In this longitudinal study of women and men with HIV infection, we found that incident depression symptoms were associated with subsequent suboptimal adherence. We also found a relatively high incidence of depression symptoms. Our finding that 22% of women and men with HIV infection and no previous depression symptoms developed depression symptoms at follow-up is high. It underscores the importance of ongoing screening for and attention to depression among women and men with HIV infection.
This is the first report that we are aware of that examines the effect of incident depression symptoms on adherence in persons with HIV. Spire et al. (2002) found that a change in median CESD scores over a four month period was associated with non-adherence over the same time period, but because they measured changes in CESD scores, it is not possible to know how many people at each time point had major depression. In a study of men in the Multicenter AIDS Cohort Study (MACS) depression at the start of a six month interval was associated with a decline in adherence over the subsequent six months, but it was not true that the absence of depression was associated with improved adherence (Kleeberger, 2004). Carrieri et al. (2003) found that baseline depression was associated with an inability to maintain adherence at 18 months follow-up in a cohort of injection drug users initially adherent to ARV treatment in France. Our study extends the findings of these previous longitudinal studies, by demonstrating that onset of depression symptoms is associated with increasing rates of suboptimal adherence.
A meta-analysis of depression and adherence to medical care regimens in general (not only HIV ARVs) found that patients with depression had a three-fold higher odds of poor adherence and suggested possible mechanisms linking depression to poor adherence to medical treatments.41
Included in these possible mechanisms were: the feeling of hopelessness which often accompanies depression, social isolation and an absence of social support.15
Any or all of these mechanisms may be operative in individuals with HIV infection. It has been shown that the presence of social support and other psychosocial resources have been associated with increased survival in women with HIV infection42
; improved survival may be a result of improved adherence.
African Americans in our study had a higher risk of decline in adherence over time compared with whites. In contrast, Kleeberger et al. (2004) found that African American race was not associated with a decline in adherence among those with perfect adherence, but did predict continued suboptimal adherence among patients who already had poor adherence, while white race predicted later improvements in adherence in those with poor adherence. Some cross-sectional studies have identified an association between African American race and suboptimal adherence to HAART and others have not.9
Although several studies have highlighted this association, further research is needed to identify the mechanisms by which race and adherence may be related. Studies investigating racial disparities in health care have identified patient-level factors including lack of trust in health care providers and the health care system, and provider-level factors, including unfair treatment, discrimination43
or other aspects of the quality of the doctor-patient relationship, as well as structural factors (e.g., inadequate access to or lower quality of care) which could contribute to racial disparities in adherence. It could also be that unmeasured variables such as skepticism about the efficacy of antiretrovirals, or distrust in the provider or health care system contribute to the findings we observed.
A strength of this study is our stringent criteria for classification of depression based on two visits without depression symptoms followed by two visits with depression symptoms, which makes it more possible to establish a clear temporal relationship between depression symptoms and changes in adherence. There are some study limitations. First, we assessed adherence to HAART through participant self-report, so rates of adherence may be overestimates.44,45
Second, the conservative cutoff we used for depression symptoms, which required screening positive for depression symptoms at two consecutive visits may have missed some people who may have had diagnosable depression at just one visit. Third, this study did not include all possible profiles of depression symptom transitions over the four study visits. For example, participants who reported depression symptoms at all four visits were not included in this analysis. The effects of chronic depression are likely different from those of incident depression. Fourth, although it is possible that prior poor adherence contributed to onset of depression symptoms which in turn contributed to worse adherence, this is clinically unlikely. Furthermore, visit 1 non-adherence was not associated with subsequent development of depression symptoms. Finally, it was not possible to analyze the contribution of treatment for depressive symptoms to adherence outcomes.
The results from this study highlight that in persons with HIV infection, the relationship of depressive symptoms to HAART adherence is dynamic rather than static. Our finding that depression symptom onset is associated with a change to suboptimal adherence supports the need for further research to evaluate the impact of treatment for depression on adherence to HAART. Depression can be effectively treated with medications in patients with HIV infection.46
Some studies have found that mental health therapy with and without anti-depressant medication leads to an increase in HAART utilization in women with HIV infection.47
In addition, some studies have demonstrated the effectiveness of cognitive behavioral therapy in improving adherence.46, 48, 49
Further research is needed to evaluate the impact of psychosocial and pharmacological treatment interventions for depression on clinical outcomes in patients with HIV and to identify interventions that prevent worsening adherence or improve adherence over time.
The results from this study also underscore the importance of ongoing aggressive screening for depression in order to intervene to improve mental health and HAART adherence in patients with HIV infection. For screening to be cost effective and have an impact, it is critical to strengthen referral systems to ensure appropriate treatment of and follow up for depression for patients with HIV and depression, not only because it may improve adherence as well as HAART outcomes, but because of its potential impact on quality of life overall.