Investigating time perspective as transdiagnostic processes across mental disorders

Abstract

Time perspective, encompassing past, present, and future dimensions, serves to imbue life experiences with order, coherence, and meaning. Abundant evidence suggests its association with a wide spectrum of mental illnesses. Notably, intervention strategies incorporating future time perspective (FTP) have gained significant traction in mental health. FTP, as a dimension of time perspective, represents the general mental capacity to anticipate the future, facilitating self-regulation, such as goal-seeking behaviours. Despite the recognition of time perspective as a likely transdiagnostic process, a comprehensive synthesis of its association with various mental disorders remains lacking. Furthermore, the promotive role of FTP necessitates an integrated model to elucidate its associations with a range of symptoms simultaneously, as well as rigorous examination at an intra-individual level to evaluate its effectiveness as an intervention strategy. To address these gaps, this thesis comprises four empirical studies. Chapter 2 presents a comprehensive systematic review and meta-analysis, exploring the transdiagnostic associations between different dimensions of time perspective and mental health problems. Multi-level random effect meta-analyses, utilising robust variance estimation methods for dimensions with sufficient effect sizes (df ≥ 4), suggest that various dimensions of time perspective are associated with different mental health problems. Specifically, internalising problems are linked to the future, present fatalistic, past positive, and past negative dimensions, and the synthesised index DBTP; addiction is associated with the future, present hedonistic, present fatalistic, and past negative dimensions; and neuroticism is related to the present fatalistic, past positive, and past negative dimensions. Additionally, the past negative dimension is associated with post-traumatic stress disorder (PTSD) and externalising problems, while the future and present hedonistic dimensions are linked to impulsivity. Importantly, these associations persist even after removing outliers. Chapter 3 employs a bifactor modelling approach, coupled with a cross-informant methodology, to investigate whether future orientation constitutes a transdiagnostic process. The findings suggest a transdiagnostic promotive role of future orientation in mental health and neurodevelopmental outcomes, particularly in the shared variance across conduct problems, ADHD symptoms, emotional difficulties, and peer problems during adolescence. In Chapter 4, a detailed examination of the specific components of the future time perspective is conducted. This analysis identifies future self-valence and self-connectedness as transdiagnostic factors negatively correlated with a spectrum of mental health problems (i.e., internalising, ADHD, psychosis-like symptoms, and substance use). Lastly, Chapter 5 examines the longitudinal association between occupational future time perspective and psychological/neurodevelopmental outcomes (i.e., internalising, externalising, and ADHD symptoms) using Random Intercept Cross-Lagged Panel Modelling (RI-CLPM). While the analysis uncovers some effects, unlike previous cross-sectional analyses, robust cross-lagged associations were not found when examining within-person longitudinal effects, prompting further investigation to better illuminate the nature of these associations. Collectively, these studies offer new insights into the interplay between time perspective and mental health, shedding light on its potential as a more targeted intervention strategy.