Development and Validation of the Choongo Postpartum Psychosis Scale-8 for Pre- and Postnatal Screening of Mothers at Primary Healthcare Level in Zambia

Background: Postpartum psychosis (PPP) is a severe but under-recognized maternal mental health condition, particularly in low- and middle-income countries where culturally adapted screening tools are scarce. In Zambia, PPP remains undocumented despite high rates of postnatal depression, and psychotic-like symptoms underscoring the need for context-specific instruments. This study sought to develop and validate the Choongo Postpartum Psychosis Screening Scale (CPPS-8), an 8-item tool tailored for use in Mother and Child Health (MCH) units in Lusaka, Zambia. 
Methods: A cross-sectional quantitative design was employed. Tool development followed iterative refinement from 36 to 8-items, guided by expert panel review, pilot testing, and psychometric evaluation. Eighty-eight postnatal mothers within six weeks of childbirth were randomly sampled from first-level hospitals. Reliability was assessed using Cronbach’s alpha, test–retest and inter-rater measures. Diagnostic accuracy was evaluated against DSM-5 and ICD-11 psychiatric assessments. 
Results: The final 8-item CPPS demonstrated acceptable internal consistency (α = 0.82), strong test–retest reliability (r = 0.79), and high inter-rater agreement (r = 0.83). Sensitivity (84.1%) and specificity (88.6%) confirmed robust diagnostic accuracy. Sleep disturbance (59.1%) and child care neglect (53.4%) emerged as the strongest predictors of positive screens. Overall, 12.5% of mothers screened positive, with 10.2% confirmed by psychiatric experts. 
Conclusion: The CPPS is a brief, reliable, and culturally relevant screening tool for early detection of PPP in resource-constrained maternal health settings. Its integration into routine antenatal and postnatal care can strengthen early intervention, safeguard maternal-infant wellbeing, and inform national mental health policy.