Differences in mental health between younger and older adults in complex humanitarian settings in low-income and middle-income countries: retrospective analysis from Médecins Sans Frontières-supported mental health services, 2019–2024

Background Humanitarian emergencies increase the risk of development or exacerbation of mental health conditions. This study documents how mental health differs between younger and older adults to inform adapted mental health services in humanitarian settings.Methods This multicountry study includes adults who accessed Médecins Sans Frontières-supported mental health services in humanitarian settings across 20 low-income and middle-income countries between July 2019 and July 2024. Mental health symptoms and precipitating events were compared between younger (20–49 years old) and older adults (50 years or older) adjusting for sex and displacement status using logistic regression analyses.Findings Data of 177 228 adults were included. Adults most frequently presented at mental health services with anxiety-related (44%; 70 496/158 665) and mood-related symptoms (26%; 41 732/158 665). Older adults had higher odds of reporting symptoms related to ageing (adjusted Odds Ratio (aOR)=4.44; 95% CI 3.84 to 5.14), physical complaints (aOR=2.74; 95% CI 2.65 to 2.83), social functioning (aOR=1.12; 95% CI 1.03 to 1.23) and neuro-psychiatry (aOR=1.09; 95% CI 1.02 to 1.17), and lower odds of reporting symptoms related to anxiety (aOR=0.68; 95% CI 0.66 to 0.70), mood (aOR=0.64; 95% CI 0.62 to 0.67) and behaviour (aOR=0.57; 95% CI 0.52 to 0.61), with variation by sex and displacement status. Compared with younger women, older women had higher odds of reporting violence, socioeconomic functioning and displacement, with variation by displacement status. Compared with younger men, older men had higher odds of reporting medical illness.Interpretation Significant differences in mental health symptoms were identified between younger and older adults, with variations by sex and displacement status. Older adults were more likely than younger adults to present symptoms related to ageing. Compared with their younger counterparts, older women were more likely to report experiences of violence, and older men were more likely to report medical illness. These findings underscore the need for age-sensitive and sex-sensitive mental health services in humanitarian settings, including staff training on age-related mental health presentations.