Is it possible to have postpartum depression even when your child is over a year old?

Maybe: One can develop depression any time. If you were not depressed during the first few months after your baby is born, we wouldn't call it postpartum depression. If you were depressed during the postpartum period and it wasn't treated, you may still be depressed when the baby is a year old. Untreated postpartum depression often lasts over a year. Talk to your doctor!