Dementia is not a specific disorder or disease. It is a syndrome (group of symptoms) associated with a progressive loss of memory and other intellectual functions that is serious enough to interfere with performing the tasks of daily life.


Denial is the refusal to acknowledge the existence or severity of unpleasant external realities or internal thoughts and feelings.

Dependent personality disorder

Dependent personality disorder is characterized by an excessive need to be taken care of or depend upon others. Persons with this disorder are typically submissive and display clinging behavior toward those from whom they fear being separated.


Depersonalization is a mental state in which a person feels detached or disconnected from his or her personal identity or self. This may include the sense that one is "outside" oneself, or is observing one's own actions, thoughts or body.

Depersonalization disorder

Depersonalization is a state in which the individual ceases to perceive the reality of the self or the environment. The patient feels that his or her body is unreal, is changing, or is dissolving; or that he or she is outside of the body.

Depression and depressive disorders

Depression or depressive disorders (unipolar depression) are mental illnesses characterized by a profound and persistent feeling of sadness or despair and/or a loss of interest in things that were once pleasurable. Disturbance in sleep, appetite, and mental processes are a common accompaniment.


Desipramine is an antidepressant drug used to elevate mood and promote recovery of a normal range of emotions in patients with depressive disorders. In addition, desipramine has uses in a number of other psychiatric and medical conditions.


Detoxification is a process in which the body is allowed to free itself of a drug. During this period, the symptoms of withdrawal are also treated.

Developmental coordination disorder

Developmental coordination disorder is diagnosed when children do not develop normal motor coordination (coordination of movements involving the voluntary muscles).


Diagnosis can be defined as the identification and labeling of a disease based on its signs and symptoms. Mental health clinicians (psychiatrists, psychologists, and psychiatric nurse practitioners) diagnose mental disorders using the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM, published by the American Psychiatric Association.

Diagnostic and Statistical Manual of Mental Disorders

The Diagnostic and Statistical Manual of Mental Disordersis a reference work consulted by psychiatrists, psychologists, physicians in clinical practice, social workers, medical and nursing students, pastoral counselors, and other professionals in health care and social service fields. The book's title is often shortened to DSM, or an abbreviation that also indicates edition, such as DSM-IV-TR,which indicates fourth edition, text revision of the manual, published in 2000.


Diazepam is a mild tranquilizer in the class of drugs known as benzodiazepines. It is most commonly sold in the United States under the brand name Valium.


Special diets are designed to help individuals make changes in their usual eating habits or food selection. Some special diets involve changes in the overall diet, such as diets for people needing to gain or lose weight or eat more healthfully.


Diphenhydramine is an antihistamine used in psychiatric medicine to treat phenothiazine drug-induced abnormal muscle movement. It is also used in general medicine to treat allergies, allergic reactions, motion sickness, insomnia, cough, and nausea.

Disease concept of chemical dependency

Disease concept of chemical dependency is the concept that a disorder (such as chemical dependency) is like a disease and has a characteristic set of signs, symptoms, and natural history (clinical course, or outcome).

Disorder of written expression

Disorder of written expression, formerly called developmental expressive writing disorder, is a learning disability in which a person's ability to communicate in writing is substantially below the level normally expected based on the individual's age, intelligence, life experiences, educational background, or physical impairments. This disability affects both the physical reproduction of letters and words and the organization of thoughts and ideas in written compositions.

Dissociation and dissociative disorders

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

Dissociative amnesia

Dissociative amnesiais classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, also known as the DSM-IV-TR as one of the dissociative disorders, which are mental disorders in which the normally well-integrated functions of memory, identity, perception, or consciousness are separated (dissociated). The dissociative disorders are usually associated with trauma in the recent or distant past, or with an intense internal conflict that forces the mind to separate incompatible or unacceptable knowledge, information, or feelings.

Dissociative fugue

Dissociative fugue is a rare condition in which a person suddenly, without planning or warning, travels far from home or work and leaves behind a past life. Patients show signs of amnesiaand have no conscious understanding or knowledge of the reason for the flight.

Dissociative identity disorder

Previously known as multiple personality disorder, dissociative identity disorder (DID) is a condition in which a person has more than one distinct identity or personality state. At least two of these personalities repeatedly assert themselves to control the affected person's behavior.


Disulfiram is an aldehyde dehydrogenase inhibitor. It prohibits the activity of aldehyde dehydrogenase, an enzyme found in the liver.

Divalproex sodium

Divalproex sodium is an anticonvulsant (antiseizure) drug. It is also used to treat mania and to help prevent migraine headaches.


Donepezil is a drug used to treat dementia associated with Alzheimer's disease. In the United States, donepezil is sold under the brand name Aricept.


Doxepin is an oral antidepressant. It is sold in the United States under the brand name Sinequan and is also available under its generic name.

Dual diagnosis

Dual diagnosis is a term that refers to patients who have both a mental health disorder and substance use disorder. It may be used interchangeably with "co-occurring disorders" or "comorbidity." According to the U.S.


Dyspareunia is painful sexual intercourse. The same term is used whether the pain results from a medical or a psychosocial problem.

Dysthymic disorder

Dysthymic disorder is defined as a mood disorder with chronic (long-term) depressive symptoms that are present most of the day, more days than not, for a period of at least two years.

Electroconvulsive therapy

Electroconvulsive therapy (ECT) is a medical procedure in which a small, carefully controlled amount of electric current is passed through the brainto treat symptoms associated with certain mental disorders. The electric current produces a convulsion for the relief of symptoms associated with such mental illnesses as major depressive disorder, bipolar disorder, acute psychosis, and catatonia.


Electroencephalography (EEG) is a neurological diagnostic procedure that records the changes in electrical potentials (brainwaves) in various parts of the brain.

Elimination disorders

Elimination disorders are disorders that concern the elimination of feces or urine from the body. The causes of these disorders may be medical or psychiatric.


Encopresis is an elimination disorder that involves repeatedly having bowel movements in inappropriate places after the age when bowel control is normally expected.

Energy therapies

Energy therapies is a collective term used to refer to a variety of alternative and complementary treatments based on the use, modification, or manipulation of energy fields. Most energy therapies presuppose or accept the theory that matter and energy are not exclusive opposites, but that matter is simply a denser form of energy that is more easily perceived by the senses.


Enuresis, more commonly called bed-wetting, is a disorder of elimination that involves the voluntary or involuntary release of urine into bedding, clothing, or other inappropriate places. In adults, loss of bladder control is often referred to as urinary incontinence rather than enuresis; it is frequently found in patients with late-stage Alzheimer's disease or other forms of dementia.

Erectile dysfunction

Erectile dysfunction (ED) may be defined as the consistent inability to achieve or maintain an erection sufficient to permit satisfactory sexual intercourse. The word "consistent" is included in the definition because most men experience transient episodes of ED that are temporary and usually associated with fatigue, anger, depression or other stressful emotions.


Estazolam is a sedative-hypnotic drug belonging to the class of drugs known as benzodiazepines. It is sold in the United States under the names ProSom and Sedarest.

Evening primrose oil

Evening primrose oil is a dietary supplement derived from the seeds of the evening primrose plant, Oenothera biennis. Its Latin name is derived from the Greek word for wine, reflecting the folk belief that the plant could relieve the symptoms of a hangover.

Executive function

The term executive function describes a set of cognitive abilities that control and regulate other abilities and behaviors. Executive functions are necessary for goal-directed behavior.


Exhibitionism is a mental disorder characterized by a compulsion to display one's genitals to an unsuspecting stranger. The Diagnostic and Statistical Manual of Mental Disorders,also known as the DSM-IV-TR,classifies exhibitionism under the heading of the "paraphilias," a subcategory of sexual and gender identity disorders.

Exposure treatment

Exposure treatment is a technique that is widely used in cognitive-behavioral therapy (CBT). Exposure treatment is used for a variety of anxiety disorders, and it has also recently been extended to the treatment of substance-related disorders.

Expressive language disorder

Expressive language disorder occurs when an individual has problems expressing him or herself using spoken language.

Factitious disorder

Factitious disorder (FD) is an umbrella category that covers a group of mental disturbances in which patients intentionally act physically or mentally ill without obvious benefits. According to one estimate, the unnecessary tests and waste of other medical resources caused by FD cost the United States $40 million per year.

Family education

Family education is the ongoing process of educating family members about a serious mental illness in order to improve their coping skills and their ability to help a relative affected by the illness.

Family psychoeducation

Family psychoeducation is a method based on clinical findings for training families to work together with mental health professionals as part of an overall clinical treatment plan for their family members. Family psychoeducation has been shown to improve patient outcomes for persons with schizophreniaand other major mental illnesses.

Family therapy

Family therapy is a form of psychotherapythat involves all the members of a nuclear or extended family. It may be conducted by a pair of therapists—often a man and a woman—to treat gender-related issues or serve as role models for family members.


Fatigue may be defined as a subjective state in which one feels tired or exhausted, and in which the capacity for normal work or activity is reduced. There is, however, no commonly accepted definition of fatigue when it is considered in the context of health and illness.

Feeding disorder of infancy or early childhood

Feeding disorder of infancy or early childhood is characterized by the failure of an infant or child under six years of age to eat enough food to gain weight and grow normally over a period of one month or more. The disorder can also be characterized by the loss of a significant amount of weight over one month.

Female orgasmic disorder

Female orgasmic disorder (FOD) is the persistent or recurrent inability of a woman to have an orgasm (climax or sexual release) after adequate sexual arousal and sexual stimulation. According to the handbook used by mental health professionals to diagnose mental disorders, the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (also known as the DSM-IV-TR), this lack of response can be primary (a woman has never had an orgasm) or secondary (acquired after trauma), and can be either general or situation-specific.

Female sexual arousal disorder

Female sexual arousal disorder (FSAD) refers to the persistent or recurrent inability of a woman to achieve or maintain an adequate lubrication-swelling response during sexual activity. This lack of physical response may be either lifelong or acquired, and either generalized or situation-specific.


Fetishism is a form of paraphilia, a disorder that is characterized by recurrent intense sexual urges and sexually arousing fantasies generally involving non-human objects, the suffering or humiliation of oneself or one's partner (not merely simulated), or children or other non-consenting persons. The essential feature of fetishism is recurrent intense sexual urges and sexually arousing fantasies involving specific objects.

Figure drawings

Figure drawings are projective diagnostic techniques in which an individual is instructed to draw a person, an object, or a situation so that cognitive, interpersonal, or psychological functioning can be assessed.