Psychological risk and protective factors of immunity: a cross-cultural network analysis

Evidence shows psychological factors (e.g. stress) are linked to immunity, yet there is a lack of research investigating the complex interactions between psychological factors and immune function. Network analysis is useful to investigate complex interrelations between relevant health-related variables. This study applied network analyses to examine associations between psychological protective factors (mindfulness, quality of life, positive affect, resilience) and risk factors (depression, anxiety, stress) and self-reported immune functioning in samples from New Zealand (n = 1039), India (n = 384), and Italy (n = 1061). In the overall and country-specific networks, anxiety was consistently associated with poor immunity. In New Zealand and India, but not Italy, health-related quality of life was positively associated with stronger immunity. Depression, anxiety and stress were strongly interlinked in all samples. Depression was also linked to poor quality of life and poor resilience, and anxiety to mindfulness. These findings suggest that anxiety is uniquely linked to immune function across cultures and highlights the potential to address anxiety to improve immunity. The positive quality of life-immunity association in New Zealand and India, but not Italy, suggests cultural differences may play a role, warranting consideration in future research, with a view to inform culturally appropriate interventions. Overall, psychological factors demonstrate consistent connections with immune function cross-culturally. Cultural nuances in the quality of life-immunity link deserve further investigation to inform localized immune function interventions.