The Philadelphia Neurodevelopmental Cohort: Perspective, Lessons, and Future Directions.

The Philadelphia Neurodevelopmental Cohort (PNC), a response to an NIMH request for applications to stimulate the economy has mobilized Penn-CHOP investigators to rise to this Grand Opportunity and do what seemed to be unthinkable. In a 2-year period (2009-2011), we established and trained research teams, conducted an in-person assessment of psychopathology, and administered a computerized neurocognitive battery to about 10,000 genotyped youth ages 8-21, with a subsample of about 1600 undergoing multimodal neuroimaging. Over a decade later, with the field moving forward to large-scale collaborative projects, and us building on the PNC in longitudinal studies, we provide a perspective on the rationale that guided our decisions, the tools, and procedures developed for the implementation of data collection, the rigorous process of ensuring high data quality, and data sharing. We highlight the experience and lessons learned: What could we have done better or differently? We feature the importance of access to electronic health records, gaining a developmental perspective, and sample diversity. Given our interest in the psychosis spectrum (PS), special emphasis will relate to multimodal measurements of youths with PS features. In this issue, we present some key PNC findings, that relate to brain development and PS, highlighted within the context of reported findings from other studies in community-based cohorts, help-seeking youth at risk for psychosis, and those early in the course of schizophrenia spectrum disorders. Building on the PNC, we summarize future opportunities for longitudinal and intergenerational investigation.