There are several explanations for the higher prevalence of depression among the adolescent with HIV when compared with the reported prevalence in the general population: one of the possible reason for this variation could be a significant effect of HIV infection on immunity (reduction in CD4 count) which subsequently increase risk of depression in those adolescents with the problem (those who have reduced CDA count), as suggested in previous studies [22, 38]. This evidence concerns the gene CD4 and major depressive disorder.