Jan. 7, 2008 -- New research could help doctors identify troubled teens who will develop psychotic illness with a high degree of accuracy.
Researchers were able to predict psychosis before the onset of full-blown psychotic episodes in roughly a third of patients, based on widely accepted criteria for risk.
When patients exhibited a specific combination of risk factors, as many as 80% were identified within two and a half years of being diagnosed with schizophrenia or another psychotic disorder.
Patients with early symptoms indicative of psychosis, such as unusual thoughts or a high level of paranoia, had a very high likelihood of progressing to full-blown psychosis within just a few years if they also had a family history of psychotic disease and had recently experienced a dramatic decline in social functioning, says study researcher Tyrone D. Cannon, PhD, of the University of California, Los Angeles.
A sudden drop in grades or a general inability to function normally and abuse of drugs or alcohol were also among the risk factors included in a predictive model developed by Cannon and colleagues.
"When a kid who is pretty connected with his peers and doing well at school suddenly withdraws and is having unusual thoughts or becomes highly suspicious, it should not be ignored," Cannon tells WebMD.
(Do you think it would help to know ahead of time if your child was at risk for mental illness? Tell us about it on the Depressed & Bipolar Kids: Family Support board.)
Risk Factors for Psychosis
Cannon, co-author Robert Heinssen, PhD, of the National Institute of Mental Health (NIMH), and colleagues from seven other research centers recruited 291 high-risk teens for their study.
The teenagers were considered high risk because they had symptoms associated with psychosis but did not have a diagnosis of a psychotic disorder.
If a participant had an unrealistic belief that they were being watched, for example, but could be shown that their troubling thoughts were unfounded, that participant was considered to have a risk factor for psychotic illness but not the disorder itself.
The same participant would be considered to have crossed the threshold to full-blown psychosis if he or she were unable to recognize paranoid thoughts for what they are or are disabled by them.
Cannon says other changes in perception, such as hearing buzzing or crackling sounds or seeing images that quickly disappear, often predict the imminent onset of psychosis.
Among the study participants, 35% who exhibited one risk factor identified in the predictive model developed a psychotic illness within 30 months. Those who had two or three additional risk factors developed psychosis within the same time period 68% to 80% of the time.
The NIMH-funded study is published in the January issue of the Archives of General Psychiatry.
Earlier Treatment, Better Outcomes
If the findings are confirmed, the prediction model could help doctors identify those at risk for psychotic illness much sooner so that these people can be monitored closely for signs of active psychosis.
That is important because early treatment with antipsychotic drugs has been shown to be associated with much more favorable outcomes, Heinssen tells WebMD.
But no one is suggesting that the drugs be used in patients who have not yet developed active psychosis.
"Treatment should begin as soon as a person crosses that threshold from pre-psychosis to active psychosis," Heinssen says. "But active psychosis is often present for weeks and even months before drugs are given."
Cannon, Heinssen, and colleagues also hope to move beyond symptoms to identify biological markers that indicate a high risk for psychotic illness.
Studies are planned or are under way examining the chemical changes within the brain, hormonal changes, and changes in cognitive function in people with psychotic disease.
Just as cholesterol and blood pressure are now used to assess heart disease risk, these measures may one day help physicians determine someone's risk for psychosis, Cannon and Heinssen tell WebMD.