Does positive affect mediate the association of multimorbidity on depressive symptoms?

Objectives Multimorbidity poses various challenges, and previous research has indicated a causal relation with depression. As multimorbidity is not curable, the underlying mechanisms are of great interest. Positive affect is a major resource for coping with chronic conditions and for the prevention of depression. Long-term multimorbidity, however, may deplete positive affect. The purpose of this paper is to investigate the role of positive affect in the association between multimorbidity and depressive symptoms.Method We used four consecutive waves (2008, 2011, 2014, 2017) of the nationally representative German Ageing Survey (DEAS) with a total of 1,558 older adults aged 40 and over. To account for time-varying confounding, exposure-induced mediator-outcome confounding, and reciprocities, we applied the mediational g-formula with inverse-probability weighting techniques. We also tested for exposure-mediator interaction to adjust for differences in mediation across the duration of multimorbidity.Results We confirmed a positive longitudinal relation between multimorbidity and depressive symptoms, both of which were negatively associated with while positive affect. The model without interaction indicated a share mediated of ca. 18.3% on the total effect of multimorbidity on depressive symptoms. Addition of interaction led to substantial differences for multimorbidity duration and levels of positive affect. Associations for long-term multimorbidity (at least two survey waves) were more substantial, and the share mediated doubled (>40%). Additionally, the direct effect of multimorbidity on depressive symptoms diminished for short-term multimorbidity.Conclusion Strengthening positive affect could reduce depressive symptoms in those facing multimorbidity. This study also discusses methodological challenges in performing longitudinal mediation analysis. We advise researchers to consider the mediational g-formula and exposure-mediator interaction.

Parental education, television exposure, and children's early cognitive, language and behavioral development.

The association between television exposure and children's development is subject to controversial debates. Heavy television exposure may be detrimental to children by overstimulating their developing brains. It may also infringe on time that children would otherwise spend on more developmentally beneficial activities or parental interactions. In the present analysis, we use data from the 2004/5 birth cohort of the Growing Up in Scotland study to investigate relations between hours of weekly television measured around the ages of two to four and as average over this period with children's linguistic, cognitive, and behavioral outcomes around the age of five. Our analysis shows differences in the level and growth of television exposure by parental education. However, we did not find any substantive associations between television exposure and children's cognitive or language ability. We found small associations of television exposure with conduct problems and prosocial behavior, particularly for children of less-educated parents. Overall, the results suggest that the impact of television on children's development is less pronounced than often assumed.

Early Maternal Employment and Children's Vocabulary and Inductive Reasoning Ability: A Dynamic Approach.

This study investigates the relationship between early maternal employment history and children's vocabulary and inductive reasoning ability at age 5, drawing on longitudinal information on 2,200 children from the Growing Up in Scotland data. Prior research rarely addresses dynamics in maternal employment and the methodological ramifications of time-variant confounding. The present study proposes various measures to capture duration, timing, and stability of early maternal employment and uses inverse probability of treatment weighting to control for time-variant confounders that may partially mediate the effect of maternal employment on cognitive scores. The findings suggest only modest differences in the above ability measures between children who have been exposed to very different patterns of eary maternal employment, but with similar observed covariate history.