The PRONIA study aims to develop prognostic services for persons at risk of psychosis-related clinical, social and occupational outcomes. A discovery sample included 465 individuals with psychotic or affective illness or at risk for psychosis and 286 healthy controls, between 15 and 40 years from seven sites across Finland, Germany, Italy, Switzerland, and the United Kingdom. A replication dataset acquired by the same consortium included 433 patients and 178 healthy controls from the same seven sites. Baseline assessment began in 2014, and the study was completed in 2019. Participants were recruited from academic early recognition services and screened for eligibility before participating. Follow-up for all patients ranged from 9 to 36 months, with visits every 3 months to the 18-month point and every 9 months thereafter.