(RxWiki News) The process of identifying people at very high risk for schizophrenia is getting better. But it can still be hard to know who will actually go on to develop full psychosis.
Most people are identified as high risk when they are young, under age 30. Individuals are most likely to develop full psychosis during their late teens or early 20s.
A recent study found that the most important time to watch for patients becoming fully psychotic is in the first two years after they are identified as high risk.
However, they could still go on to develop psychosis as long as ten years after being identified.
"Seek help if you experience possible schizophrenia symptoms."
The study, led by Barnaby Nelson, PhD, of the Orygen Youth Health Research Centre at the University of Melbourne in Australia, looked at the long-term rates of psychosis in patients at high risk for schizophrenia.
The researchers followed 416 patients, aged 15 to 30 when they started the study, who had been identified as being at "ultra high risk" for developing psychosis.
Developing psychosis means the patients experience the full symptoms of schizophrenia. It was defined as "at least one fully positive psychotic symptom several times a week for more than one week."
A person is identified as ultra high risk if they meet one of three criteria:
- They have weakened psychotic symptoms
- They experience brief and intermittent psychotic symptoms that go away on their own
- They experience a significant decrease in their ability to function and are genetically at risk for schizophrenia because they have a very close relative with a psychotic disorder or because they have a schizotypal personality disorder
Recent research has found that fewer ultra high risk patients appear to be developing psychosis in the short-term, within one to two years.
However, it's not clear whether rates are actually going down or whether people are being identified as ultra high risk earlier on, so more time goes by before they develop psychosis.
Therefore this study followed the patients long-term, for an average of 7.5 years, to see which patients transitioned to psychotic disorder.
About a third of the patients were followed for at least 10 years, and the longest follow-up was 15 years.
The researchers hoped the longer term study would help them learn more accurately what the risk is for patients developing full psychosis and what might predict that transition.
Of the total group, about 35 percent (114 patients) developed a psychotic disorder.
The highest rate of transition to full psychosis occurred in the first two years of follow-up, when 20 percent of the patients transitioned.
However, the last transition to occur happened 9.7 years after the patient began the study.
The researchers found that experiencing symptoms of schizophrenia for a longer period of time before starting the study increased a person's risk of transitioning to psychosis.
Each additional year that the patient had experienced symptoms before going to the clinic, the risk of developing psychosis increased by 12 percent.
Another risk factor for going on to develop full psychosis was having poor functioning when the patient started the study. The cut-off for poor functioning was a score of 44 or lower on the Global Assessment of Functioning (GAF) scale (a scale of 0 to 100).
A patient with a 44 or lower GAF score and/or who had experienced symptoms for at least two years before visiting the clinic had a 72 percent chance of developing psychosis within five years.
Those who had a GAF score above 44 and experienced symptoms for less than two years before visiting the clinic had a 69 percent chance of not developing psychosis within five years.
The researchers also concluded that a person may develop psychosis up to 10 years after being identified as ultra high risk, but their highest risk is in the first two years after being identified.
This finding "...indicates that the period of clinical care for ultra high risk patients should be at least two years, with the possibility of reentry to services after this point if required," the researchers wrote.
The study was published June 5 in JAMA Psychiatry.
The research was funded by the National Health and Medical Research Council Program and the Colonial Foundation. The authors declared no conflicts of interest.