However, this loss of what is called brain volume does not worsen schizophrenia symptoms or affect overall mental function, researchers reported in the study published online July 18 in the journal PLoS One.
"It's important to stress that the loss of brain volume doesn't appear to have any effect on people over the nine-year follow-up we conducted, and patients should not stop their medication on the basis of this research," study author Dr. Graham Murray, of the Behavioral and Clinical Neuroscience Institute and the department of psychiatry at the University of Cambridge in England, said in a university news release.
"A key question in future will be to examine whether there is any effect of this loss of brain volume later in life. We need more research in larger studies with longer follow-ups to evaluate the significance of these brain changes," he added.
All people naturally lose some brain volume as they age, but schizophrenia patients lose brain volume at a faster rate. The reasons for this difference aren't known, but it's been suggested that the antipsychotic medications taken by schizophrenia patients may be a factor.
This study included 33 schizophrenia patients and a "control" group of 71 people without the disorder who had a series of brain scans over nine years, from ages 34 to 43. The schizophrenia patients lost 0.7 percent of brain volume a year, compared with 0.5 percent among those in the control group, the findings showed.
The rate of brain volume loss among schizophrenia patients was greater when their dose of antipsychotic medication was higher, the investigators found. However, this association does not prove that the medications actually caused this loss of brain volume.
The researchers also examined, but found no evidence of, any link between the amount of brain volume loss and the severity of schizophrenia symptoms or reduced mental function.
The U.S. National Institute of Mental Health has more about schizophrenia.