectual Developmental Disorder)

The word mental retardation was changed to mental intellectual disability. "The term intellectual developmental disorder was placed in parentheses to reflect the
World Health Organization’s classification system, which lists “disorders” in the International Classification of Diseases (ICD; ICD-11 to be released in 2015) and bases all “disabilities” on the International Classification of Functioning, Disability, and Health (ICF). Because the ICD-11 will not be adopted for several years, intellectual disability was chosen as the current preferred term with the bridge term for the future in parentheses".


Some of the changes in the DSM V

The latest DSM V was published on May 18, 2013. It changed some requirements for schizophrenia and Post Traumatic Stress Disorder.

Neurodevelopmental Disorders
Intellectual Disability (Intellectual Developmental Disorder)

The word mental retardation was changed to mental intellectual disability. "The term intellectual developmental disorder was placed in parentheses to reflect the
World Health Organization’s classification system, which lists “disorders” in the International Classification of Diseases (ICD; ICD-11 to be released in 2015) and bases all “disabilities” on the International Classification of Functioning, Disability, and Health (ICF). Because the ICD-11 will not be adopted for several years, intellectual disability was chosen as the current preferred term with the bridge term for the future in parentheses".

Communication disorders

"The DSM-5 communication disorders include language disorder (which combines DSM-IV expressive and mixed receptive-expressive language disorders), speech sound disorder (a new name for phonological disorder), and childhood-onset fluency disorder (a new name for stuttering). Also included is social (pragmatic) communication disorder, a new condition for persistent difficulties in the social uses of verbal and nonverbal communication."

Autism Spectrum Disorder
Now the four autism disorders are no longer separated but included as one disorder.

The changes presented here are far from complete and the interested reader is encouraged to view the above mentioned site to read more about it.

The manual was criticized before it was even published.. "Various scientists have argued that the DSM-5 forces clinicians to make distinctions that are not supported by solid evidence, distinctions that have major treatment implications, including drug prescriptions and the availability of health insurance coverage. General criticism of the DSM-5 ultimately resulted in a petition signed by 13,000, and sponsored by many mental health organizations, which called for outside review of the document."

All photos taken from the public domain

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Aspergers, Dsm V, History Of The Dsm, How Is A Mental Illness Defined, Mental Illness, Schizophrenia, Who Decides What Is A Mental Illness

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author avatar Carol Roach
Retired therapist and author of two books, freelance writer, newsletter editor, and blogger. I write, health, mental health, women's issues, animal , celebrity, history, and SEO articles.

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author avatar Retired
26th Feb 2015 (#)

Informative and well-researched.

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author avatar Judy Ellen
26th Feb 2015 (#)

This is very valuable information to consider and I am glad to know that our little quirks and differences are not a sign of mental illness but just those little unique and sometimes even humorous qualities that make us human! God Bless!!

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author avatar spirited
27th Feb 2015 (#)

Thanks for this Carol.

We are all different too I guess, and a mild depression for some might be a severe depression in others, is that true?

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author avatar Carol Roach
27th Feb 2015 (#)

No there is a difference between mild, moderate, or severe and you will have one of them, but mild is always mild, and moderate is always moderate, and severe is always severe. Think of it as a dress size to make it easier. You are either a size 8, or a size 12, or a size 18 although all these sizes exist you only wear one size.

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