classification of mental disorders classification of mental disorders the classification of mental disorders is also known as psychiatric nosology or psychiatric taxonomy. it represents a key aspect of psychiatry and other mental health professions and is an important issue for people who may be diagnosed. there are currently two widely established systems for classifying mental disorders: chapter v of the tenth international classification of diseases (icd-10) produced by the world health organization (who); the diagnostic and statistical manual of mental disorders (dsm-5) produced by the american psychiatric association (apa). for broader coverage of this topic, see mental disorder. part of a series onpsychology outline history subfields basic types abnormal behavioral behavioral genetics biological cognitive/cognitivism comparative cross-cultural cultural developmental differential evolutionary experimental mathematical neuropsychology personality positive psychodynamic psychometrics quantitative social applied psychology applied behavior analysis clinical community consumer counseling critical educational environmental ergonomics food forensic health humanistic industrial and organizational legal medical military music occupational health political psychometrics religion school sport traffic lists disciplines organizations psychologists psychotherapies research methods theories timeline topics psychology portal both list categories of disorders thought to be distinct types, and have deliberately converged their codes in recent revisions so that the manuals are often broadly comparable, although significant differences remain. other classification schemes may be in use more locally, for example the chinese classification of mental disorders. other manuals have some limited use by those of alternative theoretical persuasions, such as the psychodynamic diagnostic manual. the widely used dsm and icd classifications employ operational definitions. definitions in the scientific and academic literature on the definition or categorization of mental disorders, one extreme argues that it is entirely a matter of value judgments (including of what is normal) while another proposes that it is or could be entirely objective and scientific (including by reference to statistical norms); other views argue that the concept refers to a "fuzzy prototype" that can never be precisely defined, or that the definition will always involve a mixture of scientific facts (e.g. that a natural or evolved function isn't working properly) and value judgments (e.g. that it is harmful or undesired). lay concepts of mental disorder vary considerably across different cultures and countries, and may refer to different sorts of individual and social problems. the who and national surveys report that there is no single consensus on the definition of mental disorder, and that the phrasing used depends on the social, cultural, economic and legal context in different contexts and in different societies. the who reports that there is intense debate about which conditions should be included under the concept of mental disorder; a broad definition can cover mental illness, intellectual disability, personality disorder and substance dependence, but inclusion varies by country and is reported to be a complex and debated issue. there may be a criterion that a condition should not be expected to occur as part of a person's usual culture or religion. however, despite the term "mental", there is not necessarily a clear distinction drawn between mental (dys)functioning and brain (dys)functioning, or indeed between the brain and the rest of the body. most international clinical documents avoid the term "mental illness", preferring the term "mental disorder". however, some use "mental illness" as the main overarching term to encompass mental disorders. some consumer/survivor movement organizations oppose use of the term "mental illness" on the grounds that it supports the dominance of a medical model. the term "serious mental impairment" (smi) is sometimes used to refer to more severe and long-lasting disorders while "mental health problems" may be used as a broader term, or to refer only to milder or more transient issues. confusion often surrounds the ways and contexts in which these terms are used. mental disorders are generally classified separately to neurological disorders, learning disabilities or mental retardation. icd-10 the international classification of diseases (icd) is an international standard diagnostic classification for a wide variety of health conditions. the icd-10 states that mental disorder is "not an exact term", although is generally used "...to imply the existence of a clinically recognisable set of symptoms or behaviours associated in most cases with distress and with interference with personal functions." chapter v focuses on "mental and behavioural disorders" and consists of 10 main groups: f0 - f9: organic, including symptomatic, mental disorders f10 - f-19: mental and behavioural disorders due to use of psychoactive substances f20 - f25: schizophrenia, schizotypal and delusional disorders f30 -f39: mood disorders f40 - f49: neurotic, stress-related and somatoform disorders f50 - f59: behavioural syndromes associated with physiological disturbances and physical factors f60 - f69: disorders of personality and behaviour in adult persons f70 - f79: mental retardation f80 - f89: disorders of psychological development f90 - 98: behavioural and emotional disorders with onset usually occurring in childhood and adolescence in addition, a group of f99 "unspecified mental disorders". within each group there are more specific subcategories. the who has revised icd-10 to produce the latest version of the icd, icd-11 adopted by the 72nd world health assembly in 2019 and came into effect on 1 january 2022. dsm-iv the dsm-iv was originally published in 1994 and listed more than 250 mental disorders. it was produced by the american psychiatric association and it characterizes mental disorder as "a clinically significant behavioral or psychological syndrome or pattern that occurs in an individual,...is associated with present distress...or disability...or with a significantly increased risk of suffering" but that "...no definition adequately specifies precise boundaries for the concept of 'mental disorder'...different situations call for different definitions" (apa, 1994 and 2000). the dsm also states that "there is no assumption that each category of mental disorder is a completely discrete entity with absolute boundaries dividing it from other mental disorders or no mental disorders." the dsm-iv-tr (text revision, 2000) consisted of five axes (domains) on which disorder could be assessed. the five axes were: axis i: clinical disorders (all mental disorders except personality disorders and mental retardation) axis ii: personality disorders and mental retardation axis iii: general medical conditions (must be connected to a mental disorder) axis iv: psychosocial and environmental problems (for example limited social support network) axis v: global assessment of functioning (psychological, social and job-related functions are evaluated on a continuum between mental health and extreme mental disorder) the axis classification system was removed in the dsm-5 and is now mostly of historical significance. the main categories of disorder in the dsm are: dsm groupexamples disorders usually first diagnosed in infancy, childhood or adolescence. *disorders such as adhd and epilepsy have also been referred to as developmental disorders and developmental disabilities.adhd delirium, dementia, and amnesia and other cognitive disordersalzheimer's disease mental disorders due to a general medical conditionaids-related psychosis substance-related disordersalcohol use disorder schizophrenia and other psychotic disordersdelusional disorder mood disordersmajor depressive disorder, bipolar disorder anxiety disordersgeneralized anxiety disorder, social anxiety disorder somatoform disorderssomatization disorder factitious disordersmünchausen syndrome dissociative disordersdissociative identity disorder sexual and gender dysphoriadyspareunia, gender dysphoria eating disordersanorexia nervosa, bulimia nervosa sleep disordersinsomnia impulse control disorders not elsewhere classifiedkleptomania adjustment disordersadjustment disorder personality disordersnarcissistic personality disorder other conditions that may be a focus of clinical attentiontardive dyskinesia, child abuse other schemes the chinese society of psychiatry's chinese classification of mental disorders (currently ccmd-3) the latin american guide for psychiatric diagnosis (gldp). the research domain criteria (rdoc), a framework being developed by the national institute of mental health the hierarchical taxonomy of psychopathology (hitop), developed by the hitop consortium, a group of psychologists and psychiatrists who had a record of scientific contributions to classification of psychopathology. childhood diagnosis child and adolescent psychiatry sometimes uses specific manuals in addition to the dsm and icd. the diagnostic classification of mental health and developmental disorders of infancy and early childhood (dc:0-3) was first published in 1994 by zero to three to classify mental health and developmental disorders in the first four years of life. it has been published in 9 languages. the research diagnostic criteria-preschool age (rdc-pa) was developed between 2000 and 2002 by a task force of independent investigators with the goal of developing clearly specified diagnostic criteria to facilitate research on psychopathology in this age group. the french classification of child and adolescent mental disorders (cftmea), operational since 1983, is the classification of reference for french child psychiatrists. usage the icd and dsm classification schemes have achieved widespread acceptance in psychiatry. a survey of 205 psychiatrists, from 66 countries across all continents, found that icd-10 was more frequently used and more valued in clinical practice and training, while the dsm-iv was more frequently used in clinical practice in the united states and canada, and was more valued for research, with accessibility to either being limited, and usage by other mental health professionals, policy makers, patients and families less clear. . a primary care (e.g. general or family physician) version of the mental disorder section of icd-10 has been developed (icd-10-phc) which has also been used quite extensively internationally. a survey of journal articles indexed in various biomedical databases between 1980 and 2005 indicated that 15,743 referred to the dsm and 3,106 to the icd. in japan, most university hospitals use either the icd or dsm. icd appears to be the somewhat more used for research or academic purposes, while both were used equally for clinical purposes. other traditional psychiatric schemes may also be used. types of classification schemes categorical schemes the classification schemes in common usage are based on separate (but may be overlapping) categories of disorder schemes sometimes termed "neo-kraepelinian" (after the psychiatrist kraepelin) which is intended to be atheoretical with regard to etiology (causation). these classification schemes have achieved some widespread acceptance in psychiatry and other fields, and have generally been found to have improved inter-rater reliability, although routine clinical usage is less clear. questions of validity and utility have been raised, both scientifically and in terms of social, economic and political factors—notably over the inclusion of certain controversial categories, the influence of the pharmaceutical industry, or the stigmatizing effect of being categorized or labelled. non-categorical schemes some approaches to classification do not use categories with single cut-offs separating the ill from the healthy or the abnormal from the normal (a practice sometimes termed "threshold psychiatry" or "dichotomous classification"). classification may instead be based on broader underlying "spectra", where each spectrum links together a range of related categorical diagnoses and nonthreshold symptom patterns. some approaches go further and propose continuously varying dimensions that are not grouped into spectra or categories; each individual simply has a profile of scores across different dimensions. dsm-5 planning committees are currently seeking to establish a research basis for a hybrid dimensional classification of personality disorders. however, the problem with entirely dimensional classifications is they are said to be of limited practical value in clinical practice where yes/no decisions often need to be made, for example whether a person requires treatment, and moreover the rest of medicine is firmly committed to categories, which are assumed to reflect discrete disease entities. while the psychodynamic diagnostic manual has an emphasis on dimensionality and the context of mental problems, it has been structured largely as an adjunct to the categories of the dsm. moreover, dimensionality approach was criticized for its reliance on independent dimensions whereas all systems of behavioral regulations show strong inter-dependence, feedback and contingent relationships descriptive vs somatic descriptive classifications are based almost exclusively on either descriptions of behavior as reported by various observers, such as parents, teachers, and medical personnel; or symptoms as reported by individuals themselves. as such, they are quite subjective, not amenable to verification by third parties, and not readily transferable across chronologic and/or cultural barriers. somatic nosology, on the other hand, is based almost exclusively on the objective histologic and chemical abnormalities which are characteristic of various diseases and can be identified by appropriately trained pathologists. while not all pathologists will agree in all cases, the degree of uniformity allowed is orders of magnitude greater than that enabled by the constantly changing classification embraced by the dsm system. some models, like functional ensemble of temperament suggest to unify nosology of somatic, biologically based individual differences in healthy people (temperament) and their deviations in a form of mental disorders in one taxonomy. cultural differences classification schemes may not apply to all cultures. the dsm is based on predominantly american research studies and has been said to have