Investigating causal associations between feeling loved in childhood and anxiety and depression

: A PPI-informed project

Abstract

Anxiety and depression are the most common mental health disorders and are associated with significant disease burden. Children of parents with anxiety and depression are at an increased risk of experiencing these disorders themselves. This risk can be transmitted via genetic or environmental pathways. In this project, I aimed to further investigate causal associations in the intergenerational transmission of depression and anxiety, informed by patient and public involvement (PPI).
I explored the beliefs of individuals with lived experience of depression and anxiety about the causes of these disorders and their research interests in this area. Using thematic analysis, I identified five key themes: trauma, personality characteristics, feeling loved in childhood, and family dynamics. Based on these findings, I focused on potential causal associations between feeling loved in childhood and depression and anxiety using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK Biobank cohort studies.
I found that feeling loved in childhood mediated the intergenerational transmission of maternal, but not paternal, anxiety and depression. Additionally, this mediation effect was independent of offspring infant attachment security and maternal enjoyment of the child. In a genome-wide association study, I found no evidence that common additive genetic variants were associated with feeling loved in childhood or that feeling loved in childhood was genetically correlated with anxiety or depression. Finally, using Mendelian randomisation, I found no evidence that anxiety or depression are causally associated with feeling loved in childhood.
These findings provide tentative support for interventions aimed at increasing one’s perception of feeling loved in childhood in order to prevent the intergenerational transmission of maternal and anxiety and depression. However, there are a number of important limitations which constrain the potential applications of the findings.

Date of Award	4 Feb 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Hannah M Sallis (Supervisor), Marcus R Munafo (Supervisor), Rebecca Pearson (Supervisor) & Jorien L Treur (Supervisor)