A systematic review of conceptualizations and statistical methods in longitudinal studies of resilience

Resilience research seeks to understand how protective factors interact with adversity to yield positive outcomes over time. However, inconsistent conceptualizations and diverse methodologies limit comparability across studies. In this systematic review (preregistered on PROSPERO CRD42019138732 ), we examined 193 longitudinal psychosocial resilience studies published over the past 30 years, including 805,660 participants across all age groups. We analyzed (1) conceptualizations of resilience as a trait, outcome or process; (2) statistical approaches (variable-centered, person-centered or combined); (3) types of models and their relationship to adversity (for example, protective, promotive, vulnerability, differential susceptibility); and (4) heterogeneity in adversity, outcomes and promotive or protective factors. Most studies lacked an explicit resilience definition, and only 32% explicitly defined it as a trait (6%), an outcome (19%) or a process (8%). Variable-centered approaches predominated (85%), with most studies testing moderation and identifying protective/promotive effects, while few supported differential susceptibilities. Adversities were primarily childhood- or family-based, with mental health outcomes most common. Protective factors spanned individual, family and community levels, while neurobiological factors were rarely considered. We offer recommendations from our review to improve clarity and consistency in conceptualizing, operationalizing and interpreting resilience in longitudinal research. This research systematically reviewed 193 longitudinal studies on psychosocial resilience, revealing inconsistent definitions, predominant variable-centered methodologies and a focus on childhood adversities, while highlighting the need for clearer conceptual frameworks and improved operationalization in future investigations.