RecruitingBehavioural interventionDeveloping Biomarker-Supported Schizophrenia Spectrum Disorder (SSD) PreventionThe purpose of this study is to compare the effect of a brief family-based psychosocial intervention that addresses modifiable SSD risk factors on persistent and distressing psychotic-like experiences in children and young adults with a family history of SSD and high versus low baseline SSD-like brain patterns