Schizophrenia: An Overview
What Causes Schizophrenia?
The exact cause of schizophrenia is not yet known. It is known, however, that schizophrenia -- like cancer and diabetes -- is a real illness with a biological basis. It is not the result of bad parenting or personal weakness. Researchers have uncovered a number of factors that appear to play a role in the development of schizophrenia, including:
- Genetics (heredity): Schizophrenia tends to run in families, which means a greater likelihood to develop schizophrenia may be passed on from parents to their children.
- Brain chemistry: People with schizophrenia may have an imbalance of certain chemicals in the brain. They may be either very sensitive to or produce too much of a brain chemical called dopamine. Dopamine is a neurotransmitter, a substance that helps nerve cells in the brain send messages to each other. An imbalance of dopamine affects the way the brain reacts to certain stimuli, such as sounds, smells, and sights and can lead to hallucinations and delusions.
- Brain abnormality: Research has found abnormal brain structure and function in people with schizophrenia. However, this type of abnormality doesn't happen in all schizophrenics and can occur in people without the disease.
- Environmental factors: Evidence suggests that certain environmental factors, such as a viral infection, extensive exposure to toxins like marijuana, or highly stressful situations, may trigger schizophrenia in people who have inherited a tendency to develop the disorder. Schizophrenia more often surfaces when the body is undergoing hormonal and physical changes, such as those that occur during the teen and young adult years.
Who Gets Schizophrenia?
Anyone can get schizophrenia. It is diagnosed all over the world and in all races and cultures. While it can occur at any age, schizophrenia typically first appears in the teenage years or early 20s. The disorder affects men and women equally, although symptoms generally appear earlier in men (in their teens or 20s) than in women (in their 20s or early 30s). Earlier onset of symptoms has been linked to a more severe course of illness. Children over the age of 5 can develop schizophrenia, but it is very rare before adolescence.
How Common Is Schizophrenia?
Schizophrenia occurs in about 1% of the population. About 2.2 million Americans, ages 18 and older, will develop schizophrenia.
How Is Schizophrenia Diagnosed?
If symptoms of schizophrenia are present, the doctor will perform a complete medical history and physical exam. While there are no laboratory tests to specifically diagnose schizophrenia, the doctor may use various tests, such as X-rays and blood tests, to rule out a physical illness or intoxication (substance-induced psychosis) as the cause of the symptoms.
If the doctor finds no physical reason for the schizophrenia symptoms, he or she may refer the person to a psychiatrist or psychologist, mental health professionals who are specially trained to diagnose and treat mental illnesses. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a psychotic disorder. The therapist bases his or her diagnosis on the person's report of symptoms and his or her observation of the person's attitude and behavior. A person is considered to have schizophrenia if he or she has characteristic symptoms that last for at least six months.