Within‐person dual‐pathway model linking optimism to depression: A random‐intercept cross‐lagged panel study of cognitive bias and loneliness among Chinese university students

Abstract

This 1‐year longitudinal study applied a random intercept cross‐lagged panel model (RI‐CLPM) to examine how optimism influences depression through negative cognitive bias and loneliness among Chinese college students, disentangling within‐person processes from stable between‐person differences. 886 college students completed the Beck Depression Inventory, Optimism Scale, Negative Cognitive Bias Questionnaire and UCLA Loneliness Scale at three time points over 1 year. (1) All four variables (optimism, negative cognitive bias, loneliness, depression) were significantly correlated across three time points (p < .001). (2) RI‐CLPM revealed: within‐person surges in optimism predicted lower negative cognitive bias ( β  = −.28, p  < .001) and loneliness ( β  = −.35, p  < .001) at the next wave; these reductions predicted lower depression ( β  = .36 and .41, p  < .001). Mediation was partial through negative cognitive bias (indirect β  = −0.11, 95% CI [−0.18, −0.05]) but complete through loneliness (indirect β  = −0.15, 95% CI [−0.23, −0.08]). Optimism at T1 negatively predicted negative cognitive bias and loneliness at T2, which positively predicted depression at T3. After accounting for between‐person variability, within‐person increases in optimism predicted subsequent decreases in depression through two concurrent pathways: negative cognitive bias and loneliness.