Categorical and dimensional Psychopathology in dutch and us bipolar offspring: A preliminary cross-national comparison

Background Cross-national differences in the prevalence of bipolar disorder and other psychopathology in offspring of parents with bipolar disorder have been reported. The present study aims to explore and clarify cross-national differences in categorical and dimensional psychopathology between US and Dutch bipolar offspring. Methods We compared two existing bipolar offspring studies (age range 10-18 years): the US Pittsburgh BIOS study (n=224, data collection 2001-2007) and the Dutch Bipolar Offspring Study (n=136, data collection 1997-1999 and 2010-2012). Categorical psychopathology was ascertained through the Schedule for Affective Disorders and Schizophrenia for School Age Children and dimensional psychopathology through the Child Behavior Checklist completed by parents. results Categorical psychopathology, particularly anxiety and behavioral disorders, was more common in the US sample (66% vs 44%, p < .001). There were no cross-national differences in prevalence of mood disorders, including bipolar I or II disorder. After controlling for demographic and parental characteristics, the effect of geographic origin diminished, but remained significant for “any psychopathology” and “mood disorders with comorbid conditions”. There were no significant cross-national differences in dimensional psychopathology. Limitations The present study should be considered preliminary as a measure of inter-site reliability was not available. Conclusions US and Dutch bipolar offspring share a similar liability for mood disorders. In categorical psychopathology, cross-national differences were observed, but these were partially explained by differences in sample characteristics. Differences on the categorical level were not confirmed in dimensional psychopathology. Potential explanations for the observed differences and suggestions for future research are discussed.