Relation of stressors and depressive symptoms to clinical progression of viral illness

OBJECTIVE: The aim of this research was to determine whether and in whom stressors and depressive symptoms facilitate clinical recurrence of herpes simplex virus (HSV) and progression of HIV. METHOD: Meta-analytic techniques were used to review the relations of stressors and depressive symptoms to clinical recurrence of HSV in 16 published studies and to indicators of HIV progression in 19 published studies. The authors calculated average effect sizes, performed fixed effect and random effect inferential analyses, tested for heterogeneous findings, and identified potential moderating variables. RESULTS: Depressive symptoms were associated with a slightly increased risk of HSV recurrence and increased reports of HIV-related symptoms, whereas stressors were not. However, depressive symptoms were not associated with objective indicators of accelerated HIV progression. Stressor studies, especially those that ascertained population-specific life events, found numerical and functional decrements in circulating natural killer cell populations. The candidate moderators identified include, for HSV recurrence, age, sex, and medication status, and for HIV-related symptoms, age, race, disease stage, and co-infection with HSV. CONCLUSIONS: Depressive symptoms, but not stressors, increase the risk of HSV recurrence generally. Depressive symptoms do not appear to accelerate HIV progression ubiquitously, although they are associated with increased reporting of HIV-related symptoms. Future studies that ascertain population-specific stressors should determine whether reductions in cytotoxic lymphocytes influence HIV disease progression. Moreover, researcher should investigate the role of the identified moderators and recognize psychoimmune moderators in existing and novel study groups. These analyses could confirm that certain individuals are especially susceptible to the effects on disease progression of stressors, depressive symptoms, or both.