In the multivariable analysis, prior psychiatric illness (adjusted odds ratio (aOR) 2.99; 95% CI 0.84–10.66, p = 0.091), moderate depression (aOR 2.52; 95% CI 0.90–7.06, p = 0.079) and lower education level (tertiary education: aOR 0.47; 95%CI 0.20–1.17, p = 0.088) tended to be significantly associated with poor IHDS performance, while CD4+ T-lymphocyte level was no longer significant. This evidence concerns the gene CD4 and depressive disorder.