Parent data were split into lower and higher BAP groups.
Because of a positive skew, ADHD parent data were transformed using the natural log +1.
While only parent data were included in this analysis, age-eligible child participants also provided assent (participants < 18 years) or consent (participants ≥ 18 years) for his or her participation.
Mothers provided self-reports using Hazan and Shaver's (1987) Adult Attachment Style measure, the Brief Symptom Inventory, and the Parent Stress Inventory; observations of parenting data were made from 10-minute free play interactions.
For five parents data were found to be incomplete and were not further used in the analyses.
In over 11 000 adult twins, siblings and parents, data were collected at five time points in approximately 11 years.
In a structured telephone interview with the parents, data were collected on demographic information, the mother's medical conditions in pregnancy, her reproductive history, and other exposures.
On the negative side, parent report data are subject to recall bias and are necessarily inferior to school attendance and healthcare claims records for the outcomes of interest.
Only parenting group data are presented in this manuscript.
As 0 2.5 h parent fraction data were extrapolated to 4.5 h p.i., it is possible that parent fraction estimates at 4.5 h p.i. were overestimated.
As parent fraction data was limited to the first 2 h p.i., the accuracy of parent fraction estimates extrapolated to 4 h p.i. might be reduced.
