An overview and history of the NAPLS Consortium
Despite treatment advances, schizophrenia and other psychotic disorders remain seriously disabling, life-long illnesses. As a result, in parallel with other chronic physical illnesses, such as diabetes and heart disease, the scientific focus has recently begun to shift to early intervention and prevention. In the field of schizophrenia, this focus has generated an interest in the prodromal phase of illness, the stage just prior to florid psychosis. Subtle pre-illness clinical, psychosocial and neurocognitive deficits have been reported for many years, but only in the past decade has systematic, reliable identification of “prodromal” individuals become possible, based on the presence of subthreshold psychotic symptoms and/or a family history of schizophrenia with signs of functional deterioration. Such “clinical high risk” (CHR) individuals have high rates of conversion to psychosis (ranging from 20-50% in most studies) over about two years.
Prodromal studies to date have been substantially limited by small sample sizes and lack of attention to biological mechanisms. As a way to overcome these shortcomings, in 2003 we initiated the North American Prodrome Longitudinal Study (NAPLS); a consortium of eight independent NIMH-funded prodromal studies located at Emory University, Harvard University, University of California Los Angeles (UCLA), University of California San Diego (UCSD), University of North Carolina Chapel Hill, University of Toronto, Yale University, and Zucker Hillside Hospital. The consortium combined previously collected prospective, longitudinal data from these eight sites into a common federated database including 291 prodromal individuals, 35% of whom converted to psychosis within 2½ years. A combined clinical profile index predicted conversion to psychosis over a 2½-year follow-up with approximately 80% positive predictive validity (Cannon et al., 2008).
In 2008, the NAPLS consortium was awarded a 5-year, $23 million grant from the National Institute of Mental Health to incorporate biological assessment approaches (neuroimaging, electrophysiological, hormonal and genomics) into a multi-site prospective, longitudinal study of 720 prodromal patients and 240 matched healthy controls. At that time, the NIMH converted the grant from a Collaborative R01 to a Collaborative U01, and the University of Calgary replaced the University of Toronto as one of the sites.