VII.

Kinds of Mental Illnesses

A number of mental illnesses—such as depression, anxiety disorders, schizophrenia, and bipolar disorder—occur worldwide. Others seem to occur only in particular cultures. For example, eating disorders, such as anorexia nervosa (compulsive dieting associated with unrealistic fears of fatness), occur mostly among girls and women in Europe, North America, and Westernized areas of Asia, whose cultures view thinness as an essential component of female beauty. In Latin America, people who experience overwhelming fright after a dangerous or traumatic event are said to have susto (fright), an illness in which their soul has been frightened away. In some societies of West Africa and elsewhere, brain fag describes individuals (usually students) who experience difficulties in concentrating and thinking, as well as physical symptoms of pain and fatigue.

Most mental health professionals in the United States use the Diagnostic and Statistical Manual of Mental Disorders(DSM), a reference book published by the American Psychiatric Association, as a guide to the different kinds of mental illnesses. The fourth edition, known as DSM-IV, describes more than 300 mental disorders, behavioral disorders, addictive disorders, and other psychological problems and groups them into broad categories. This article describes some of the major categories, including anxiety disorders, mood disorders, schizophrenia and other psychotic disorders, personality disorders, cognitive disorders, dissociative disorders, somatoform disorders, factitious disorders, substance-related disorders, eating disorders, and impulse-control disorders. Mental health professionals in many other parts of the world use a different classification system, the International Classification of Diseases (ICD), published by the World Health Organization.

The DSM and ICD are both categorical systems of classification, in which each mental illness is defined by its own unique set of symptoms and characteristics. In theory, each disorder should possess diagnostic criteria that are independent of one another, just as tuberculosis and lung cancer are discrete diseases. Yet symptoms of many mental disorders overlap, and many people—such as those who experience both depression and severe anxiety—show symptoms of more than one disorder at the same time. For these reasons, some mental health professionals advocate a dimensional system of classification. In contrast to the categorical approach, which sees mental disorders as qualitatively distinct from normal behavior, a dimensional system views behavior as falling along a continuum of normality, with some behaviors considered more abnormal than others. In a dimensional system, diagnoses do not describe discrete diseases but rather portray the relative importance of an array of symptoms.

Definitions and classifications of mental illnesses change as research improves understanding of them. For example, DSM-IV allows a diagnosis of schizophrenia only when characteristic symptoms have lasted at least one month, whereas the previous edition of DSM required a duration of only one week.

A.

Anxiety Disorders

Anxiety disorders involve excessive apprehension, worry, and fear. People with generalized anxiety disorder experience constant anxiety about routine events in their lives. Phobias are fears of specific objects, situations, or activities. Panic disorder is an anxiety disorder in which people experience sudden, intense terror and such physical symptoms as rapid heartbeat and shortness of breath. People with obsessive-compulsive disorder experience intrusive thoughts or images (obsessions) or feel compelled to perform certain behaviors (compulsions). People with post-traumatic stress disorder relive traumatic events from their past and feel extreme anxiety and distress about the event.

B.

Mood Disorders

Mood disorders, also called affective disorders, create disturbances in a person’s emotional life. Depression, mania, and bipolar disorder are examples of mood disorders. Symptoms of depression may include feelings of sadness, hopelessness, and worthlessness, as well as complaints of physical pain and changes in appetite, sleep patterns, and energy level. In mania, on the other hand, an individual experiences an abnormally elevated mood, often marked by exaggerated self-importance, irritability, agitation, and a decreased need for sleep. In bipolar disorder, also called manic-depressive illness, a person’s mood alternates between extremes of mania and depression.

C.

Schizophrenia and Other Psychotic Disorders

People with schizophrenia and other psychotic disorders lose contact with reality. Symptoms may include delusions and hallucinations, disorganized thinking and speech, bizarre behavior, a diminished range of emotional responsiveness, and social withdrawal. In addition, people who suffer from these illnesses experience an inability to function in one or more important areas of life, such as social relations, work, or school. See Psychosis.

D.

Personality Disorders

Personality disorders are mental illnesses in which one’s personality results in personal distress or a significant impairment in social or work functioning. In general, people with personality disorders have poor perceptions of themselves or others. They may have low self-esteem or overwhelming narcissism, poor impulse control, troubled social relationships, and inappropriate emotional responses. Considerable controversy exists over where to draw the distinction between a normal personality and a personality disorder.

E.

Cognitive Disorders

Cognitive disorders, such as delirium and dementia, involve a significant loss of mental functioning. Dementia, for example, is characterized by impaired memory and difficulties in such functions as speaking, abstract thinking, and the ability to identify familiar objects. The conditions in this category usually result from a medical condition, substance abuse, or adverse reactions to medication or poisonous substances. See Senile Dementia.

F.

Dissociative Disorders

Dissociative disorders involve disturbances in a person’s consciousness, memories, identity, and perception of the environment. Dissociative disorders include amnesia that has no physical cause; dissociative identity disorder, in which a person has two or more distinct personalities that alternate in their control of the person’s behavior; depersonalization disorder, characterized by a chronic feeling of being detached from one’s body or mental processes; and dissociative fugue, an episode of sudden departure from home or work with an accompanying loss of memory. In some parts of the world people experience dissociative states as “possession” by a god or ghost instead of separate personalities. In many societies, trance and possession states are normal parts of cultural and religious practices and are not considered dissociative disorders.

G.

Somatoform Disorders

Somatoform disorders are characterized by the presence of physical symptoms that cannot be explained by a medical condition or another mental illness. Thus, physicians often judge that such symptoms result from psychological conflicts or distress. For example, in conversion disorder, also called hysteria, a person may experience blindness, deafness, or seizures, but a physician cannot find anything wrong with the person. People with another somatoform disorder, hypochondriasis (see Hypochondria), constantly fear that they will develop a serious disease and misinterpret minor physical symptoms as evidence of illness. The term somatoform comes from the Greek word soma, meaning “body.”

H.

Factitious Disorders

In contrast to people with somatoform disorders, people with factitious disorders intentionally produce or fake physical or psychological symptoms in order to receive medical attention and care. For example, an individual might falsely report shortness of breath to gain admittance to a hospital, report thoughts of suicide to solicit attention, or fabricate blood in the urine or the symptoms of rash so as to appear ill. Munchausen syndrome represents the most extreme and chronic variant of the factitious disorders.

I.

Substance-Related Disorders

Substance-related disorders result from the abuse of drugs, side effects of medications, or exposure to toxic substances. Many mental health professionals regard these disorders as behavioral or addictive disorders rather than as mental illnesses, although substance-related disorders commonly occur in people with mental illnesses. Common substance-related disorders include alcoholism and other forms of drug dependence. In addition, drug use can contribute to symptoms of other mental disorders, such as depression, anxiety, and psychosis. Drugs associated with substance-related disorders include alcohol, caffeine, nicotine, cocaine, heroin (see Opium), amphetamines, hallucinogens, and sedatives.

J.

Eating Disorders

Eating disorders are conditions in which an individual experiences severe disturbances in eating behaviors. People with anorexia nervosa have an intense fear about gaining weight and refuse to eat adequately or maintain a normal body weight. People with bulimia nervosa (see Bulimia) repeatedly engage in episodes of binge eating, usually followed by self-induced vomiting or the use of laxatives, diuretics, or other medications to prevent weight gain. Eating disorders occur mostly among young women in Western societies and certain parts of Asia.

K.

Impulse-Control Disorders

People with impulse-control disorders cannot control an impulse to engage in harmful behaviors, such as explosive anger, stealing (kleptomania), setting fires (pyromania), gambling (see Pathological Gambling), or pulling out their own hair (trichotillomania). Some mental illnesses—such as mania, schizophrenia, and antisocial personality disorder—may include symptoms of impulsive behavior.