Dissociative disorders

Dissociative Disorders 

Definition

The dissociative disorders are a group of mental disorders that affect consciousness defined as causing significant interference with the patient's general functioning, including social relationships and employment.

Description

In order to have a clear picture of these disorders, dissociation should first be understood. Dissociation is a mechanism that allows the mind to separate or compartmentalize certain memories or thoughts from normal consciousness. These split-off mental contents are not erased. They may resurface spontaneously or be triggered by objects or events in the person's environment.

Dissociation is a process that occurs along a spectrum of severity. It does not necessarily mean that a person has a dissociative disorder or other mental illness. A mild degree of dissociation occurs with some physical stressors; people who have gone without sleep for a long period of time, have had "laughing gas" for dental surgery, or have been in a minor accident often have brief dissociative experiences. Another commonplace example of dissociation is a person becoming involved in a book or movie so completely that the surroundings or the passage of time are not noticed. Another example might be driving on the highway and taking several exits without noticing or remembering. Dissociation is related to hypnosis in that hypnotic trance also involves a temporarily altered state of consciousness. Most patients with dissociative disorders are highly hypnotizable.

People in other cultures sometimes have dissociative experiences in the course of religious (in certain trance states) or other group activities. These occurrences should not be judged in terms of what is considered "normal" in the United States.

Moderate or severe forms of dissociation are caused by such traumatic experiences as childhood abuse, combat, criminal attacks, brainwashing in hostage situations, or involvement in a natural or transportation disaster. Patients with acute stress disorder, post-traumatic stress disorder (PTSD), or conversion disorder and somatization disorder may develop dissociative symptoms. Recent studies of trauma indicate that the human brain stores traumatic memories in a different way than normal memories. Traumatic memories are not processed or integrated into a person's ongoing life in the same fashion as normal memories. Instead they are dissociated, or "split off," and may erupt into consciousness from time to time without warning. The affected person cannot control or "edit" these memories. Over a period of time, these two sets of memories, the normal and the traumatic, may coexist as parallel sets without being combined or blended. In extreme cases, different sets of dissociated memories may alter subpersonalities of patients with dissociative identity disorder (multiple personality disorder).

The dissociative disorders vary in their severity and the suddenness of onset. It is difficult to give statistics for their frequency in the United States because they are a relatively new category and are often misdiagnosed. Criteria for diagnosis require significant impairment in social or vocational functioning.

Dissociative amnesia

Dissociative amnesia is a disorder in which the distinctive feature is the patient's inability to remember important personal information to a degree that cannot be explained by normal forgetfulness. In many cases, it is a reaction to a traumatic accident or witnessing a violent crime. Patients with dissociative amnesia may develop depersonalization or trance states as part of the disorder, but they do not experience a change in identity.

Dissociative fugue

Dissociative fugue is a disorder in which a person temporarily loses his or her sense of personal identity and travels to another location where he or she may assume a new identity. Again, this condition usually follows a major stressor or trauma. Apart from inability to recall their past or personal information, patients with dissociative fugue do not behave strangely or appear disturbed to others. Cases of dissociative fugue are more common in wartime or in communities disrupted by a natural disaster.

Depersonalization disorder

Depersonalization disorder is a disturbance in which the patient's primary symptom is a sense of detachment from the self. Depersonalization as a symptom (not as a disorder) is quite common in college-age populations. It is often associated with sleep deprivation or "recreational" drug use. It may be accompanied by "derealization" (where objects in an environment appear altered). Patients sometimes describe depersonalization as feeling like a robot or watching themselves from the outside. Depersonalization disorder may also involve feelings of numbness or loss of emotional "aliveness."

Dissociative identity disorder (did)

Dissociative identity disorder (DID) is the newer name for multiple personality disorder (MPD). DID is considered the most severe dissociative disorder and involves all of the major dissociative symptoms.

Dissociative disorder not otherwise specified (ddnos)

DDNOS is a diagnostic category ascribed to patients with dissociative symptoms that do not meet the full criteria for a specific dissociative disorder.

Causes and symptoms

The moderate to severe dissociation that occurs in patients with dissociative disorders is understood to result from a set of causes:

• an innate ability to dissociate easily
• repeated episodes of severe physical or sexual abuse in childhood
• the lack of a supportive or comforting person to counteract abusive relative(s)
• the influence of other relatives with dissociative symptoms or disorders

The relationship of dissociative disorders to childhood abuse has led to intense controversy and lawsuits concerning the accuracy of childhood memories. The brain's storage, retrieval, and interpretation of memories are still not fully understood. Controversy also exists regarding how much individuals presenting dissociative disorders have been influenced by books and movies to describe a certain set of symptoms (scripting).

The major dissociative symptoms are:

Amnesia

Amnesia in a dissociative disorder is marked by gaps in a patient's memory for long periods of time or for traumatic events. Doctors can distinguish this type of amnesia from loss of memory caused by head injuries or drug intoxication, because the amnesia is "spotty" and related to highly charged events and feelings.

Depersonalization

Depersonalization is a dissociative symptom in which the patient feels that his or her body is unreal, is changing, or is dissolving. Some patients experience depersonalization as being outside their bodies or watching a movie of themselves.

Derealization

Derealization is a dissociative symptom in which the external environment is perceived as unreal. The patient may see walls, buildings, or other objects as changing in shape, size, or color. In some cases, the patient may feel that other persons are machines or robots, though the patient is able to acknowledge the unreality of this feeling.

Identity disturbances

Patients with dissociative fugue, DDNOS, or DID often experience confusion about their identities or even assume new identities. Identity disturbances result from the patient having split off entire personality traits or characteristics as well as memories. When a stressful or traumatic experience triggers the reemergence of these dissociated parts, the patient may act differently, answer to a different name, or appear confused by his or her surroundings.

Diagnosis

When a doctor is evaluating a patient with dissociative symptoms, he or she will first rule out physical conditions that sometimes produce amnesia, depersonalization, or derealization. These physical conditions include epilepsy, head injuries, brain disease, side effects of medications, substance abuse, intoxication, AIDS, dementia complex, or recent periods of extreme physical stress and sleeplessness. In some cases, the doctor may give the patient an electroencephalogram (EEG) to exclude epilepsy or other seizure disorders.

If the patient appears to be physically normal, the doctor will rule out psychotic disturbances, including schizophrenia. In addition, doctors can use some psychological tests to narrow the diagnosis. One is a screener, the Dissociative Experiences Scale (DES). If the patient has a high score on this test, he or she can be evaluated further with the Dissociative Disorders Interview Schedule (DDIS) or the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). It is also possible for doctors to measure a patient's hypnotizability as part of a diagnostic evaluation.

Treatment

Treatment of the dissociative disorders often combines several methods.

Psychotherapy

Patients with dissociative disorders often require treatment by a therapist with some specialized understanding of dissociation. This background is particularly important if the patient's symptoms include identity problems. Many patients with dissociative disorders are helped by group as well as individual treatment.

Medications

Some doctors will prescribe tranquilizers or anti-depressants for the anxiety and/or depression that often accompany dissociative disorders. Patients with dissociative disorders are, however, at risk for abusing or becoming dependent on medications. As of 2001, there is no drug that can reliably counteract dissociation itself.

Hypnosis

Hypnosis is frequently recommended as a method of treatment for dissociative disorders, partly because hypnosis is related to the process of dissociation. Hypnosis may help patients recover repressed ideas and memories. Therapists treating patients with DID sometimes use hypnosis in the process of "fusing" the patient's alternate personalities.

Prognosis

Prognoses for dissociative disorders vary. Recovery from dissociative fugue is usually rapid. Dissociative amnesia may resolve quickly, but can become a chronic disorder in some patients. Depersonalization disorder, DDNOS, and DID are usually chronic conditions. DID usually requires five or more years of treatment for recovery.

Key terms

Amnesia — A general medical term for loss of memory that is not due to ordinary forgetfulness. Amnesia can be caused by head injuries, brain disease, or epilepsy, as well as by dissociation.

Depersonalization — A dissociative symptom in which the patient feels that his or her body is unreal, is changing, or is dissolving.

Derealization — A dissociative symptom in which the external environment is perceived as unreal.

Dissociation — A psychological mechanism that allows the mind to split off traumatic memories or disturbing ideas from conscious awareness.

Fugue — A dissociative experience during which a person travels away from home, has amnesia for their past, and may be confused about their identity but otherwise appear normal.

Hypnosis — The means by which a state of extreme relaxation and suggestibility is induced: used to treat amnesia and identity disturbances that occur in dissociative disorders.

Multiple personality disorder (MPD) — An older term for dissociative identity disorder (DID).

Trauma — A disastrous or life-threatening event that can cause severe emotional distress, including dissociative symptoms and disorders.

Prevention

Since the primary cause of dissociative disorders is thought to involve extended periods of humanly inflicted trauma, prevention depends on the elimination of child abuse and psychological abuse of adult prisoners or hostages.

Resources

Books

Eisendrath, Stuart J. "Psychiatric Disorders." In Current Medical Diagnosis and Treatment, 1998, edited by Stephen McPhee, et al., 37th ed. Stamford: Appleton & Lange, 1997.

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disorder /dis·or·der/ (dis-or´der) a derangement or abnormality of function; a morbid physical or mental state.

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acute stress disorder  an anxiety disorder characterized by development of anxiety, dissociative, and other symptoms within one month following exposure to an extremely traumatic event. If persistent, it may become posttraumatic stress disorder.

adjustment disorder  maladaptive reaction to identifiable stress (e.g., divorce, illness), which is assumed to remit when the stress ceases or when the patient adapts.

affective disorders  mood d's.

amnestic disorders  mental disorders characterized by acquired impairment in the ability to learn and recall new information, sometimes accompanied by inability to recall previously learned information.

anxiety disorders  mental disorders in which anxiety and avoidance behavior predominate, i.e., panic disorder, agoraphobia, social phobia, specific phobia, obsessive-compulsive disorder, posttraumatic stress disorder, acute stress disorder, generalized anxiety disorder, and substance-induced anxiety disorder.

attention-deficit/hyperactivity disorder  a controversial childhood mental disorder with onset before age seven, and characterized by inattention (e.g., distractibility, forgetfulness, not appearing to listen), by hyperactivity and impulsivity (e.g., restlessness, excessive running or climbing, excessive talking, and other disruptive behavior), or by a combination of both types of behavior.

autistic disorder  autism; a severe pervasive developmental disorder with onset usually before three years of age and a biological basis; it is characterized by qualitative impairment in reciprocal social interaction, verbal and nonverbal communication, and capacity for symbolic play, by restricted and unusual repertoire of activities and interests, and often by cognitive impairment.

behavior disorder  conduct d.

binge-eating disorder  an eating disorder characterized by repeated episodes of binge eating, as in bulimia nervosa, but not followed by inappropriate compensatory behavior such as purging, fasting, or excessive exercise.

bipolar disorders  mood disorders with a history of manic, mixed, or hypomanic episodes, usually with present or previous history of one or more major depressive episodes; included are bipolar I d., characterized by one or more manic or mixed episodes, bipolar II d., characterized by one or more hypomanic episodes but no manic episodes, and cyclothymic disorder. The term is sometimes used in the singular to denote either bipolar I disorder, bipolar II disorder, or both.

body dysmorphic disorder  a somatoform disorder characterized by a normal-looking person's preoccupation with an imagined defect in appearance.

breathing-related sleep disorder  any of several disorders characterized by sleep disruption due to some sleep-related breathing problem, resulting in excessive sleepiness or insomnia.

brief psychotic disorder  an episode of psychotic symptoms with sudden onset, lasting less than one month.

catatonic disorder  catatonia due to the physiological effects of a general medical condition and neither better accounted for by another mental disorder nor occurring exclusively during delirium.

character disorders  personality d's.

childhood disintegrative disorder  pervasive developmental disorder characterized by marked regression in various developmental skills, including language, play, and social and motor skills, after two to ten years of initial normal development.

circadian rhythm sleep disorder  a lack of synchrony between the schedule of sleeping and waking required by the external environment and that of a person's own circadian rhythm.

collagen disorder  an inborn error of metabolism involving abnormal structure or metabolism of collagen, e.g., Marfan syndrome, cutis laxa. Cf. collagen disease.

communication disorders  mental disorders characterized by difficulties with speech or language, severe enough to interfere academically, occupationally, or socially.

conduct disorder  a type of disruptive behavior disorder of childhood and adolescence marked by persistent violation of the rights of others or of age-appropriate societal norms or rules.

conversion disorder  a somatoform disorder characterized by conversion symptoms (loss or alteration of voluntary motor or sensory functioning suggesting physical illness) with no physiological basis and not produced intentionally or feigned; a psychological basis is suggested by exacerbation of symptoms during psychological stress, relief from tension (primary gain), or gain of outside support or attention (secondary gains).

cyclothymic disorder  a mood disorder characterized by alternating cycles of hypomanic and depressive periods with symptoms like those of manic and major depressive episodes but of lesser severity.

delusional disorder  a mental disorder marked by well-organized, logically consistent delusions of grandeur, persecution, or jealousy, with no other psychotic feature. There are six types: persecutory, jealous, erotomanic, somatic, grandiose, and mixed.

depersonalization disorder  a dissociative disorder characterized by intense, prolonged, or otherwise troubling feelings of detachment from one's body or thoughts, not secondary to another mental disorder.

depressive disorders  mood disorders in which depression is unaccompanied by manic or hypomanic episodes.

developmental coordination disorder  problematic or delayed development of gross and fine motor coordination skills, not due to a neurological disorder or to general mental retardation, resulting in the appearance of clumsiness.

disruptive behavior disorders  a group of mental disorders of children and adolescents consisting of behavior that violates social norms and is disruptive.

dissociative disorders  mental disorders characterized by sudden, temporary alterations in identity, memory, or consciousness, segregating normally integrated parts of one's personality from one's dominant identity.

dissociative identity disorder  a dissociative disorder characterized by the existence in an individual of two or more distinct personalities, with at least two of the personalities controlling the patient's behavior in turns. The host personality usually is totally unaware of the alternate personalities; alternate personalities may or may not have awareness of the others.

dream anxiety disorder  nightmare d.

dysthymic disorder  a mood disorder characterized by depressed feeling, loss of interest or pleasure in one's usual activities, and other symptoms typical of depression but tending to be longer in duration and less severe than in major depressive disorder.

eating disorder  abnormal feeding habits associated with psychological factors, including anorexia nervosa, bulimia nervosa, pica, and rumination disorder.

expressive language disorder  a communication disorder occurring in children and characterized by problems with the expression of language, either oral or signed.

factitious disorder  a mental disorder characterized by repeated, intentional simulation of physical or psychological signs and symptoms of illness for no apparent purpose other than obtaining treatment.

factitious disorder by proxy  a form of factitious disorder in which one person (usually a mother) intentionally fabricates or induces physical (Munchausen syndrome by proxy) or psychological disorders in another person under their care (usually their child) and subjects that person to needless diagnostic procedures or treatment, without any external incentives for the behavior.

female orgasmic disorder  consistently delayed or absent orgasm in a female, even after a normal phase of sexual excitement and adequate stimulation.

female sexual arousal disorder  a sexual dysfunction involving failure by a female either to attain or maintain lubrication and swelling during sexual activity, after adequate stimulation.

functional disorder  a disorder of physiological function having no known organic basis.

gender identity disorder  a disturbance of gender identification in which the affected person has an overwhelming desire to change their anatomic sex or insists that they are of the opposite sex, with persistent discomfort about their assigned sex or about filling its usual gender role.

generalized anxiety disorder  (GAD) an anxiety disorder characterized by excessive, uncontrollable worry about two or more life circumstances for six months or more.

hypoactive sexual desire disorder  a sexual dysfunction consisting of persistently or recurrently low level or absence of sexual fantasies and desire for sexual activity.

impulse control disorders  a group of mental disorders characterized by repeated failure to resist an impulse to perform some act harmful to oneself or to others.

induced psychotic disorder  shared psychotic d.

intermittent explosive disorder  an impulse control disorder characterized by multiple discrete episodes of loss of control of aggressive impulses resulting in serious assault or destruction of property that are out of proportion to any precipitating stressors.

learning disorders  a group of disorders characterized by academic functioning that is substantially below the level expected on the basis of the patient's age, intelligence, and education.

lymphoproliferative disorders  a group of malignant neoplasms arising from cells related to the common multipotential lymphoreticular cell, including lymphocytic, histiocytic, and monocytic leukemias, multiple myeloma, plasmacytoma, and Hodgkin's disease.

lymphoreticular disorders  a group of disorders of the lymphoreticular system, characterized by the proliferation of lymphocytes or lymphoid tissues.

major depressive disorder  a mood disorder characterized by the occurrence of one or more major depressive episodes and the absence of any history of manic, mixed, or hypomanic episodes.

male erectile disorder  a sexual dysfunction involving failure by a male to attain or maintain an adequate erection until completion of sexual relations.

male orgasmic disorder  consistently delayed or absent orgasm in a male, even after a normal phase of sexual excitement and stimulation adequate for his age.

manic-depressive disorder  former name for a mood disorder now known as bipolar I d. or bipolar II d. and often called bipolar d. (q.v.).

mendelian disorder  a genetic disease showing a mendelian pattern of inheritance, caused by a single mutation in the structure of DNA, which causes a single basic defect with pathologic consequences.

mental disorder  any clinically significant behavioral or psychological syndrome characterized by the presence of distressing symptoms, impairment of functioning, or significantly increased risk of suffering death, pain, or other disability.

minor depressive disorder  a mood disorder closely resembling major depressive disorder and dysthymic disorder but intermediate in severity between the two.

mixed receptive-expressive language disorder  a communication disorder involving both the expression and the comprehension of language, either spoken or signed.

monogenic disorder  mendelian d.

mood disorders  mental disorders characterized by disturbances of mood manifested as one or more episodes of mania, hypomania, depression, or some combination, the two main subcategories being bipolar disorders and depressive disorders.

motor skills disorder  any disorder characterized by inadequate development of motor coordination severe enough to restrict locomotion or the ability to perform tasks, schoolwork, or other activities.

multifactorial disorder  one caused by the interaction of genetic and sometimes also nongenetic, environmental factors, e.g., diabetes mellitus.

multiple personality disorder  dissociative identity d.

myeloproliferative disorders  a group of usually neoplastic diseases possibly related histogenetically, including granulocytic leukemias, myelomonocytic leukemias, polycythemia vera, and myelofibroerythroleukemia.

neurotic disorder  neurosis.

nightmare disorder  repeated episodes of nightmares that awaken the sleeper, with full orientation and alertness and vivid recall of the dreams.

obsessive-compulsive disorder  (OCD) an anxiety disorder characterized by recurrent obsessions or compulsions, which are severe enough to interfere significantly with personal or social functioning. Cf. obsessive-compulsive personality disorder, under personality .

obsessive-compulsive personality disorder  see under personality.

oppositional defiant disorder  a type of disruptive behavior disorder characterized by a recurrent pattern of defiant, hostile, disobedient, and negativistic behavior directed toward those in authority.

organic mental disorder  a term formerly used to denote any mental disorder with a specifically known or presumed organic etiology. It was sometimes used synonymously with organic mental syndrome.

orgasmic disorders  sexual dysfunctions characterized by inhibited or premature orgasm; see female orgasmic d., male orgasmic d., and premature ejaculation.

pain disorder  a somatoform disorder characterized by a chief complaint of severe chronic pain which is neither feigned nor intentionally produced, but in which psychological factors appear to play a major role in onset, severity, exacerbation, or maintenance.

panic disorder  an anxiety disorder characterized by attacks of panic (anxiety), fear, or terror, by feelings of unreality, or by fears of dying, or losing control, together with somatic signs such as dyspnea, choking, palpitations, dizziness, vertigo, flushing or pallor, and sweating. It may occur with or, rarely, without agoraphobia.

paranoid disorder  older term for delusional d.

personality disorders  a category of mental disorders characterized by enduring, inflexible, and maladaptive personality traits that deviate markedly from cultural expectations and either generate subjective distress or significantly impair functioning. For specific disorders, see under personality.

pervasive developmental disorders  disorders in which there is impaired development in multiple areas, including reciprocal social interactions, verbal and nonverbal communications, and imaginative activity, as in autistic disorder.

phagocytic dysfunction disorders  a group of immunodeficiency conditions characterized by disordered phagocytic activity, occurring as both extrinsic and intrinsic types. Bacterial or fungal infections may range from mild skin infection to fatal systemic infection.

phobic disorders  see phobia.

phonological disorder  a communication disorder characterized by failure to use age- and dialect-appropriate sounds in speaking, with errors occurring in the selection, production, or articulation of sounds.

plasma cell disorders  see under dyscrasia.

postconcussional disorder  see under syndrome.

posttraumatic stress disorder  (PTSD) an anxiety disorder caused by an intensely traumatic event, characterized by mentally reexperiencing the trauma, avoidance of trauma-associated stimuli, numbing of emotional responsiveness, and hyperalertness and difficulty in sleeping, remembering, or concentrating.

premenstrual dysphoric disorder  premenstrual syndrome viewed as a psychiatric disorder.

psychoactive substance use disorders  substance use d's.

psychosomatic disorder  one in which the physical symptoms are caused or exacerbated by psychological factors, as in migraine headaches, lower back pain, or irritable bowel syndrome.

psychotic disorder  psychosis.

reactive attachment disorder  a mental disorder of infancy or early childhood characterized by notably unusual and developmentally inappropriate social relatedness, usually associated with grossly pathological care.

rumination disorder  excessive rumination of food by infants, after a period of normal eating habits, potentially leading to death by malnutrition.

schizoaffective disorder  a mental disorder in which symptoms of a mood disorder occur along with prominent psychotic symptoms characteristic of schizophrenia.

schizophreniform disorder  a mental disorder with the signs and symptoms of schizophrenia but of less than six months' duration.

seasonal affective disorder  (SAD) depression with fatigue, lethargy, oversleeping, overeating, and carbohydrate craving recurring cyclically during specific seasons, most commonly the winter months.

separation anxiety disorder  prolonged, developmentally inappropriate, excessive anxiety and distress in a child concerning removal from parents, home, or familiar surroundings.

sexual disorders 

1. any disorders involving sexual functioning, desire, or performance.

2. specifically, any such disorder that is caused at least in part by psychological factors; divided into sexual dysfunctions and paraphilias.

sexual arousal disorders  sexual dysfunctions characterized by alterations in sexual arousal; see female sexual arousal d. and male erectile d.

sexual aversion disorder  feelings of repugnance for and active avoidance of genital sexual contact with a partner, causing substantial distress or interpersonal difficulty.

sexual desire disorders  sexual dysfunctions characterized by alteration in sexual desire; see hypoactive sexual desire d. and sexual aversion d.

sexual pain disorders  sexual dysfunctions characterized by pain associated with intercourse; it includes dyspareunia and vaginismus not due to a general medical condition.

shared psychotic disorder  a delusional system that develops in one or more persons as a result of a close relationship with someone who already has a psychotic disorder with prominent delusions.

sleep disorders  chronic disorders involving sleep, either primary (dyssomnias, parasomnias) or secondary to factors including a general medical condition, mental disorder, or substance use.

sleep terror disorder  a sleep disorder of repeated episodes of pavor nocturnus.

sleepwalking disorder  a sleep disorder of the parasomnia group, consisting of repeated episodes of somnambulism.

social anxiety disorder  social phobia.

somatization disorder  a somatoform disorder characterized by multiple somatic complaints, including a combination of pain, gastrointestinal, sexual, and neurological symptoms, and not fully explainable by any known general medical condition or the direct effect of a substance, but not intentionally feigned or produced.

somatoform disorders  mental disorders characterized by symptoms suggesting physical disorders of psychogenic origin but not under voluntary control, e.g., body dysmorphic disorder, conversion disorder, hypochondriasis, pain disorder, somatization disorder, and undifferentiated somatoform disorder.

somatoform pain disorder  pain d.

speech disorder  defective ability to speak; it may be either psychogenic (see communication d. ) or neurogenic. See also aphasia, aphonia, dysphasia, and dysphonia.

stereotypic movement disorder  a mental disorder characterized by repetitive nonfunctional motor behavior that often appears to be driven and can result in serious self-inflicted injuries.

substance-induced disorders  a subgroup of the substance-related disorders comprising a variety of behavioral or psychological anomalies resulting from ingestion of or exposure to a drug of abuse, medication, or toxin. Cf. substance use d's.

substance-related disorders  any of the mental disorders associated with excessive use of or exposure to psychoactive substances, including drugs of abuse, medications, and toxins. The group is divided into substance use d's and substance-induced d's .

substance use disorders  a subgroup of the substance-related disorders, in which psychoactive substance use or abuse repeatedly results in significantly adverse consequences. The group comprises substance abuse and substance dependence.

undifferentiated somatoform disorder  one or more physical complaints, not intentionally produced or feigned and persisting for at least six months, that cannot be fully explained by a general medical condition or the direct effects of a substance.

unipolar disorders  depressive d's.