2.1.2 Family History
The main inclusion criterion for this study’s at-risk group was for
participants to have at least one first-degree relative with BD.
Familial history was identified using the “ABCD Parent Family History
Summary Scores” data. It includes a summary score of all that was
reported by the caregiver on lifetime occurrences of different
psychological issues in first- and second-degree biological relatives of
the participants. Variables of interest were those that assessed whether
“mania problems” were experienced by the father, mother, or siblings.
In total, 625 participants were considered at-risk at baseline, and 545
were identified at the two-year follow-up. Adopted children were not
uniformly excluded from the current study since these assessments
specifically referred to biological first-degree relatives.