MONDAY, Oct. 24, 2005 (HealthDay News) -- Heredity seems to play a major role in schizophrenia, since the disease runs in families, and now new research sheds light on exactly how a genetic mutation disrupts the brain and makes people develop the condition.
The findings could eventually result in better drugs for schizophrenia, which is difficult to treat. For now, however, they're helping scientists understand the development of the disease, said Dr. Doron Gothelf, a child psychiatrist at Stanford University and co-author of a study in the Oct. 23 online issue of Nature Neuroscience.
Schizophrenics -- an estimated 1 percent of the population -- have trouble comprehending reality and are often prone to hallucinations and delusions. Some schizophrenics have memory and thinking problems, too.
"It's a disorder of thought," explained Wendy R. Kates, an associate professor of psychiatry at the State University of New York Upstate Medical University. "People hear voices that aren't necessarily there, and they experience delusions."
However, contrary to depictions in movies and on television, schizophrenia and multiple-personality disorder -- now known as dissociative identity disorder -- are different conditions.
According to Gothelf, schizophrenia appears to be inherited about 70 percent of the time, with a small percentage of schizophrenia cases connected to a gene mutation in one of the body's two copies of the 22nd chromosome. About 30 percent of children with the rare mutation become schizophrenic or develop another psychotic disorder; some have unusual facial features and cleft problems that make their speech very nasal.
According to Gothelf, "we wanted to know why one-third develop schizophrenia, and two-thirds do not."
Gothelf and a team of American and Swiss researchers studied 24 young children who had the genetic mutation to figure out why it causes schizophrenia. Then they checked on the children five years later when they were adolescents; schizophrenia often develops in young adulthood.
In the new study, the researchers report that seven of the children developed psychotic disorders. The worst cases of cognitive difficulties -- such as the inability to think clearly -- were among those whose brains had the most difficulty processing the neurotransmitter chemical known as dopamine.
Scientists have linked dopamine to a variety of emotions, including desire and pleasure, along with memory and the ability to plan and organize.
The findings could lead to genetic screening for schizophrenia among children, Kates said. But there's controversy over whether to give drugs to those children or wait until they have symptoms, she said. "At the very least, though, (the patient) can be monitored, and the family and patient can be given more support."
What this mean in terms of changes in medical treatment? Currently, schizophrenics are treated with anti-psychotic drugs, but they aren't always effective.
Gothelf said the future on the drug front isn't clear. "In general, in psychology the path from genes to biochemistry to a new medication is not straightforward," he said.
Learn more about schizophrenia from the online encyclopedia Wikipedia.