Early life stress is associated with the default mode and fronto-limbic network connectivity among young adults

Miro Ilomäki; Jallu Lindblom; Viljami Salmela; Marjo Flykt; Mervi Vänskä; Juha Salmi; Tuija Tolonen; Kimmo Alho; Raija-Leena Punamäki; Patrik Wikman

doi:10.3389/fnbeh.2022.958580

Early life stress is associated with the default mode and fronto-limbic network connectivity among young adults

Front Behav Neurosci. 2022 Sep 23:16:958580. doi: 10.3389/fnbeh.2022.958580. eCollection 2022.

Authors

Miro Ilomäki¹, Jallu Lindblom^{2

3}, Viljami Salmela¹, Marjo Flykt^{1

2}, Mervi Vänskä², Juha Salmi^{1

4}, Tuija Tolonen¹, Kimmo Alho^{1

5}, Raija-Leena Punamäki², Patrik Wikman¹

Affiliations

¹ Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
² Faculty of Social Sciences/Psychology, Tampere University, Tampere, Finland.
³ Department of Clinical Medicine, Faculty of Medicine, University of Turku, Turku, Finland.
⁴ Department of Neuroscience and Biomedical Engineering, Aalto University, Helsinki, Finland.
⁵ Advanced Magnetic Imaging Centre, Aalto NeuroImaging, Aalto University, Espoo, Finland.

Abstract

Exposure to early life stress (ELS) is associated with a variety of detrimental psychological and neurodevelopmental effects. Importantly, ELS has been associated with regional alterations and aberrant connectivity in the structure and functioning of brain regions involved in emotion processing and self-regulation, creating vulnerability to mental health problems. However, longitudinal research regarding the impact of ELS on functional connectivity between brain regions in the default mode network (DMN) and fronto-limbic network (FLN), both implicated in emotion-related processes, is relatively scarce. Neuroimaging research on ELS has mostly focused on single nodes or bi-nodal connectivity instead of functional networks. We examined how ELS is associated with connectivity patterns within the DMN and FLN during rest in early adulthood. The participants (n = 86; 47 females) in the current functional magnetic resonance imaging (fMRI) study were young adults (18-21 years old) whose families had participated in a longitudinal study since pregnancy. ELS was assessed both prospectively (parental reports of family relationship problems and mental health problems during pregnancy and infancy) and retrospectively (self-reported adverse childhood experiences). Inter-subject representational similarity analysis (IS-RSA) and multivariate distance matrix regression (MDMR) were used to analyze the association between ELS and the chosen networks. The IS-RSA results suggested that prospective ELS was associated with complex alterations within the DMN, and that retrospective ELS was associated with alterations in the FLN. MDMR results, in turn, suggested that that retrospective ELS was associated with DMN connectivity. Mean connectivity of the DMN was also associated with retrospective ELS. Analyses further showed that ELS-related alterations in the FLN were associated with increased connectivity between the prefrontal and limbic regions, and between different prefrontal regions. These results suggest that exposure to ELS in infancy might have long-lasting influences on functional brain connectivity that persist until early adulthood. Our results also speak for the importance of differentiating prospective and retrospective assessment methods to understand the specific neurodevelopmental effects of ELS.

Keywords: adverse childhood experience (ACE); default mode network (DMN); early life stress (ELS); fronto-limbic network; functional connectivity.