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Pharmacology => Drug => Schizophrenia
Schizophrenia
INTRODUCTION
Schizophrenia, severe mental illness characterized by a variety of symptoms, including loss of contact with reality, bizarre behavior, disorganized thinking and speech, decreased emotional expressiveness, and social withdrawal. Usually only some of these symptoms occur in any one person. The term schizophrenia comes from Greek words meaning "split mind." However, contrary to common belief, schizophrenia does not refer to a person with a split personality or multiple personality. To observers, schizophrenia may seem like madness or insanity.
Perhaps more than any other mental illness, schizophrenia has a debilitating effect on the lives of the people who suffer from it. A person with schizophrenia may have difficulty telling the difference between real and unreal experiences, logical and illogical thoughts, or appropriate and inappropriate behavior. Schizophrenia seriously impairs a person's ability to work, go to school, enjoy relationships with others, or take care of oneself. In addition, people with schizophrenia frequently require hospitalization because they pose a danger to themselves. About 10 percent of people with schizophrenia commit suicide, and many others attempt suicide. Once people develop schizophrenia, they usually suffer from the illness for the rest of their lives. Although there is no cure, treatment can help many people with schizophrenia lead productive lives.
Schizophrenia also carries an enormous cost to society. People with schizophrenia occupy about one-third of all beds in psychiatric hospitals in the United States. In addition, people with schizophrenia account for at least 10 percent of the homeless population in the United States . The National Institute of Mental Health has estimated that schizophrenia costs the United States tens of billions of dollars each year in direct treatment, social services, and lost productivity.
PREVALENCE
Approximately 1 percent of people develop schizophrenia at some time during their lives. Experts estimate that about 1.8 million people in the United States have schizophrenia. The prevalence of schizophrenia is the same regardless of gender, race, and culture. Although women are just as likely as men to develop schizophrenia, women tend to experience the illness less severely, with fewer hospitalizations and better social functioning in the community.
SYMPTOMS
Schizophrenia usually develops in late adolescence or early adulthood, between the ages of 15 and 30. Much less commonly, schizophrenia develops later in life. The illness may begin abruptly, but it usually develops slowly over months or years. Mental health professionals diagnose schizophrenia based on an interview with the patient in which they determine whether the person has experienced specific symptoms of the illness.
Symptoms and functioning in people with schizophrenia tend to vary over time, sometimes worsening and other times improving. For many patients the symptoms gradually become less severe as they grow older. About 25 percent of people with schizophrenia become symptom-free later in their lives.
A variety of symptoms characterize schizophrenia. The most prominent include symptoms of psychosis-such as delusions and hallucinations-as well as bizarre behavior, strange movements, and disorganized thinking and speech. Many people with schizophrenia do not recognize that their mental functioning is disturbed.
° Delusions
Delusions are false beliefs that appear obviously untrue to other people. For example, a person with schizophrenia may believe that he is the king of England when he is not. People with schizophrenia may have delusions that others, such as the police or the FBI, are plotting against them or spying on them. They may believe that aliens are controlling their thoughts or that their own thoughts are being broadcast to the world so that other people can hear them.
° Hallucinations
People with schizophrenia may also experience hallucinations (false sensory perceptions). People with hallucinations see, hear, smell, feel, or taste things that are not really there. Auditory hallucinations, such as hearing voices when no one else is around, are especially common in schizophrenia. These hallucinations may include two or more voices conversing with each other, voices that continually comment on the person's life, or voices that command the person to do something.
° Bizarre
Behavior People with schizophrenia often behave bizarrely. They may talk to themselves, walk backward, laugh suddenly without explanation, make funny faces, or masturbate in public. In rare cases, they maintain a rigid, bizarre pose for hours on end. Alternately, they may engage in constant random or repetitive movements.
° Disorganized Thinking and Speech
People with schizophrenia sometimes talk in incoherent or nonsensical ways, which suggests confused or disorganized thinking. In conversation they may jump from topic to topic or string together loosely associated phrases. They may combine words and phrases in meaningless ways or make up new words. In addition, they may show poverty of speech, in which they talk less and more slowly than other people, fail to answer questions or reply only briefly, or suddenly stop talking in the middle of speech.
° Social Withdrawal
Another common characteristic of schizophrenia is social withdrawal. People with schizophrenia may avoid others or act as though others do not exist. They often show decreased emotional expressiveness. For example, they may talk in a low, monotonous voice, avoid eye contact with others, and display a blank facial expression. They may also have difficulties experiencing pleasure and may lack interest in participating in activities.
° Other Symptoms
Other symptoms of schizophrenia include difficulties with memory, attention span, abstract thinking, and planning ahead. People with schizophrenia commonly have problems with anxiety, depression, and suicidal thoughts. In addition, people with schizophrenia are much more likely to abuse or become dependent upon drugs or alcohol than other people. The use of alcohol and drugs often worsens the symptoms of schizophrenia, resulting in relapses and hospitalizations.
CAUSES
Schizophrenia appears to result not from a single cause, but from a variety of factors. Most scientists believe that schizophrenia is a biological disease caused by genetic factors, an imbalance of chemicals in the brain, structural brain abnormalities, or abnormalities in the prenatal environment. In addition, stressful life events may contribute to the development of schizophrenia in those who are predisposed to the illness.
° Genetic Factors
Research suggests that the genes one inherits strongly influence one's risk of developing schizophrenia. Studies of families have shown that the more closely one is related to someone with schizophrenia, the greater the risk one has of developing the illness. For example, the children of one parent with schizophrenia have about a 13 percent chance of developing the illness, and children of two parents with schizophrenia have about a 46 percent chance of eventually developing schizophrenia. This increased risk occurs even when such children are adopted and raised by mentally healthy parents. In comparison, children in the general population have only about a 1 percent chance of developing schizophrenia.
° Chemical Imbalance
Some evidence suggests that schizophrenia may result from an imbalance of chemicals in the brain called neurotransmitters. These chemicals enable neurons (brain cells) to communicate with each other. Some scientists suggest that schizophrenia results from excess activity of the neurotransmitter dopamine in certain parts of the brain or from an abnormal sensitivity to dopamine. Support for this hypothesis comes from antipsychotic drugs, which reduce psychotic symptoms in schizophrenia by blocking brain receptors for dopamine. In addition, amphetamines, which increase dopamine activity, intensify psychotic symptoms in people with schizophrenia. Despite these findings, many experts believe that excess dopamine activity alone cannot account for schizophrenia. Other neurotransmitters, such as serotonin and norepinephrine, may play important roles as well.
deg; Structural Brain
Abnormalities Brain imaging techniques, such as magnetic resonance imaging and positron-emission tomography, have led researchers to discover specific structural abnormalities in the brains of people with schizophrenia. For example, people with chronic schizophrenia tend to have enlarged brain ventricles (cavities in the brain that contain cerebrospinal fluid). They also have a smaller overall volume of brain tissue compared to mentally healthy people. Other people with schizophrenia show abnormally low activity in the frontal lobe of the brain, which governs abstract thought, planning, and judgment. Research has identified possible abnormalities in many other parts of the brain, including the temporal lobes, basal ganglia, thalamus, hippocampus, and superior temporal gyrus. These defects may partially explain the abnormal thoughts, perceptions, and behaviors that characterize schizophrenia.
° Prenatal Factors
Evidence suggests that factors in the prenatal environment can increase the risk of a person later developing schizophrenia. For example, pregnant women who have been exposed to the influenza virus or who have poor nutrition have a slightly increased chance of giving birth to a child who later develops schizophrenia.
° Stressful Events
Although scientists favor a biological cause of schizophrenia, stress in the environment may affect the onset and course of the illness. Stressful life circumstances-such as the death of a loved one, an important change in jobs or relationships, or chronic tension and hostility at home-can increase the chances of schizophrenia in a person biologically predisposed to the disease. In addition, stressful events can trigger a relapse of symptoms in a person who already has the illness. Individuals who have effective skills for managing stress may be less susceptible to its negative effects.
TREATMENT
Although there is no cure for schizophrenia, effective treatment exists that can improve the long-term course of the illness. Most physicians use antipsychotic drugs (also called neuroleptics) to treat people with schizophrenia. Skills training and rehabilitation programs may also help people with this illness function in the community.
° Antipsychotic Drugs
Antipsychotic medications, discovered in the mid-1950s, can dramatically improve the quality of life for people with schizophrenia. The drugs reduce or eliminate psychotic symptoms such as hallucinations and delusions. The medications can also help prevent these symptoms from returning. Common antipsychotic drugs include haloperidol (Haldol), risperidone (Risperdal), olanzapine (Zyprexa), thioridazine (Mellaril), clozapine (Clozaril), chlorpromazine (Thorazine), fluphenazine (Prolixin), and trifluoperazine (Stelazine). People with schizophrenia usually must take medication for the rest of their lives to control psychotic symptoms. Antipsychotic medications appear to be less effective at treating other symptoms of schizophrenia, such as social withdrawal and apathy.
Antipsychotic drugs help reduce symptoms in 80 to 90 percent of people with schizophrenia. However, those who benefit often stop taking medication because they do not understand that they are ill or because of unpleasant side effects. Minor side effects include dry mouth, blurred vision, constipation, dizziness, and drowsiness. Other side effects are more serious and debilitating. These may include muscle spasms or cramps, tremors, and tardive dyskinesia, an irreversible condition marked by uncontrollable movements of the lips, mouth, and tongue. Newer drugs, such as clozapine, olanzapine, and risperidone, produce fewer of these side effects. However, clozapine can cause agranulocytosis, a sometimes fatal blood disease. For this reason, people taking clozapine must have weekly tests to monitor their blood.
° Skills Training and Rehabilitation
Because many patients with schizophrenia continue to experience difficulties despite taking medication, other types of treatment are often necessary. Social skills training helps people with schizophrenia learn specific behaviors for functioning in society such as making friends, purchasing items at a store, or initiating conversations. Behavioral training methods can also help them learn self-care skills such as personal hygiene, money management, and proper nutrition.
Family intervention programs can also benefit people with schizophrenia. These programs focus on helping family members understand the nature and treatment of schizophrenia, how to monitor the illness, and how to create a low-stress environment that helps patients make progress towards greater independence. Because many patients have difficulty obtaining or keeping jobs, employment programs that help patients find and maintain jobs are a helpful part of rehabilitation. Despite the severity of schizophrenia, treatment that combines medication and rehabilitation can improve the long-term prospects for people with this mental illness.
RELATED DISORDERS
Several other psychiatric disorders are closely related to schizophrenia. In schizoaffective disorder, a person shows symptoms of schizophrenia combined with either mania or severe depression. Schizophreniform disorder refers to an illness in which a person experiences schizophrenic symptoms for more than one month but fewer than six months. In schizotypal personality disorder, a person engages in odd thinking, speech, and behavior, but usually does not lose contact with reality . Sometimes mental health professionals refer to these disorders together as schizophrenia-spectrum disorders.
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