Peer-reviewed article

Early childhood development and its impact on mental health in later life

Pieter van den Berg · 1 Mar 2026

Abstract

The challenge of connecting what happens in the first five years of life to mental health outcomes decades later has occupied developmental researchers for generations, yet translating that accumulated knowledge into actionable clinical prevention strategies remains an elusive goal for healthcare systems worldwide and in Belgium specifically. This research investigated the longitudinal relationship between early childhood developmental experiences and adult mental health symptomatology among a retrospective cohort of 189 Belgian adults assessed at two academic medical centers in the Flemish region. Participants aged 25 to 55 years completed comprehensive assessments spanning adverse childhood experience inventories, parental bonding evaluations, developmental milestone histories, and current psychiatric symptom measures using the General Health Questionnaire-28 and Connor-Davidson Resilience Scale at KU Leuven and Ghent University Hospital between November 2023 and September 2024. Our analysis revealed a strong positive correlation between adverse childhood experience scores and adult mental health symptom burden, with a Pearson coefficient of 0.67 indicating that nearly 45% of the variance in adult psychiatric symptomatology could be statistically traced to childhood adversity exposure levels. Scatter plot visualization confirmed this association across three distinct risk strata identified through cluster analysis: resilient individuals maintaining low symptom scores despite moderate adversity exposure, moderate risk individuals showing proportional symptom elevation tracking linearly with adversity, and high-risk individuals demonstrating severe symptom burden associated with elevated adversity histories and compounding vulnerability factors. Cognitive development emerged as the most frequently affected developmental domain at 28.6% of identified cases, followed by emotional regulation difficulties at 23.8% and social attachment disruptions at 19.6%, as illustrated by pie chart analysis of domain-specific developmental concern patterns across the full sample. Parental bonding quality demonstrated a significant protective association with adult resilience capacity, yielding a correlation coefficient of 0.58 that held across both male and female participants though with somewhat different effect magnitudes between genders that merit further investigation. The developmental pathway model constructed from these data traces how protective factors including secure attachment, cognitive stimulation, and healthy peer relationships interact with risk factors such as adverse childhood experiences, learning difficulties, and identity disruption across four developmental stages from early childhood through established adulthood. Participants who reported both high adversity and low parental bonding scored 23.4 points higher on the GHQ-28 than those with low adversity and high bonding, representing a clinically meaningful difference that substantially exceeds established thresholds for psychiatric caseness identification on this instrument. Resilience scores were 18.7 points higher among participants who received early supportive interventions during childhood compared to those who did not access such services, even after statistical controlling for baseline adversity levels and socioeconomic confounders. These findings carry balanced implications for both clinical practice and public health policy development. While early childhood experiences clearly shape adult mental health trajectories in measurable and consistent ways, the data also demonstrate that protective factors including strong parental bonding can substantially buffer adversity effects, suggesting that intervention at multiple developmental windows remains viable and potentially effective rather than limiting preventive efforts exclusively to the earliest years of life when adversity first occurs.