The definition and classification of mental disorder is a key issue for the mental health professions and for users and providers of mental health services. Most international clinical documents use the term "mental disorder" rather than "mental illness". There is no single definition and the inclusion criteria are said to vary depending on the social, legal and political context. In general, however, a mental disorder has been characterized as a clinically significant behavioral or psychological pattern that occurs in an individual and is usually associated with distress, disability or increased risk of suffering. The term "serious mental illness" (SMI) is sometimes used to refer to more severe and long-lasting disorder. A broad definition can cover mental disorder, mental retardation, personality disorder and substance dependence. The phrase "mental health problems" may be used to refer only to milder or more transient issues. There is often a criterion that a condition should not be expected to occur as part of a person's usual culture or religion. Nevertheless, the term "mental" is not necessarily used to imply a distinction between mental (dys)functioning and brain (dys)functioning, or indeed between the brain and the rest of the body.
There are currently two widely established systems that classify mental disorders - Chapter V of the International Classification of Diseases (ICD-10), produced by the World Health Organization (WHO), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) produced by the American Psychiatric Association (APA). Both list categories of disorder and provide standardized criteria for diagnosis. They 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 may be used by those of alternative theoretical persuasions, for example the Psychodynamic Diagnostic Manual.
Some approaches to classification do not employ distinct categories based on cut-offs separating the abnormal from the normal. They are variously referred to as spectrum, continuum or dimensional systems. There is a significant scientific debate about the relative merits of a categorical or a non-categorical system. There is also significant controversy about the role of science and values in classification schemes, and about the professional, legal and social uses to which they are put.
The state of anxiety or fear can become disordered, so that it is unusually intense or generalized over a prolonged period of time. Commonly recognized categories of anxiety disorders include specific phobia, Generalized anxiety disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia, Obsessive-Compulsive Disorder, Post-traumatic stress disorder. Relatively long lasting affective states can also become disordered. Mood disorder involving unusually intense and sustained sadness, melancholia or despair is know as Clinical depression (or Major depression), and may more generally be described as Emotional dysregulation. Milder but prolonged depression can be diagnosed as dysthymia. Bipolar disorder involves abnormally "high" or pressured mood states, known as mania or hypomania, alternating with normal or depressed mood. Whether unipolar and bipolar mood phenomena represent distinct categories of disorder, or whether they usually mix and merge together along a dimension or spectrum of mood, is under debate in the scientific literature.
Patterns of belief, language use and perception can become disordered. Psychotic disorders centrally involving this domain include Schizophrenia and Delusional disorder. Schizoaffective disorder is a category used for individuals showing aspects of both schizophrenia and affective disorders. Schizotypy is a category used for individuals showing some of the traits associated with schizophrenia but without meeting cut-off criteria.
The fundamental characteristics of a person that influence his or her cognitions, motivations, and behaviors across situations and time - can be seen as disordered due to being abnormally rigid and maladaptive. Categorical schemes list a number of different personality disorders, such as those classed as eccentric (e.g. Paranoid personality disorder, Schizoid personality disorder, Schizotypal personality disorder), those described as dramatic or emotional (Antisocial personality disorder, Borderline personality disorder, Histrionic personality disorder, Narcissistic personality disorder) or those seen as fear-related (Avoidant personality disorder, Dependent personality disorder, Obsessive-compulsive personality disorder).
There may be an emerging consensus that personality disorders, like personality traits in the normal range, incorporate a mixture of more acute dysfunctional behaviors that resolve in relatively short periods, and maladaptive temperamental traits that are relatively more stable. Non-categorical schemes may rate individuals via a profile across different dimensions of personality that are not seen as cut off from normal personality variation, commonly through schemes based on the Big Five personality traits.
Other disorders may involve other attributes of human functioning. Eating practices can be disordered, at least in relatively rich industrialized areas, with either compulsive over-eating or under-eating or binging. Categories of disorder in this area include Anorexia nervosa, Bulimia nervosa, Exercise Bulimia or Binge eating disorder. Sleep disorders such as Insomnia also exist and can disrupt normal sleep patterns. Sexual and gender identity disorders, such as Dyspareunia or Gender identity disorder or ego-dystonic homosexuality. People who are abnormally unable to resist urges, or impulses, to perform acts that could be harmful to themselves or others, may be classed as having an impulse control disorder, including various kinds of Tic disorders such as Tourette's Syndrome, and disorders such as Kleptomania (stealing) or Pyromania (fire-setting). Substance-use disorders include Substance abuse disorder. Addictive gambling may be classed as a disorder. Inability to sufficiently adjust to life circumstances may be classed as an Adjustment disorder. The category of adjustment disorder is usually reserved for problems beginning within three months of the event or situation and ending within six months after the stressor stops or is eliminated. People who suffer severe disturbances of their self-identity, memory and general awareness of themselves and their surroundings may be classed as having a Dissociative identity disorder, such as Depersonalization disorder or Dissociative Identify Disorder itself (which has also been called multiple personality disorder, or "split personality".). Factitious disorders, such as Munchausen syndrome, also exist where symptoms are experienced and/or reported for personal gain.
Disorders appearing to originate in the body, but thought to be mental, are known as somatoform disorders, including Somatization disorder. There are also disorders of the perception of the body, including Body dysmorphic disorder. Neurasthenia is a category involving somatic complaints as well as fatigue and low spirits/depression, which is officially recognized by the ICD-10 but not by the DSM-IV. Memory or cognitive disorders, such as amnesia or Alzheimer's disease exist.
Some disorders are thought to usually first occur in the context of early childhood development, although they may continue into adulthood. The category of Specific developmental disorder may be used to refer to circumscribed patterns of disorder in particular learning skills, motor skills, or communication skills. Disorders which appear more generalized may be classed as pervasive developmental disorders (PDD) also known as autism spectrum disorders (ASD); these include autism, Asperger's, Rett syndrome, childhood disintegrative disorder and other types of PDD whose exact diagnosis may not be specified. Other disorders mainly or first occurring in childhood include Reactive attachment disorder; Separation Anxiety Disorder; Oppositional Defiant Disorder; Attention Deficit Hyperactivity Disorder.
Other proposed disorders include: Self-defeating personality disorder, Sadistic personality disorder, Passive-aggressive personality disorder, Premenstrual dysphoric disorder, Video game addiction or Internet addiction disorder.
Genetic studies have indicated that genes often play an important role in the development of mental disorders, via developmental pathways interacting with environmental factors. The reliable identification of connections between specific genes and specific categories of disorder has proven more difficult.
Environmental events surrounding pregnancy and birth have also been implicated. Traumatic brain injury may increase the risk of developing certain mental disorders. There have been some tentative inconsistent links found to certain viral infections, to substance misuse, and to general physical health.
Abnormal functioning of neurotransmitter systems has been implicated, including serotonin, norepinephrine, dopamine and glutamate systems. Differences have also been found in the size or activity of certain brains regions in some cases. Psychological mechanisms have also been implicated, such as cognitive and emotional processes, personality, temperament and coping style.
Social influences have been found to be important, including abuse, bullying and other negative or stressful life experiences. The specific risks and pathways to particular disorders are less clear, however. Aspects of the wider community have also been implicated, including employment problems, socioeconomic inequality, lack of social cohesion, problems linked to migration, and features of particular societies and cultures.
Cultural processes can affect which behaviors are considered clinically relevant and how they are framed. The DSM has been said to have a Euro-American outlook, such that differing disorders or concepts from other countries or non-mainstream cultures are neglected or misrepresented; while the latter are described as "culture-bound syndromes", Western cultural phenomena are taken as universals. The fact that diagnostic criteria sets are acceptable to or applied reliably across different cultures does not necessarily make the constructs themselves valid within those cultures, as this can be statistically achieved through an entirely illusory diagnostic construct. On the other hand, it is argued that if a diagnostic category is valid then cross-cultural factors are irrelevant, or only affect how symptoms are manifested.
Cultural variation can suggest that the very construct of "mental disorder" is in fact culture-bound. Different societies, cultures, and even persons within a particular culture may disagree as to what constitutes optimal or pathological biological and psychological functioning, and indeed research has demonstrated variation across cultures in the relative importance placed on, for example, happiness, autonomy, or social relationships for pleasure. Likewise, the fact that a behavior pattern is valued, accepted, encouraged, or even statistically normative within a particular culture does not necessarily mean it is conducive to optimal psychological functioning. There may be a tendency to overstate or misinterpret neurophysiological findings and to understate the scientific importance of social-psychological variables, and the cultural and ethnic diversity of individuals is often discounted by researchers and services providers. Rather than indicating a disorder from within, distress and disability may be seen as an indicator of emotional struggle and the need to address social and structural problems and some academics and clinicians have advocated a postmodernist conceptualization of mental distress and wellbeing and "heretical" psychologies centered on alternative cultural and ethnic identities and experiences.
Treatment and support may be provided in psychiatric hospitals, clinics or any of a diverse range of community mental health services. Often an individual may engage in different treatment modalities. Individuals may be treated against their will in some cases. Services in some countries are increasingly based on a Recovery model that supports an individual's personal journey to regain a meaningful life.
Psychoeducation may be used to provide people with the information to understand and manage their problems. Creative therapies are sometimes used, including music therapy, art therapy or drama therapy. Lifestyle adjustments and supportive measures are often used, including peer support, self-help groups for mental health and supported housing or supported employment (including social firms). Some advocate dietary supplements. Many things have been found to help at least some people. A placebo effect may play a role in any intervention.
Even those disorders often considered the most serious and intractable have varied courses. Long-term international studies of schizophrenia have found that over a half of individuals recover in terms of symptoms, and around a fifth to a third in terms of symptoms and functioning, with some requiring no medication. At the same time, many have serious difficulties and support needs for many years, although "late" recovery is still possible. The WHO concluded that the findings joined others in "relieving patients, carers and clinicians of the chronicity paradigm which dominated thinking throughout much of the 20th century. Around half of people initially diagnosed with bipolar disorder achieve syndromal recovery (no longer meeting criteria for the diagnosis) within six weeks, and nearly all achieve it within two years, with nearly a half regaining their prior occupational and residential status in that period. However, nearly a half go on to experience a new episode of mania or major depression within the next two years. Functioning has been found to vary, being poor during periods of major depression or mania but otherwise fair to good, and possibly superior during periods of hypomania in Bipolar II.
Despite often being characterized in purely negative terms, some mental states labeled as disorders can also involve above-average creativity, non-conformity, goal-striving, meticulousness, or empathy. In addition, the public perception of the level of disability associated with mental disorders can change.
Mental disorders have been found to be relatively common, with more than one in three people in most countries reporting sufficient criteria for at least one diagnosis at some point in their life up to the time they were assessed. A new WHO global survey currently underway indicates that anxiety disorders are the most common in all but 1 country, followed by mood disorders in all but 2 countries, while substance disorders and impulse-control disorders were consistently less prevalent. Rates varied by region. Such statistics are widely believed to be underestimates, due to poor diagnosis (especially in countries without affordable access to mental health services) and low reporting rates, in part because of the predominant use of self-report data rather than semi-structured instruments. Actual lifetime prevalence rates for mental disorders are estimated to be between 65% and 85%.
A review of anxiety disorder surveys in different countries found average lifetime prevalence estimates of 16.6%, with women having higher rates on average. A review of mood disorder surveys in different countries found lifetime rates of 6.7% for major depressive disorder (higher in some studies, and in women) and 0.8% for bipolar 1 disorder.
The updated US National Comorbidity Survey (NCS) reported that nearly half of Americans (46.4%) meet criteria at some point in their life for either an anxiety disorder (28.8%), mood disorder (20.8%), impulse-control disorder (24.8%) or substance use disorder (14.6%).
A 2004 cross-Europe study found that approximately one in four people reported meeting criteria at some point in their life for at least one of the DSM-IV disorders assessed, which included mood disorders (13.9%), anxiety disorders (13.6%) or alcohol disorder (5.2%). Approximately one in ten met criteria within a 12-month period. Women and younger people of either gender showed more cases of disorder. A 2005 review of surveys in 16 European countries found that 27% of adult Europeans are affected by at least one mental disorder in a 12 month period.
An international review of studies on the prevalence of schizophrenia found an average (median) figure of 0.4% for lifetime prevalence; it was consistently lower in poorer countries.
Studies of the prevalence of personality disorders (PDs) have been fewer and smaller-scale, but one broad Norwegian survey found a five-year prevalence of almost 1 in 7 (13.4%). Rates for specific disorders ranged from 0.8% to 2.8%, differing across countries, and by gender, educational level and other factors. A US survey that incidentally screened for personality disorder found a rate of 14.79%.
Approximately 7% of a preschool pediatric sample were given a psychiatric diagnosis in one clinical study, and approximately 10% of 1- and 2-year-olds receiving developmental screening have been assessed as having significant emotional/behavioral problems based on parent and pediatrician reports.
A number of professions have developed that specialise in the treatment of mental disorders, including the medical speciality of psychiatry (including psychiatric nursing), the division of psychology known as clinical psychology, Social Work, as well as Mental Health Counselors, Marriage and Family Therapists, Psychotherapists, Counselors and Public Health professionals. Those with personal experience of using mental health services are also increasingly involved in researching and delivering mental health services and working as mental health professionals. The different clinical and scientific perspectives draw on diverse fields of research and theory, and different disciplines may favor differing models, explanations and goals.
The Consumer/Survivor Movement (also known as user/survivor movement) is made up of individuals (and organizations representing them) who are clients of mental health services or who consider themselves "survivors" of mental health services. The movement campaigns for improved mental health services and for more involvement and empowerment within mental health services, policies and wider society. Patient advocacy organizations have expanded with increasing deinstitutionalization in developed countries, working to challenge the stereotypes, stigma and exclusion associated with psychiatric conditions. An antipsychiatry movement fundamentally challenges mainstream psychiatric theory and practice, including the reality or utility of psychiatric diagnoses of mental illnesses.
All human-rights oriented mental health laws require proof of the presence of a mental disorder as defined by internationally accepted standards, but the type and severity of disorder that counts can vary in different jurisdictions. The two most often utilized grounds for involuntary admission are said to be serious likelihood of immediate or imminent danger to self or others, and the need for treatment. Applications for someone to be involuntarily admitted may usually come from a mental health practitioner, a family member, a close relative, or a guardian. Human-rights-oriented laws usually stipulate that independent medical practitioners or other accredited mental health practitioners must examine the patient separately and that there should be regular, time-bound review by an independent review body. An individual must be shown to lack the capacity to give or withhold informed consent (i.e. to understand treatment information and its implications). Legal challenges in some areas have resulted in supreme court decisions that a person does NOT have to agree with a psychiatrist's characterization of their issues as an "illness", nor with a psychiatrist's conviction in medication, but only recognise the issues and the information about treatment options.
Proxy consent (also known as substituted decision-making) may be given to a personal representative, a family member or a legally appointed guardian, or patients may have been able to enact an advance directive as to how they wish to be treated. The right to supported decision-making may also be included in legislation. Involuntary treatment laws are increasingly extended to those living in the community, for example outpatient commitment laws (known by different names) are used in New Zealand, Australia, United Kingdom and most of the United States.
The World Health Organization reports that in many instances national mental health legislation takes away the rights of persons with mental disorders rather than protecting rights, and is often outdated. In 1991, the United Nations adopted the Principles for the Protection of Persons with Mental Illness and the Improvement of Mental Health Care, which established minimum human rights standards of practice in the mental health field. In 2006 the UN formally agreed the Convention on the Rights of Persons with Disabilities to protect and enhance the rights and opportunities of disabled people, including those with psychosocial disabilities
The social stigma associated with mental disorders is a widespread problem. Some people believe those with serious mental illnesses cannot recover, or are to blame for problems. The US Surgeon General stated in 1999 that: "Powerful and pervasive, stigma prevents people from acknowledging their own mental health problems, much less disclosing them to others. Employment discrimination is reported to play a significant part in the high rate of unemployment among those with a diagnosis of mental illness.
Efforts are being undertaken worldwide to eliminate the stigma of mental illness Their methods and outcomes have sometimes been criticized as counterproductive.
Media coverage of mental illness comprises predominantly negative depictions, for example, of incompetence, violence or criminality, with far less coverage of positive issues such as accomplishments or human rights issues. Such negative depictions, including in children's cartoons, are thought to contribute to stigma and negative attitudes in the public and in those with mental health problems themselves, although more sensitive or serious cinematic portrayals have increased in prevalence.
In the United States, The Carter Center has created fellowships for journalists in South Africa, the U.S., and Romania, to enable reporters to research and write stories on mental health topics. Former U.S. First Lady Rosalynn Carter began the fellowships not only to train reporters in how to sensitively and accurately discuss mental health and mental illness, but also to increase the number of stories on these topics in the news media.
The general public have been found to hold a strong stereotype of dangerousness and desire for social distance from individuals described as mentally ill.
However, fear of unpredictable violent acts by people with mental illness is also common. One US national survey indicated that a far higher percentage of Americans rated individuals described as displaying the characteristics of a mental disorder (for example Schizophrenia or Substance Use Disorder) as "likely to do something violent to others" compared to those described as being 'troubled'. Research indicates, on balance, a higher than average number of violent acts by some individuals with certain diagnoses, notably antisocial or psychopathic personality disorders, but conflicting findings about specific symptoms (for example links between psychosis and violence in community settings) - but the mediating factors of such acts are most consistently found to be mainly socio-demographic and socio-economic factors such as being young, male, of lower socio-economic status and, in particular, substance abuse (including alcohol). For the most serious crimes, such as homicide, some diagnoses are over-represented in arrests/convictions; however, although high-profile cases have lead to fears that this has increased due to deinstitutionalization, this does not reflect the evidence.
Violence related to mental disorder typically occurs in the context of complex social interactions, often in a family setting rather than between straingers. It is also an issue in healthcare settings and the wider community.
The risk of anthropomorphism is often raised with regard to such comparisons, and assessment of non-human animals cannot incorporate evidence from linguistic communication. However, available evidence may range from nonverbal behaviors - including physiological responses and homologous facial displays and acoustic utterances - to neurochemical studies. It is pointed out that human psychiatric classification is often based on statistical description and judgement of behaviors (especially when speech or language is impaired) and that the use of verbal self-report is itself problematic and unreliable.
Psychopathology has generally been traced, at least in captivity, to adverse rearing conditions such as early separation of infants from mothers; early sensory deprivation; and extended periods of social isolation. Studies have also indicated individual variation in temperament, such as sociability or impulsiveness. Particular causes of problems in captivity have included integration of strangers in to existing groups and a lack of individual space, in which context some pathological behaviors have also been seen as coping mechanisms. Remedial interventions have included careful individually-tailored re-socialization programs, behavior therapy, environment enrichment, and on rare occasions psychiatric drugs. Socialization has been found to work 90% of the time in disturbed chimpanzees, although restoration of functional sexuality and care-giving is often not achieved.
Laboratory researchers sometimes try to induce symptoms in animals through genetic, neurological or behavioral manipulation, although this has been criticized on empirical grounds and opposed on animal rights grounds. The modern city, in connection with the psychological disorders of its residents, has been described as a human zoo.