CD4 and depressive disorder: Comorbid psychiatric illnesses, including depression, are common in HIV-infected patients.[34] The prevalence of depression in HIV-infected clinic populations has ranged from 22% to 38%.[34, 35] Younger age, unemployment, lack of health insurance, low CD4+ cell counts, HIV-related symptoms, not having a partner, poor quality of social support, and use of noninjection drugs were significant predictors of depression in one study.[36] Patients with HIV infection who are older than 35 years are more likely to suffer from depression, anxiety, confusion, and fatigue.