Table 1 Inclusion and exclusion criteria

Primary caregivers of infants and toddlers up to 3 years and 11 months.

Studies including specific groups of caregivers with intellectual disabilities and with current mental health problems such as schizophrenia, substance misuse and abuse, and children born preterm, at low birth weight or with congenital diseases.

Structured psychosocial parenting intervention delivered either antenatal or within the child’s first 3 years and 11 months of life.

Interventions not focusing specifically on parenting, interventions delivered at preconception or unstructured interventions.

Child and/or adolescent internalising problems up to age 18 and 11 months.

Studies reporting only externalising problems or cognitive or health related outcomes.

Randomised controlled trials (RCT) or quasi-RCTs either with individual or group levels of randomization. Cross-over trials.

Study designs such as quasi experimental studies (e.g., pre-post test), case control, cohort, cross-sectional and systematic reviews

No restrictions will be imposed.