Schizophrenia, a chronic and debilitating disorder marked in part by auditory hallucinations and paranoia, can strike in late adolescence or early adulthood at a time when people are ready to stand on their own two feet as fully independent adults.
Now scientists at UCLA think they are beginning to understand one important piece of this puzzle. In the first study of its kind, the researchers used a novel form of brain imaging to discover that white matter in the brains of adolescents at risk of developing schizophrenia does not develop at the same rate as healthy people. Further, the extent of these alterations can be used to predict how badly patients will or will not deteriorate functionally over time.
Reporting in the online edition of the journal Biological Psychiatry, lead author Katherine Karlsgodt, a postdoctoral fellow in UCLA's Department of Psychology, and senior authors Tyrone Cannon and Carrie Bearden, professors at the UCLA Semel Institute for Neuroscience and Human Behavior, focused on the brain's white matter - which forms the major connections between different brain regions - because it is known that white matter is disrupted in people who already have schizophrenia.
"We found that healthy subjects showed a normal and expected increase in measures indexing white matter integrity in the temporal lobe as they age," said Karlsgodt, "but young people at high-risk for psychosis showed no such increase - that is, they fail to show the normal developmental pattern."
While there is growing evidence that schizophrenics show changes in white matter, and there is increasing evidence that white matter connectivity may be highly relevant to the development of psychosis, there is very little known about how these changes arise, said Karlsgodt. Historically, looking at white matter has been hard to do. But in recent years, she said, researchers have begun to use a relatively new technique, diffusion tensor imaging (DTI) that uses the movement of water molecules along white matter tracts to map out the brain's pathways. In the last few years, these techniques have been applied to research schizophrenia and other disorders.