Selection bias could be an important limiting factor in psychiatric neurobiological research. The study aim was to compare, within an early psychosis program, patients who agreed to participate to neurobiological research with patients who refused.
284 patients with early psychosis were assessed at baseline on a large set of socio-demographic and clinical variables and were followed-up over 36 months.
There were no differences between groups, except regarding forensic/psychiatric history, lifetime substance abuse and social-occupational level during follow-up.
While patients participating to neurobiological research seem representative of our clinical cohort, the few differences identified may deserve attention.