Background: We aim to examine the effectiveness of Learning Through Play and Cognitive Behaviour Therapy (LTP+CaCBT), a culturally appropriate psychosocial intervention to address postnatal depression among Nigerian women and improve the well-being of their children. Women of reproductive age (ages 16 to 49) comprise about 60 million of Nigeria's 230 million people. About 30% of these mothers experience postnatal depression. The global health challenge our research addresses is that one in three women worldwide experience postnatal depression and suicidal thoughts after childbirth, with long-term negative consequences on their children and families. Since 30% of Nigerian mothers suffer from postnatal depression, they have significant risks of transferring intergenerational mental health problems to their children. Over 250 million children are at risk of lacking developmental support in low- or middle-income countries, including Nigeria, due to postnatal depression, and this limits the children from reaching their full potential in life. The treatment gap for postnatal depression in Nigeria is huge due to a shortage of mental health specialists. Culturally appropriate, nonspecialist-delivered interventions are very limited in Nigeria. Our proposal aims to address this gap in treating postnatal depression using non-specialists called Indigenous Community Health Workers (CHWs), who are more culturally knowledgeable, as the World Health Organisation recommended in their task-shifting strategy.

Methods: We will evaluate the treatment, costs and implementation outcomes of LTP+CaCBT with 432 depressed mothers. Eligible participants (mother-child pairs) will be randomly selected to receive LTP+CaCBT and Treatment As Usual (TAU) or TAU alone. Our LTP+CaCBT intervention is a manualised 12-session (90-minute each) of mother-child play activities delivered in-person by CHWs under the supervision of clinical psychologists/psychiatrists. The eligible mothers (aged 16-49 years who have children between ages 0-36 months) will be assessed for depression before the intervention and then again at 4 months and 6 months afterwards. We will conduct interviews and focus group discussions to understand participants' and CHWs' experiences of the intervention

Inclusion Criteria:

• 18 years and above
• A mother with a child (0-3 years)
• Able to provide full consent for their participation
• A resident of the trial catchment areas
• Able to complete a baseline assessment
• Score 5 or above on Patient Health Questionnaire (PHQ-9)
• available for follow-up at 4 and 6 months post-enrolment

Exclusion Criteria:

• Less than 18 years
• Medical disorder that would prevent participation in a clinical trial, such as Tuberculosis or heart failure
• Temporary residents are unlikely to be available for follow-up
• Active suicidal ideation or any other severe mental disorder
• Patients currently undergoing severe mental health treatment
• Non-residents of the trial environs
• Unable to consent
• Unable to speak and understand English language
• Other significant physical or learning disability

Female participants - mothers of children between the ages of 0 and 3 years suffering from postnatal depression as a result of childbirth and parenting.

Only IPD used in the results publication.