True clinical regulatory problems require medical intervention. This distinction matters, and it comes down to three metrics: intensity, persistence, and systemic disruption to the family. OK, unpack that. According to the DC .05 diagnostic classification, which is the global standard for infant mental health, a baby isn't diagnosed with an RP just because they had a bad week of teething or a sleep regression. So it has to be ongoing, and RP is diagnosed when the functioning of the infant, or the entire family unit, is persistently impaired over a long period. So it's not just that the baby cries a lot; it's that the baby cries for hours, cannot be soothed by any known method, refuses to sleep for more than 40 minutes at a time for months on end, and the parents are suffering acute psychological distress because the family system has just collaps ...