Mediating effects of physical activity, BMI, and dietary iron intake on the relationship between depression and chronic headaches

Depression is a significant psychiatric condition linked to chronic headache outcomes, necessitating an exploration of the mechanisms involved in this relationship. This study aimed to examine whether physical activity, body mass index (BMI), and dietary iron intake mediate the relationship between depression and chronic headaches using path analysis. This study employed a cross-sectional approach. A total of 9,918 participants aged 35-65 years were selected through convenience sampling from the baseline phase of the Ravansar Non-Communicable Disease (RaNCD) Cohort Study, part of the larger PERSIAN cohort. Data collection included sociodemographic and clinical information, alongside standardized self-report instruments for assessing physical activity and dietary intake (Food Frequency Questionnaire). The statistical analyses were performed using SPSS version 22 and MPLUS version 8.3. Path analysis was used to assess the direct, indirect, and total effects of depression on chronic headaches. The results demonstrated a significant direct effect of depression on chronic headaches (β = 0.07, 95% CI: 0.05 to 0.08). Additionally, significant indirect effects were observed through the mediating variables of BMI (β = 0.001, 95% CI: 0.000 to 0.002) and dietary iron intake (β = 0.002, 95% CI: 0.001 to 0.002). In contrast, the indirect pathway through physical activity was not statistically significant (β = 0.000, 95% CI: -0.001 to 0.000). Increased BMI and reduced dietary iron intake, influenced by depression, were associated with a higher prevalence of chronic headaches. These findings suggest that interventions targeting chronic headaches should not only address depressive symptoms but also incorporate strategies for weight management and improving dietary iron intake. A comprehensive approach that integrates both psychological and physiological components may enhance treatment outcomes. Future studies employing longitudinal designs are warranted to further elucidate these relationships and inform more effective intervention strategies.