What is schizophrenia?
Schizophrenia is a chronic, severe, and disabling brain disorder that has affected people throughout history. About 1 percent of Americans have this illness.1

People with the disorder may hear voices other people don't hear. They may believe other people are reading their minds, controlling their thoughts, or plotting to harm them. This can terrify people with the illness and make them withdrawn or extremely agitated.

People with schizophrenia may not make sense when they talk. They may sit for hours without moving or talking. Sometimes people with schizophrenia seem perfectly fine until they talk about what they are really thinking.

Families and society are affected by schizophrenia too. Many people with schizophrenia have difficulty holding a job or caring for themselves, so they rely on others for help.

Treatment helps relieve many symptoms of schizophrenia, but most people who have the disorder cope with symptoms throughout their lives. However, many people with schizophrenia can lead rewarding and meaningful lives in their communities. Researchers are developing more effective medications and using new research tools to understand the causes of schizophrenia. In the years to come, this work may help prevent and better treat the illness.

When does schizophrenia start and who gets it?
Schizophrenia affects men and women equally. It occurs at similar rates in all ethnic groups around the world. Symptoms such as hallucinations and delusions usually start between ages 16 and 30. Men tend to experience symptoms a little earlier than women. Most of the time, people do not get schizophrenia after age 45.3 Schizophrenia rarely occurs in children, but awareness of childhood-onset schizophrenia is increasing.4,5

It can be difficult to diagnose schizophrenia in teens. This is because the first signs can include a change of friends, a drop in grades, sleep problems, and irritability—behaviors that are common among teens. A combination of factors can predict schizophrenia in up to 80 percent of youth who are at high risk of developing the illness. These factors include isolating oneself and withdrawing from others, an increase in unusual thoughts and suspicions, and a family history of psychosis.6 In young people who develop the disease, this stage of the disorder is called the "prodromal" period.

What causes schizophrenia?
Experts think schizophrenia is caused by several factors.

Genes and environment. Scientists have long known that schizophrenia runs in families. The illness occurs in 1 percent of the general population, but it occurs in 10 percent of people who have a first-degree relative with the disorder, such as a parent, brother, or sister. People who have second-degree relatives (aunts, uncles, grandparents, or cousins) with the disease also develop schizophrenia more often than the general population. The risk is highest for an identical twin of a person with schizophrenia. He or she has a 40 to 65 percent chance of developing the disorder.15

We inherit our genes from both parents. Scientists believe several genes are associated with an increased risk of schizophrenia, but that no gene causes the disease by itself.16 In fact, recent research has found that people with schizophrenia tend to have higher rates of rare genetic mutations. These genetic differences involve hundreds of different genes and probably disrupt brain development.17

Other recent studies suggest that schizophrenia may result in part when a certain gene that is key to making important brain chemicals malfunctions. This problem may affect the part of the brain involved in developing higher functioning skills.18 Research into this gene is ongoing, so it is not yet possible to use the genetic information to predict who will develop the disease.

Despite this, tests that scan a person's genes can be bought without a prescription or a health professional's advice. Ads for the tests suggest that with a saliva sample, a company can determine if a client is at risk for developing specific diseases, including schizophrenia. However, scientists don't yet know all of the gene variations that contribute to schizophrenia. Those that are known raise the risk only by very small amounts. Therefore, these "genome scans" are unlikely to provide a complete picture of a person's risk for developing a mental disorder like schizophrenia.

In addition, it probably takes more than genes to cause the disorder. Scientists think interactions between genes and the environment are necessary for schizophrenia to develop. Many environmental factors may be involved, such as exposure to viruses or malnutrition before birth, problems during birth, and other not yet known psychosocial factors.

How is schizophrenia treated?
Because the causes of schizophrenia are still unknown, treatments focus on eliminating the symptoms of the disease. Treatments include antipsychotic medications and various psychosocial treatments.

Antipsychotic medications
Antipsychotic medications have been available since the mid-1950's. The older types are called conventional or "typical" antipsychotics. Some of the more commonly used typical medications include:

• Chlorpromazine (Thorazine)
• Haloperidol (Haldol)
• Perphenazine (Etrafon, Trilafon)
• Fluphenazine (Prolixin).

One of these medications, clozapine (Clozaril) is an effective medication that treats psychotic symptoms, hallucinations, and breaks with reality. But clozapine can sometimes cause a serious problem called agranulocytosis, which is a loss of the white blood cells that help a person fight infection. People who take clozapine must get their white blood cell counts checked every week or two. This problem and the cost of blood tests make treatment with clozapine difficult for many people. But clozapine is potentially helpful for people who do not respond to other antipsychotic medications.19

Other atypical antipsychotics were also developed. None cause agranulocytosis. Examples include.

• Risperidone (Risperdal)
• Olanzapine (Zyprexa)
• Quetiapine (Seroquel)
• Ziprasidone (Geodon)
• Aripiprazole (Abilify)
• Paliperidone (Invega).