The goal of this clinical trial is to implement and examine the clinical effectiveness in a randomized study of the Catalan and Spanish versions of the culturally adapted What Were We Thinking (WWWT) psychoeducational intervention in primary care services, with the aim of preventing and reducing the prevalence of postpartum mental illness in new mothers. Additionally, the trial will assess the acceptability and accessibility of the intervention by families and professionals. Researchers will compare Usual Care (standard postnatal care provided by professionals from the Sexual and Reproductive Health Service) with Intervention group (usual care plus two psychoeducative intervention WWWT sessions) to see if the WWWT intervention is better than Usual Care at preventing postpartum depression and anxiety disorders in new mothers. Participants will: * Take baseline questionnaires at 2-4 weeks postpartum * Take usual care or usual care plus two psychoeducative intervention WWWT sessions within the first 6 weeks postpartum * Take the same questionnaires used in baseline plus a semi-structured interview to diagnose major mental disorder (all participants) at 3 and 6 months follow-up * Take a brief anonymous self-report survey (only those participants taking the WWWT intervention)