Schizophrenic children have slower brain growth, a government study found.

Kids with schizophrenia had growth of 1.3 percent a year in their brain's white matter compared with 2.6 percent growth in normal children, according to the study published in the Proceedings of the National Academy of Sciences. White matter is the tissue nerve cells use to send messages in the brain.

Previous studies had shown that gray matter, which is the part of nerve cells responsible for processing signals, also grows more slowly in schizophrenic patients.

"What we've done is studied these children long-term, and the early brain findings eventually merge into the same pattern we've seen in adults,'' said Nitin Gogtay, the study's lead author and a researcher for the National Institutes of Health in Bethesda, Maryland, in a telephone interview on Oct. 10. "Whatever happens to start it, the illness brings all these changes.''

The schizophrenic children also had slower growth in the right hemisphere of the brain, which controls visual and intuitive information, the study found.

The scientists scanned the brains of 12 children diagnosed with schizophrenia, and matched them with scans of 12 healthy children. Scans took place over the course of 5 years. Although the growth rates were reduced in the schizophrenic children, it wasn't due to a lower IQ, the researchers found.

1 Percent

Schizophrenia affects in about 1 percent of Americans over the age of 18, usually developing in patients' late teens and early twenties, according to the National Institute of Mental Health. Symptoms include hallucinations and paranoia, and about 10 percent of schizophrenics commit suicide.

Children who manifest mental illness before the age of 13 have a more severe form of the disease, and childhood schizophrenia is rare, according to the Mayo Clinic. By studying children who are diagnosed early, the researchers have side- stepped possible complicating factors, like drug abuse, which is common in schizophrenia patients.

Schizophrenic Smokers

A separate study in the same journal found more evidence that nicotine may help lessen the hallucinations associated with schizophrenia, according to a mouse model. The finding may explain why many schizophrenic adults smoke cigarettes heavily, perhaps as a way to self-medicate.

The study showed how nicotine boosts the levels of a brain chemical, GABA, which is unusually low in schizophrenia patients. Although nicotine was known to affect brain chemistry by increasing the function of this chemical, the exact mechanism has remained unclear until now.

Scientists don't know what causes the lowered levels of GABA and slowed growth of brain matter, Gogtay said. His research may help scientists focus their search.

"What we are trying to do is to look more carefully at other factors that can influence both gray and white matter,'' Gogtay said. "Those who are better-functioning schizophrenics seem to have better rates of growth.''