Theories of personality development
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Freudian and other psychodynamic theories view neurotic symptoms as arising from intrapsychic conflict—i.e., the existence of conflicting motives, drives, impulses, and feelings held within various components of the mind. Central to psychoanalytic theory is the postulated existence of the unconscious, which is that part of the mind whose processes and functions are inaccessible to the individual’s conscious awareness or scrutiny. One of the functions of the unconscious is thought to be that of a repository for traumatic memories, feelings, ideas, wishes, and drives that are threatening, abhorrent, anxiety-provoking, or socially or ethically unacceptable to the individual. These mental contents may at some time be pushed out of conscious awareness but remain actively held in the unconscious. This process is a defense mechanism for protecting the individual from the anxiety or other psychic pain associated with those contents and is known as repression. The repressed mental contents held in the unconscious retain much of the psychic energy or power that was originally attached to them, however, and they can continue to influence significantly the mental life of the individual even though (or because) a person is no longer aware of them.
The natural tendency for repressed drives or feelings, according to this theory, is to reach conscious awareness so that the individual can seek the gratification, fulfillment, or resolution of them. But this threatened release of forbidden impulses or memories provokes anxiety and is seen as threatening, and a variety of defense mechanisms may then come into play to provide relief from the state of psychic conflict. Through reaction formation, projection, regression, sublimation, rationalization, and other defense mechanisms, some component of the unwelcome mental contents can emerge into consciousness in a disguised or attenuated form, thus providing partial relief to the individual. Later, perhaps in adult life, some event or situation in the person’s life triggers the abnormal discharge of the pent-up emotional energy in the form of neurotic symptoms in a manner mediated by defense mechanisms. Such symptoms can form the basis of neurotic disorders such as conversion and somatoform disorders (see below somatoform disorders), anxiety disorders, obsessional disorders, and depressive disorders. Since the symptoms represent a compromise within the mind between letting the repressed mental contents out and continuing to deny all conscious knowledge of them, the particular character and aspects of an individual’s symptoms and neurotic concerns bear an inner meaning that symbolically represents the underlying intrapsychic conflict. Psychoanalysis and other dynamic therapies help a person achieve a controlled and therapeutic recovery that is based on a conscious awareness of repressed mental conflicts along with an understanding of their influence on past history and present difficulties. These steps are associated with the relief of symptoms and improved mental functioning.
Freudian theory views childhood as the primary breeding ground of neurotic conflicts. This is because children are relatively helpless and are dependent on their parents for love, care, security, and support and because their psychosexual, aggressive, and other impulses are not yet integrated into a stable personality framework. The theory posits that children lack the resources to cope with emotional traumas, deprivations, and frustrations; if these develop into unresolved intrapsychic conflicts that the young person holds in abeyance through repression, there is an increased likelihood that insecurity, unease, or guilt will subtly influence the developing personality, thereby affecting the person’s interests, attitudes, and ability to cope with later stresses.
Non-Freudian psychodynamics
Psychoanalytic theory’s emphasis on the unconscious mind and its influence on human behavior resulted in a proliferation of other, related theories of causation incorporating—but not limited to—basic psychoanalytic precepts. Most subsequent psychotherapies have stressed in their theories of causation aspects of earlier, maladaptive psychological development that had been missed or underemphasized by orthodox psychoanalysis, or they have incorporated insights taken from learning theory. Swiss psychiatrist Carl Jung, for instance, concentrated on the individual’s need for spiritual development and concluded that neurotic symptoms could arise from a lack of self-fulfillment in this regard. Austrian psychiatrist Alfred Adler emphasized the importance of feelings of inferiority and the unsatisfactory attempts to compensate for it as important causes of neurosis. Neo-Freudian authorities such as Harry Stack Sullivan, Karen Horney, and Erich Fromm modified Freudian theory by emphasizing social relationships and cultural and environmental factors as being important in the formation of mental disorders.
More-modern psychodynamic theories have moved away from the idea of explaining and treating neurosis on the basis of a defect in a single psychological system and have instead adopted a more complex notion of multiple causes, including emotional, psychosexual, social, cultural, and existential ones. A notable trend was the incorporation of approaches derived from theories of learning. Such psychotherapies emphasized the acquired faulty mental processes and maladaptive behavioral responses that act to sustain neurotic symptoms, thereby directing interest toward the patient’s extant circumstances and learned responses to those conditions as a causative factor in mental illness. These approaches marked a convergence of psychoanalytic theory and behavioral theory, especially with regard to each theory’s view of disease causation.
Behavioral etiology
Behavioral theories for the causation of mental disorders, especially neurotic symptoms, are based upon learning theory, which was in turn largely derived from the study of the behavior of animals in laboratory settings. Most important theories in this area arose out of the work of Russian physiologist Ivan Pavlov and several American psychologists, such as Edward L. Thorndike, Clark L. Hull, John B. Watson, Edward C. Tolman, and B.F. Skinner. In the classical Pavlovian model of conditioning, an unconditioned stimulus is followed by an appropriate response; for example, food placed in a dog’s mouth is followed by the dog salivating. If a bell is rung just before food is offered to a dog, eventually the dog will salivate at the sound of the bell only, even though no food is offered. Because the bell could not originally evoke salivation in the dog (and hence was a neutral stimulus) but came to evoke salivation because it was repeatedly paired with the offering of food, it is called a conditioned stimulus. The dog’s salivation at the sound of the bell alone is called a conditioned response. If the conditioned stimulus (the bell) is no longer paired with the unconditioned stimulus (the food), extinction of the conditioned response gradually occurs (the dog ceases to salivate at the sound of the bell alone).
Behavioral theories for the causation of mental disorders rest largely upon the assumption that the symptoms or symptomatic behavior found in persons with various neuroses (particularly phobias and other anxiety disorders) can be regarded as learned behaviors that have been built up into conditioned responses. In the case of phobias, for example, a person who has once been exposed to an inherently frightening situation afterward experiences anxiety even at neutral objects that were merely associated with that situation at the time but that should not reasonably produce anxiety. Thus, a child who has had a frightening experience with a bird may subsequently have a fear response to the sight of feathers. The neutral object alone is enough to arouse anxiety, and the person’s subsequent effort to avoid that object is a learned behavioral response that is self-reinforcing, since the person does indeed procure a reduction of anxiety by avoiding the feared object and is thus likely to continue to avoid it in the future. It is only by confronting the object that the individual can eventually lose the irrational, association-based fear of it.
Major diagnostic categories
Organic mental disorders
This category includes both those psychological or behavioral abnormalities that arise from structural disease of the brain and also those that arise from brain dysfunction caused by disease outside the brain. These conditions differ from those of other mental illnesses in that they have a definite and ascertainable cause—i.e., brain disease. However, the importance of the distinction (between organic and functional) has become less clear as research has demonstrated that brain abnormalities are associated with many psychiatric illnesses. When possible, treatment is aimed at both the symptoms and the underlying physical dysfunction in the brain.
There are several types of psychiatric syndromes that clearly arise from organic brain disease, the chief among them being dementia and delirium. Dementia is a gradual and progressive loss of intellectual abilities such as thinking, remembering, paying attention, judging, and perceiving, without an accompanying disturbance of consciousness. The syndrome may also be marked by the onset of personality changes. Dementia usually manifests as a chronic condition that worsens over the long term. Delirium is a diffuse or generalized intellectual impairment marked by a clouded or confused state of consciousness, an inability to attend to one’s surroundings, difficulty in thinking coherently, a tendency to perceptual disturbances such as hallucinations, and difficulty in sleeping. Delirium is generally an acute condition. Amnesia (a gross loss of recent memory and of time sense without other intellectual impairment) is another specific psychological impairment associated with organic brain disease.
Steps toward the diagnosis of suspected organic disorders include obtaining a full medical history of the patient followed by a detailed examination of the patient’s mental state, with additional tests for particular functions as necessary. A physical examination is also performed with special attention to the central nervous system. In order to determine whether a metabolic or other biochemical imbalance is causing the condition, blood and urine tests, liver function tests, thyroid function tests, and other evaluations may be performed. Chest and skull X-rays may be taken, and computed tomography (CT) scanning or magnetic resonance imaging (MRI) may be used to reveal focal or generalized brain disease. Electroencephalography (EEG) may show localized abnormalities in the electrical conduction of the brain caused by a lesion. Detailed psychological testing may reveal more-specific perceptual, memory, or other disabilities.
Senile and presenile dementia
In these dementias there is a progressive intellectual impairment that proceeds to lethargy, inactivity, and gross physical deterioration and eventually to death within a few years. Presenile dementias are arbitrarily defined as those that begin in persons under age 65. In old age the most common causes of dementia are Alzheimer disease and cerebral arteriosclerosis. Dementia from Alzheimer disease usually begins in people over age 65 and is more common in women than in men. It begins with incidences of forgetfulness, which become more frequent and serious, and the disturbances of memory, personality, and mood progress steadily toward physical deterioration and death within a few years. In dementia caused by cerebral arteriosclerosis, areas of the brain are destroyed through a loss of blood supply caused by pieces of blood clots that become lodged in small arteries. The course of the illness is rapid, with periods of deterioration followed by periods of slight improvement. Death may be delayed slightly longer than with dementia from Alzheimer disease and often occurs from ischemic heart disease, causing a heart attack, or from massive cerebral infarction, causing a stroke.
Other causes of dementia include Pick disease, a rare inherited condition that occurs in women twice as often as in men, usually between the ages of 50 and 60; Huntington disease, an inherited disease that usually begins at about age 40 with involuntary movements and proceeds to dementia and death within 15 years; and Creutzfeldt-Jakob disease, a rare brain condition that is caused by an abnormal form of protein called a prion. Dementia may also result from head injury, infection—e.g., with syphilis or encephalitis—various tumors, toxic conditions such as chronic alcoholism or heavy-metal poisoning, metabolic illnesses such as liver failure, reduced oxygen to the brain due to anemia or carbon monoxide poisoning, and the inadequate intake or metabolism of certain vitamins.
There is no specific treatment for the symptoms of dementia; the underlying physical cause needs to be identified and treated when possible. The goals of care of the individual with dementia are to relieve distress, prevent behavior that might result in injury, and optimize remaining physical and psychological faculties.
Other organic syndromes
Damage to different areas of the brain may cause particular psychological symptoms. Damage to the frontal lobe of the brain may manifest itself in such disturbances of behavior as loss of inhibitions, tactlessness, and overtalkativeness. Lesions of the parietal lobe may result in difficulties of speech and language or of the perception of space. Lesions of the temporal lobe may lead to emotional instability, aggressive behavior, or difficulty with learning new information.
Delirium occurs secondarily to many other physical conditions such as drug intoxication or withdrawal, metabolic disorders (for example, liver failure or low blood sugar), infections such as pneumonia or meningitis, head injuries, brain tumors, epilepsy, or nutritional or vitamin deficiency. Clouding or confusion of consciousness and disturbances of thinking, behavior, perception, and mood occur, with disorientation being prominent. Treatment is aimed at the underlying physical condition.
Substance use disorders
Substance abuse and substance dependence are two distinct disorders associated with the regular nonmedical use of psychoactive drugs. Substance abuse implies a sustained pattern of use resulting in impairment of the person’s social or occupational functioning. Substance dependence implies that a significant portion of a person’s activities are focused on the use of a particular drug or alcohol. Substance dependence likely leads to tolerance, in which markedly increased amounts of a drug (or other addictive substance) must be taken to achieve the same effect. Dependence is also characterized by withdrawal symptoms such as tremors, nausea, and anxiety, any of which might follow decreases in the dose of the substance or the cessation of drug use. (See chemical dependency.)
A variety of psychiatric conditions can result from the use of alcohol or other drugs. Mental states resulting from the ingestion of alcohol include intoxication, withdrawal, hallucinations, and amnesia. Similar syndromes may occur following the use of other drugs that affect the central nervous system (see drug use). Other drugs commonly used nonmedically to alter mood are barbiturates, opioids (e.g., heroin), cocaine, amphetamines, hallucinogens such as LSD (lysergic acid diethylamide), marijuana, and tobacco. Treatment is directed at alleviating symptoms and preventing the patient’s further abuse of the substance.