Perinatal depression poses substantial risks to both mothers and their offspring. Given its chronic and recurrent nature, developing effective prevention strategies is crucial. Internet-based cognitive–behavioural therapy (iCBT) has shown promise. However, the efficacy of specific CBT skills and the influence of individual differences remain unclear.

This protocol describes two harmonised multicentre, open-label, six-arm randomised controlled trials. Across both trials, a total of 2400 pregnant women between 10 and 20 weeks of gestation will be enrolled. After completing psychoeducation (PE), participants will be randomised to either the control condition (PE only) or one of five CBT programmes: behavioural activation (BA), assertion training, BA+cognitive restructuring, BA + problem solving or BA + behaviour therapy for insomnia. The objectives of the study are: (1) to ascertain that the iCBT approach is effective in perinatal depression, (2) to identify active CBT skills for perinatal women and (3) to examine interactions between these CBT skills and individuals’ baseline characteristics to find personalised and optimised therapy for individual women. The primary outcome is the point prevalence of depression at 1 month postpartum, defined as scoring of 9 or higher on the Edinburgh Postnatal Depression Scale.

The study has been approved by the Kyoto University Graduate School of Medicine Ethics Committee (C1710) and Nagoya City University Certified Review Board (2024A007). Anonymised study results will be presented at conferences and published by the investigators in peer-reviewed journals.

jRCTs042240162 (hospital-based, on-site trial) and jRCT1050250074 (nationwide online trial).

To examine the association between individual social capital and depression in older adults in Iran and to test the hypothesis that higher levels of social capital are inversely associated with depressive symptoms.

Cross-sectional study using baseline data from a longitudinal cohort.

Community-based study conducted in primary care settings across urban and rural areas of Birjand County, Eastern Iran.

A total of 1348 community-dwelling individuals aged 60 years and older were recruited through multistage stratified cluster random sampling. Participants who were bedridden or had end-stage disease (life expectancy

The primary outcome was depression status, measured using the Patient Health Questionnaire 9 items, with a score≥10 indicating depression. The main explanatory variable was social capital, assessed using a validated 69-item questionnaire capturing domains such as collective activity, social trust and network structure. Univariable and multivariable logistic regression analyses were conducted to estimate adjusted ORs and 95% CIs for associations between depression and social capital dimensions. Statistical analyses were performed using Stata V.12.0

Of the total participants, 268 (19.94%) were identified as having depressive symptoms, with a significantly higher prevalence among women (27.44%) compared with men (11.88%). Depression was more prevalent among those in the lowest wealth quintile (32.09%) and individuals with low literacy levels (28.10%). Participation in collective activities was inversely associated with depression in the second (OR=0.62, 95% CI (0.42 to 0.93)), third (OR=0.45, 95% CI (0.29 to 0.71)), fourth (OR=0.59, 95% CI (0.37 to 0.93)) and fifth (OR=0.37, 95% CI (0.22 to 0.61)) quintiles. Social trust was also associated with lower odds of depression in the third (OR=0.62, 95% CI (0.39 to 0.99)) and fourth (OR=0.64, 95% CI (0.42 to 0.97)) quintiles. Furthermore, the second (OR=0.63, 95% CI (0.40 to 0.99)) and fifth (OR=0.38, 95% CI (0.23 to 0.63)) quintiles of social network structure were inversely related to depression. These findings suggest that higher levels of social capital, particularly in terms of collective participation, trust and social networks, are associated with a reduced likelihood of depressive symptoms in older adults.

Higher levels of social capital, particularly collective engagement, interpersonal trust and diverse social networks, are associated with lower odds of depression in older adults. These findings support the need for community-based interventions to strengthen social capital as a strategy for mental health promotion among the elderly in low-income and middle-income settings.