Schizophrenia and schizophrenia-spectrum personality disorders in the first-degree relatives of children with schizophrenia - The UCLA Family Study

Background: This study tested the hypothesis that childhood-onset schizophr enia (COS) is a variant of adult-onset schizophrenia (AOS) by determining i f first-degree relatives of COS probands have an increased risk for schizop hrenia and schizotypal and paranoid personality disorders. Methods: Relatives of COS probands (n=148) were compared with relatives of attention-deficit/ hyperactivity disorder (ADI-ID) (n=368) and community co ntrol (n=206) probands. Age-appropriate structured diagnostic interviews we re used to assign DSMIII-R diagnoses to probands and their relatives. Famil y psychiatric history was elicited from multiple informants. Diagnoses of r elatives were made blind to information about probands' diagnoses. Final co nsensus diagnoses, which integrated family history, direct interview inform ation, and medical records, are reported in this article. Results: There was an increased lifetime morbid risk for schizophrenia (4.9 5%+/-2.16%) and schizotypal personality disorder (4.20% +/- 12.06%) in the parents of COS probands compared with parents of ADHD (0.45%+/-0.45%, 0.91% +/-0.63%) and community control (0%) probands. The parents of COS probands diagnosed as having schizophrenia had an early age of first onset of schizo phrenia. Risk for avoidant personality disorder (9.41%+/-3.17%) was increas ed in the parents of COS probands compared with parents of community contro ls (1.67%+/-1.17%). Conclusions: The psychiatric disorders that do and do not aggregate in the parents of COS probands are remarkably similar to the disorders that do and do not aggregate in the parents of adults with schizophrenia in modern fam ily studies. These findings provide compelling support for the hypothesis o f etiological continuity between COS and AOS.