Postpartum depression (PPD) may impair the mother-infant relationship and lead to both short and long-term suboptimal development of the baby. This study aims to evaluate the effectiveness of a targeted intervention (HUGS: Happiness Understanding Giving and Sharing) for enhancing the mother-infant relationship.

Post-partum depression (PPD) is the most common psychological pathology following childbirth and affects 12% of women in France. This pathology may impair the mother-infant relationship and lead to suboptimal development of the baby in the short and long-term. The prevalence of early interaction disorders is estimated at 73% among women suffering from PPD. Although treatments for PDD are effective, the mother-infant interaction remains impaired, as well as the short, medium and long-term development of the child. It is therefore essential to develop at a very early stage an intervention specifically targeting the mother-infant interaction, and to integrate this care into the general care given to mothers suffering from PPD.

A short cognitive-behavioural therapy intervention focused on improving the quality of the mother-infant relationship (the HUGS program: Happiness, Understanding, Giving and Sharing) has been created and validated by Prof. Jeannette Milgrom's Australian team. The objective of our study is to evaluate the effectiveness of the HUGS programme compared to a Playtime control group using a randomised controlled trial in a population of women suffering from PPD and being cared for in 7 French maternity hospitals. The comparison will be made 6 months after intervention initiation using "Factor 1: Mother Positive Affective Involvement and Verbalization" of the PCERA (Parent-Child Early Relational Assessment) mother-child interaction evaluation scale.

Inclusion criteria regarding the mother:

• Person affiliated or beneficiary of a social security plan;
• Free, informed and written consent signed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research);
• Woman who gave birth in one of the maternity hospitals participating in the study;
• Diagnosis of postpartum depression made by the perinatal psychiatry team according to the clinical criteria of the DSM-5;
• Time to onset of depressive symptoms within the first 12 months after childbirth;
• Treatment for postpartum depression that started at least 8 weeks ago with improved mood as assessed by the psychiatrist.

Inclusion criteria for the baby:

• Baby aged less than 1 year at inclusion;
• Twins will be able to participate in the study and benefit from the interventions;

Non-inclusion criteria concerning the mother:

• Uncontrolled substance use disorder;
• Presence of suicidal ideas at inclusion;
• Manic episode of a bipolar disease
• Psychiatric pathology decompensated upon inclusion and corresponding to the following list: Schizophrenic disorder, Schizoaffective disorder, Mood disorders with psychotic symptoms;
• Non French speaker.

Non-inclusion criteria for the baby:

- Baby hospitalized or having sustained medical care upon inclusion in the context of a somatic pathology.

Mothers

group attribution blinded to evaluators for the evaluation of the primary endpoint via video tapes