It’s already in the DSM.
Childress has this
Over 172 family law academics, domestic violence experts and children’s rights organisations around the world have written to the World Health Organisation (WHO) raising concerns about the health body’s decision to consider classifying parental alienation as a “Caregiver-child relationship problem”. The classification is being considered as an entry to the WHO’s official guide on diseases.…
— Read on researchingreform.net/2019/04/30/global-health-agency-told-not-to-add-parental-alienation-classification-by-lawyers-and-experts/