Masaru Horikoshi

Background Depression is a leading cause of global disability, and subthreshold cases contribute substantially to the burden. Cognitive behavioural therapy (CBT) is effective for depressive symptoms, but its impact on social functioning in subthreshold depression remains unclear. Objective This study evaluated the effects of smartphone-based CBT on social functioning and personal health records among individuals with subthreshold depression and examined whether a personalised and optimised therapy (POT) algorithm enhanced these outcomes. Methods We performed a secondary analysis of the RESiLIENT trial (n=5361). Participants were stratified by baseline Patient Health Questionnaire-9 (PHQ-9) scores (0–4 and 5–14) and randomised to nine CBT app groups or a self-check group. Outcomes included social functioning and health records. A mixed-effects model for repeated measures was used to analyse the outcomes. The POT algorithm selected CBT skills tailored to individual characteristics. Findings Depressive symptoms improved in both PHQ-9 groups compared with those of the self-check group, but gains in social functioning were modest, observed mainly in the PHQ-9 score ≤4 group. No consistent benefits were seen for health behaviours, job resignation, sick leave or healthcare costs. However, in a simulated randomised comparison using 10-fold cross-validated datasets, the POT algorithm had potentially beneficial effects for productivity (standardised mean difference (SMD)=0.16, 95% CI 0.03 to 0.29) and social adjustment (SMD=−0.13, 95% CI −0.26 to 0.00). Conclusions Smartphone CBT effectively reduced depressive symptoms but showed limited impact on social functioning and healthcare costs. Personalised optimisation may modestly improve productivity and adjustment, suggesting its promise for enhancing social outcomes. Clinical implications Personalised tailoring of CBT skills may strengthen the effects of digital interventions on social functioning. Trial registration number UMIN000047124.

BACKGROUND: Depression is a leading cause of global disability, and subthreshold cases contribute substantially to the burden. Cognitive behavioural therapy (CBT) is effective for depressive symptoms, but its impact on social functioning in subthreshold depression remains unclear. OBJECTIVE: This study evaluated the effects of smartphone-based CBT on social functioning and personal health records among individuals with subthreshold depression and examined whether a personalised and optimised therapy (POT) algorithm enhanced these outcomes. METHODS: We performed a secondary analysis of the RESiLIENT trial (n=5361). Participants were stratified by baseline Patient Health Questionnaire-9 (PHQ-9) scores (0-4 and 5-14) and randomised to nine CBT app groups or a self-check group. Outcomes included social functioning and health records. A mixed-effects model for repeated measures was used to analyse the outcomes. The POT algorithm selected CBT skills tailored to individual characteristics. FINDINGS: Depressive symptoms improved in both PHQ-9 groups compared with those of the self-check group, but gains in social functioning were modest, observed mainly in the PHQ-9 score ≤4 group. No consistent benefits were seen for health behaviours, job resignation, sick leave or healthcare costs. However, in a simulated randomised comparison using 10-fold cross-validated datasets, the POT algorithm had potentially beneficial effects for productivity (standardised mean difference (SMD)=0.16, 95% CI 0.03 to 0.29) and social adjustment (SMD=-0.13, 95% CI -0.26 to 0.00). CONCLUSIONS: Smartphone CBT effectively reduced depressive symptoms but showed limited impact on social functioning and healthcare costs. Personalised optimisation may modestly improve productivity and adjustment, suggesting its promise for enhancing social outcomes. CLINICAL IMPLICATIONS: Personalised tailoring of CBT skills may strengthen the effects of digital interventions on social functioning. TRIAL REGISTRATION NUMBER: UMIN000047124.

BACKGROUND: Marital satisfaction is a key determinant of maternal mental health during the perinatal period. Identifying psychosocial factors associated with changes in marital satisfaction can help inform early preventive interventions. METHODS: This longitudinal study examined associations between psychosocial factors measured during pregnancy and changes in marital satisfaction from pregnancy to 52 weeks postpartum. Participants were 752 pregnant women in Japan (mean age = 32.0 ± 4.3 years) who completed online surveys during pregnancy and at 52 weeks postpartum. Marital satisfaction was assessed using the Quality of Marriage Index (QMI), a validated measure of relationship satisfaction, and categorized into three groups based on QMI score differences: improved (≥ 1-point increase), unchanged (0-point difference), and worsened (≥ 1-point decrease). Psychosocial variables included depressive symptoms assessed by the Edinburgh Postnatal Depression Scale (EPDS), household income, perceived burden of household chores and childcare, parity, and perceived family support. Multinomial logistic regression was used to examine associations between these variables and changes in marital satisfaction. RESULTS: Higher levels of depressive symptoms during pregnancy, as measured by the EPDS, were significantly associated with worsening marital satisfaction after childbirth (RRR = 2.38, 95% CI: 1.30-4.37, p = 0.005). Lower household income also predicted a decline in satisfaction (RRR = 0.999, 95% CI: 0.999-1.00, p = 0.017). Participants who reported extremely long hours of household chores and childcare were less likely to experience improved satisfaction (RRR = 0.15, 95% CI: 0.04-0.65, p = 0.011). First-time childbirth was negatively associated with improvement (RRR = 0.41, 95% CI: 0.20-0.87, p = 0.019). Higher levels of perceived family support were also associated with less improvement in marital satisfaction (RRR = 0.89, 95% CI: 0.80-0.98, p = 0.017). CONCLUSION: Psychosocial factors during pregnancy, including depressive symptoms, economic hardship, and perceived domestic burden, were significantly associated with subsequent changes in marital satisfaction. These findings underscore the importance of early mental health screening and supportive interventions for expectant couples.