Since Acquired Immune Deficiency Syndrome (AIDS) manifests itself in a number of different diseases and conditions, it has been difficult to arrive at a formal definition. In an attempt to standardize the definition of AIDS, the Centers for Disease Control in 1992 included among its diagnostic criteria a count of 200 or fewer CD4T lymphocyte cells per cubic ml of blood (a sign of severe immune sys…
Adjustment disorders are maladpative, or unhealthy, responses to stressful or psychologically distressing life events, such as the end of a romantic relationship or being terminated from a job. The American Psychiatric Association has identified and categorized several varieties of adjustment disorders, depending on accompanying symptoms and their duration. These subtypes include adjustment disord…
Alzheimer's disease is the most common degenerative brain disorder, although onset of the disease is rare before the age of 60. After that age, the incidence of Alzheimer's disease increases steadily, and more than one-quarter of all individuals above the age of 85 have this disease. In addition, Alzheimer's disease is the cause of about three-quarters of all cases of dementia…
Symptoms of anorexia, or anorexia nervosa, include significant weight loss, continuation of weight loss despite thinness, persistent feeling of being fat even after weight loss, exaggerated fear of gaining weight, loss of menstrual periods, preoccupation with food, calories, nutrition and/or cooking, dieting in secret, compulsive exercising, sleep disorders, and a pattern of binging and purging. T…
Antisocial behavior can be broken down into two components: the presence of antisocial (i.e., angry, aggressive, or disobedient) behavior and the absence of prosocial (i.e., communicative, affirming, or cooperative) behavior. Most children exhibit some antisocial behavior during their development, and different children demonstrate varying levels of prosocial and antisocial behavior. Some children…
About 3% of males and 1% of females develop antisocial personality disorder, which is essentially the adult version of childhood conduct disorder. Antisocial personality disorder is only diagnosed in people over age 18, the symptoms are similar to those of conduct disorder, and the criteria for diagnosis include the onset of conduct disorder before the age of 15. According to the Diagnostic and St…
Stimulated by real or imagined dangers, anxiety afflicts people of all ages and social backgrounds. When the anxiety results from irrational fears, it can disrupt or disable normal life. Some researchers believe anxiety is synonymous with fear, occurring in varying degrees and in situations where people feel threatened by some danger. Others describe anxiety as an unpleasant emotion caused by unid…
In contrast to neurological problems that affect the physical ability to speak or perform other linguistic functions, aphasia involves the mental ability to manipulate speech sounds, vocabulary, grammar, and meaning. There are several different types of aphasia. Each has different symptoms and is caused by damage to a different part of the brain. The great majority of aphasias are caused by damage…
Attention deficit/hyperactivity disorder (ADHD) refers to a combination of excessive motor restlessness, difficulty in controlling or maintaining attention to relevant events, and impulsive responding that is not adaptive. Children and adults experience the symptoms of ADHD in most areas of their life. It affects their performance in school or at work, depending on their age, and it affects them s…
First described by Dr. Leo Kanner in 1943, autism is a severe psychological disorder that affects an estimated four children in 10,000. Autism manifests itself in early childhood. The autistic child is impaired socially, in language development, and exhibits other behavioral problems. This disorder is also known as infantile or childhood autism and Kanner's autism. The occurrence of autism …
Bipolar disorder is classified among affective disorders in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders . The National Institute of Mental Health (NIMH) estimates that about one in one hundred people will develop the disorder, which affects some two million Americans. While this condition occurs equally in both males and females and in every …
It has recently been reported that neurology, the study of the brain, is the fastest growing specialty in the life sciences. With this growth has come a wealth of new information about the origins of and treatments for some of the more prevalent brain disorders. There are many varieties of brain disorders that affect humans, including Alzheimer's disease, Parkinson's disease, epileps…
Episodes that are classified as brief reactive psychoses may last more than two hours but less than one month. Typical triggering events can be the death of a spouse or other loved one, combat trauma, financial disaster, or any other major event involving psychosocial stress. Brief reactive psychosis has a sudden onset, typically in late adolescence and early adulthood, and is characterized by del…
The symptoms of bulimia, or bulimia nervosa, include eating uncontrollably (binging) and then purging by dieting, fasting, exercising, vomiting, or abusing laxatives or diuretics. A binge involves a large amount of food, for example, several boxes of cookies, a loaf of bread, a half gallon of ice cream, and a bucket of fried chicken, eaten in a short and well-defined time period. Specific behavior…
Language employs symbols—words, gestures, or spoken sounds—to represent objects and ideas. Communication of language begins with spoken sounds combined with gestures, relying on two different types of skills. Children first acquire the skills to receive communications, that is, listening to and understanding what they hear (supported by accompanying gestures). Next, they will begin e…
This condition was first described by Sigmund Freud as conversion hysteria because it involved the conversion of a repressed emotional problem to a physiological form. Today, conversion reaction is classified as a somatoform disorder in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV ). Conversion reaction is a very rare condition, accoun…
Delirious behavior ranges from mildly inappropriate to maniacal, and is a symptom of a number of disorders. Delirium has been classified into several varieties, based primarily on causal factors. As an example, alcohol-withdrawal delirium, which is also called delirium tremens or D.T.s (because of the characteristic tremor), is an acute delirium related to physical deterioration and the abrupt low…
Delusions are generally experienced by people suffering from a severe psychotic disorder, usually schizophrenia, although delusional thinking can occur in other types of patients (as the result of drug or alcohol abuse, for instance). Typical delusional ideas are categorized into delusions of grandeur, in which a person imagines for him or herself some God-given purpose or, in some cases, believe …
Persons affected by dependent personality disorder have a disproportionately low level of confidence in their own intelligence and abilities and have difficulty making decisions and undertaking projects on their own. Their pervasive reliance on others, even for minor tasks or decisions, makes them exaggeratedly cooperative out of fear of alienating those whose help they need. They are reluctant to…
Also referred to as reading disability, reading difficulty, and dyslexia, developmental reading disorder is the most commonly diagnosed learning disability in the United States. Estimates of its prevalence vary widely, ranging from 4% of children—the figure given by the American Psychiatric Association's Diagnostic and Statistical Manual—to 20%, the figure given by a 1995 stud…
Dissociation, or the feeling of being detached from the reality of one's body, can be categorized into two types: depersonalization and derealization. Depersonalization is highlighted by a sense of not knowing who you are, or of questioning long-held beliefs about who you are. In derealization, persons perceive reality in a grossly distorted way. Psychologists have identified several types …
Down syndrome was named after John Langdon Haydon Down, a British physician and advocate of education for the mentally retarded, who first described it in 1866. In 1959, the French pediatrician Jerome Lejeune discovered that the disorder is caused by a chromosomal abnormality. Ninety-five percent of individuals with Down syndrome have Trisomy 21, an extra chromosome in the 21st pair (altogether, t…
Eating disorders are rooted in complex emotional issues that center on self-esteem and pervasive societal messages that equate thinness with happiness. Eating disorders usually surface in adolescence, and more than 90% of sufferers are female, although the incidence among males appears to be growing. Because eating disorders are neither purely physical nor purely psychological, effective treatment…
Disorders traditionally classified as neuroses (including a variety of anxiety and mood disorders as well as psychosomatic illnesses) are generally regarded as functional disorders. While conditions classified as psychotic are usually believed to have biological origins, neurotic conditions are generally believed to be caused by developmental, psychosocial, or personality factors. Psychotic disord…
Researchers have suggested that both early socialization and prenatal hormones may play an important role in the development of transsexuality. It is estimated that about 1 in 20,000 males and 1 in 50,000 females are transsexuals. Gender identity disorder generally begin to manifest between the ages of two and four, in which a child displays a preference for the clothing and typical activities of …
Individuals with histrionic personality disorder tend to seek attention by exaggerating events, even if insignificant, and are immature, self-centered and often vain. They react emotionally to the slightest provocation. Histrionic personality disorder is classified by psychologists with the group of personality disorders characterized by overly dramatic, emotional, impulsive or erratic reactions. …
Impulse control disorders are thought to have both neurological and environmental causes and are known to be exacerbated by stress. Some mental health professionals regard several of these disorders, such as compulsive gambling or shopping, as addictions. In impulse control disorder, the impulse action is typically preceded by feelings of tension and excitement and followed by a sense of relief an…
Persons with this disorder, popularly referred to as kleptomaniacs, experience a recurring urge to steal that they are unable to resist. They do not steal for the value of the item, for its use, or because they cannot afford the purchase. The individual knows that it is wrong to steal. Stolen items are often thrown or given away, secretly returned to the store from which they were taken, or hidden…
In adults, much of what is known about the organization of language functions in the brain has come from the study of patients with focal brain lesions. It has been known for hundreds of years that a left-hemisphere injury to the brain is more likely to cause language disturbance—aphasia—than a right hemisphere injury, especially but not exclusively in right-handed persons. For about…
Most episodes of mania—elation without reasonable cause or justification—are followed in short order by depression; together they represent the opposites described as bipolar disorder. Manic episodes are characterized by intense feelings of energy and enthusiasm, uncharacteristic self-confidence, continuous talking, and little need for sleep. People experiencing a manic period tend t…
The term "melancholia" is derived from the Greek words melas, meaning black, and chole, meaning bile, and is a vestige of the ancient belief that a person's health and temperament are determined by the relative proportions of the four cardinal humors, or body fluids, which are blood, phlegm, choler (yellow bile), and melancholy (black bile). The central feature of melancholic …
After decades of concentrating on mental illness and emotional disorders, many psychologists during the 1950s turned their focus toward the promotion of mental health. Attempts to prevent mental illness joined the emphasis on treatment methods, and promotion of "self-help" in many cases replaced the dependence on professionals and drug therapies. American psychologist Gordon Allport …
Beginning in the Middle Ages, mental hospitals were basically prisons. By the end of the eighteenth century, the term asylum was used, and some reforms were being implemented when the notion was introduced that psychological disturbances, like physical ailments, could be viewed as diseases requiring treatment rather than crimes calling for imprisonment. By the late 1800s, reactions against conditi…
Many mental hospitals are modernizing their treatment methods, including this one with patients participating in dance therapy. (Photo Researchers, Inc. Reproduced with permission.) Mental illness is a serious public health problem. According to the World Health Organization and the Harvard School of Public Health, mental illness accounts for nearly 11 percent of total worldwide disease bur…
The term mental retardation is commonly used to refer to people with an intelligence quotient (IQ) below70. An IQ of 80-130 is considered the normal range, and 100 is considered average. According to the definition in the American Psychiatric Association's Diagnostic and Statistical Manual (DSM-IV), a mentally retarded person is significantly limited in at least two of the following areas: …
Minimal brain dysfunction was formally defined in 1966 by Samuel Clements as a combination of average or above average intelligence with certain mild to severe learning or behavioral disabilities characterizing deviant functioning of the central nervous system. It can involve impairments in visual or auditory perception, conceptualization, language, and memory, and difficulty controlling attention…
Narcolepsy, which usually begins in adolescence or early adulthood, affects about one in every 1,000 persons and is equally common in males and females. The sleep attacks, which can occur anywhere from six to 20 times a day, usually last about 10 to 20 minutes but can persist for as long as two to three hours. Narcolepsy is diagnosed if sleep attacks occur every day for at least three months (alth…
Depending on the population, 2-6% of children have oppositional-defiant disorder. Oppositional-defiant disorder is similar to conduct disorder, without the more severe behavior components of aggression, property destruction, deceit, and theft. Oppositional-defiant children often go on to develop conduct disorder. Many children, especially during transitional periods such as preschool and adolescen…
Feelings of fear and panic are common to all species, and humans are certainly no exception. Psychologically speaking, however, panic can be an obtrusive, life-altering phenomena for many people who suffer panic attacks. Such attacks occur commonly in people suffering from various phobias. People suffering from agoraphobia, for instance, can expect to suffer panic attacks when out in public. While…
Paranoia is an ever-present feeling of suspicion that others cannot be trusted. Such feelings are not based on fact or reality; insecurity and low self-esteem often exaggerate these emotions. Typically, paranoia is not seen in children, but in most cases it begins to develop in late adolescence and early adulthood. Most people experience feelings of paranoia, usually in response to a threatening s…
Parkinson's disease is a degenerative disorder of the central nervous system named for James Parkinson (1755-1824), the physician who first described it in 1817. This disorder is also called paralysis agitans, shaking palsy, or parkinsonism. Typically, the symptoms of Parkinson's disease begin to appear in late middle life, and the course of the disease is slowly progressive over 20 …
Formerly listed among the personality disorders in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, the passive-aggressive personality type has been described by a number of psychologists and psychiatrists, including Karen Horney, Karl Menninger, and Wilhelm Reich (1897-1957). Its main distinguishing feature is indirect resistance to the demands …
Personality disorders constitute a separate diagnostic category (Axis II) in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Unlike the major mental disorders (Axis I), which are characterized by periods of illness and remission, personality disorders are generally ongoing. Often, they first appear in childhood or adolescence and persis…
The incidence of pervasive development disorders (PDDs) in the general population is estimated at 1%. These disorders are thought to be genetically based, and there is no evidence linking them to environmental factors. Many children who are diagnosed with PDDs today would have been labeled psychotic or schizophrenic in the past. The most serious form of pervasive developmental disorder is autism, …
Although the term post-traumatic stress disorder is relatively new, the symptoms of PTSD can be recognized in many guises throughout history, from the reactions to the great fire of London that Samuel Pepys (1633-1703) described in the 1600s to the "shell shock" of soldiers in World War I. Some psychologists suspect that the "hysterical" women treated by Josef Breuer (1…
While psychological disorders are generally signaled by some form of abnormal behavior or thought process, abnormality can be difficult to define, especially since it varies from culture to culture. Psychologists have several standard approaches to defining abnormality for diagnostic purposes. One is the statistical approach, which evaluates behavior by determining how closely it conforms to or de…
Psychosis may appear as a symptom of a number of mental disorders, including mood and personality disorders, schizophrenia, delusional disorder, and substance abuse. It is also the defining feature of the psychotic disorders (i.e., brief psychotic disorder, shared psychotic disorder, psychotic disorder due to a general medical condition, and substance-induced psychotic disorder). Patients sufferin…
The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSMIV) classifies psychosomatic illnesses under "Psychological Factors Affecting Physical Conditions." Physicians have been aware that people's mental and emotional states influence their physical well-being since the time of Hippocrates. In the twentieth century, the discoveri…
Formerly, all psychological disorders were considered either psychotic or neurotic. Psychotic disorders were those that rendered patients unable to function normally in their daily lives and left them "out of touch with reality." They were associated with impaired memory, language, and speech and an inability to think rationally. Neurotic disorders, by comparison, were characterized …
Little is known about pyromania. The term comes from the Greek words pyr (fire) and mania (madness). It is a rare condition, listed under the heading of impulse control disorders. Pyromania is not the same as arson (deliberate fire-setting), and not all arsonists (fire-setters) are pyromaniacs. Fires are often started by individuals with this disorder deliberately and with careful planning, rather…
Persons who display savant syndrome have traditionally been called idiot savants, a term that many currently avoid because of its negative connotations. Alternate terms include retarded savant and autistic savant, the latter referring to the fact that savant syndrome is often associated with autism. It is difficult to arrive at an exact figure for the incidence of savant syndrome. A 1977 study fou…
Some experts view schizophrenia as a group of related illnesses with similar characteristics. The condition affects between one-half and one percent of the world's population, occurring with equal frequency in males and females (although the onset of symptoms is usually earlier in males). Between 1 and 2% of Americans are thought to be afflicted with schizophrenia—at least 2.5 millio…
Sexual dysfunction involves both somatic and psychic phenomena which contribute to an overall inability or lack of interest in performing sexually. In males, the condition is most associated with erectile dysfunction (ED), formerly referred to as male "impotence." Studies estimate that 10-20 million American males have some degree of ED, which clinically presents as a persistent inab…
An estimated 15 percent of Americans have chronic sleep problems, while about 10 percent have occasional trouble sleeping. Sleep disorders are listed among the clinical syndromes in Axis I of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. They may be either primary (unrelated to any other disorder, medical or psychological) or secondary (the re…
Physical symptoms of test anxiety include a rapid heartbeat, dry mouth, sweating, stomach ache, dizziness, and desire to urinate. The anxiety interferes with concentration and memory, making it difficult or impossible to recall previously memorized material and resulting in test performance that does not accurately reflect a person's intelligence or the amount of effort spent preparing for …
Tourette syndrome (TS) affects roughly one in every 2,500 persons. The incidence of the condition is at least three times higher in males than in females. Historically, Tourette syndrome has been a largely misunderstood condition; it has been identified as demonic possession, epilepsy, schizophrenia, and other mental disorders, and was formerly thought to be the result of emotional problems due to…