Depression as A Predictor of Suicidal Ideation: The Moderating Role of Social Support among Public Polytechnics Employees in South Western, Nigeria

Abstract

This study investigates whether depressive symptoms predict suicidal ideation among employees in public polytechnics in Southwestern Nigeria and examines social support as a moderator of this relationship. A cross-sectional survey was conducted among squandered (n = 450) employees across five polytechnics, selected via stratified random sampling. Depression was measured with the Beck Depression Inventory-II (BDI-II), suicidal ideation with the Columbia-Suicide Severity Rating Scale ((BDI-II), and perceived social support with the Multidimensional Scale of Perceived Social Support (MSPSS). Descriptive statistics indicated a mean PHQ-9 score of 9.6 (SD = 5.2), with 38.1% of participants showing moderate-to-severe depressive symptoms (PHQ-9 ≥ 10). Suicidal ideation was reported by 12.4% of respondents within the past month. A hierarchical multiple regression controlling for age, gender, marital status, and tenure revealed that depressive symptoms significantly predicted suicidal ideation (β = 0.42, p < 0.001), explaining 26% of the variance in ideation after covariates. Social support demonstrated a significant interaction with depression (ΔR² = 0.04, p = 0.02), indicating a buffering effect: high perceived social support attenuated the depression–ideation link (simple slopes: high support β = 0.28, p = 0.01; low support β = 0.55, p < 0.001). Subgroup analyses suggested stronger moderation among female employees and those in non-academic roles. Findings underscore the protective role of social support in reducing suicidal ideation among depressed workers and highlight the need for workplace interventions that strengthen social networks within public polytechnics.