This paper describes a cohort study of young people identified as being at high risk of incipient first episode of psychosis using clearly defined clinical criteria. We followed up this cohort of 49 subjects for 12 months and found that over 40% had first onset of a psychotic disorder within that time frame. Thus at the time of initial recruitment into the study (with the benefit of hindsight) these people were in the prodromal phase of a psychotic disorder, as we had hypothesized. We were able to track the onset phase by monthly follow-up. This was an exciting finding as it means that by using our criteria for "ultra high risk" (UHR) status, researchers can investigate the process of onset of psychotic disorders such as schizophrenia. Neurobiological, psychophysiological, neuropsychological, and psychosocial mechanisms which underlie and contribute to the manifestation of frank psychotic symptoms in the early stages of illness can be elucidated, and theories of onset of disorders such as schizophrenia can be refined. Our findings also create a platform for examining the possibility of delay, amelioration or even prevention of onset of frank psychotic symptoms through preventative interventions in people meeting the UHR criteria. Thus our paper has been widely cited by other researchers who are replicating the findings and by researchers who are using our discoveries as a basis for their own projects.

The methodology we employed to identify a group with a high likelihood of onset of psychotic disorder within a brief follow-up period is easily applied by others and opens up many other research possibilities in the field of etiological and intervention research. Our criteria have been adopted and adapted by several research centers around the world.

We developed a clinical service (called the PACE Clinic) and follow-up system for young people we thought were at high risk of developing a psychotic disorder, such as schizophrenia, within the near future. We saw these individuals monthly and tried to treat their symptoms. Over 40% developed a psychotic disorder within one year, which means that they truly were at high risk when we first saw them. This research has been the basis of other research which tries to prevent the worsening of their symptoms. Research into what makes deterioration more or less likely and the best way to help these people is now underway around the world.

As a young doctor training in psychiatry, I noticed that most patients with schizophrenia whose care I was managing described a prodromal phase leading up to the first full blown manifestation of illness. It was frustrating to think that their illnesses could have been identified earlier and maybe some of their suffering prevented or at least reduced. I started in the field of early identification about 10 years ago, initially trying to build a picture of the typical onset pattern. I then turned this into a method for prospective recognition and developed the criteria and follow-up system which is described in this paper.

Alison Yung, M.D., M.P.M., FRANZCP
Associate Professor and Principal Research Fellow
ORYGEN Youth Research Centre
The University of Melbourne Department of Psychiatry
Medical Director, PACE Clinic
Parkville, Victoria, Australia