Yes, ADHD ay maaaring maging hereditary, if may ADHD ka or sa partner mo, mas mataas ang chance na mapasa sa baby, pero hindi guaranteed talaga! Usually makikita na ang signs around age 3-4 onwards, though sa mga preschool age pa lang it's hard to tell kasi normal lang din ang hyperactivity, pero if notice mo na consistently ang distraction, impulsivity, or hyperactivity compared sa peers niya, good idea to bring it up sa pediatrician para ma-assess properly. Isa sa mga mum friends ko, she noticed sa son niya around age 5 during school na hindi siya nakakafocus, then got evaluated and confirmed ADHD talaga, nag-intervene early at sobrang helpful! The important thing is hindi mo dapat mag-self-diagnose or worry too much early pa, observe lang and document the behaviors para clearer ang picture when you talk to the doctor.