Castro Filho, Bernardo Galvão “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”.Brazilian National Research Council (Conselho Nacional de Desenvolvimento Científico e Tecnológico: CNPq) and Bahia State Research SupportFoundation (Fundação de Amparo à Pesquisa do Estado da Bahia:FAPESB).To investigate the role of demographic variables in the relationship between the presence of HAM/TSP and current major depression. Methods: It is a cross-sectional study of 108 HTLV-1 infected patients (47 with TSP/HAM)resident of Salvador, Brazil. The Mini International Neuropsychiatric Interview, BrazilianVersion 5 was used to evaluate the presence of depression. Prevalence ratios were used todescribe relationship between HAM/TSP and depression. The HAM/TSP classification wascarried out according to the criteria proposed by Castro-Costa et al.Results: Prevalence of depression was 37.96%. No association was observed between pres-ence of HAM/TSP and diagnosis of current major depression in the global analysis of patients(PR: 0.94; CI 95%: 0.57–1.55). In the stratified analysis, however, greater prevalence of depres-sion was observed amongst individuals with HAM/TSP in the 18–39 age group (PR: 2.59; CI95%: 1.36–4.95).Conclusion: Our findings suggest that age is an effect modifier in the relationship betweenHAM/TSP and depression, and this aspect should be considered in future studies on thetopic.