“We found that a greater proportion of time spent with depression increased the risk of missed primary care appointments and lack of viral suppression in a dose-response manner,” comment the authors. “Mortality rates also increased with greater depression burden, with a suggestion of a threshold association such that even modest increases in time spent with depression, amounting to 1 in 4 during follow-up, approximately doubled the mortality risk.”
Prompt diagnosis and shortening the time patients spend with depression could have significant HIV-related benefits, suggest the authors.
With an estimated prevalence of between 20 and 40%, depression is very common among people with HIV. As well as being a serious medical condition in its own right, depression in the context of HIV has been associated with poor adherence to antiretroviral therapy (ART), missed appointments, the progression of HIV disease and increased mortality risk.
Previous research has focused on characterising the severity of depression and its relationship with HIV outcomes. Depression in people with HIV is often chronic, but the association between chronic depression and outcomes has received little attention. Investigators designed a study to see if increasing proportion of time spent with depression was associated with poorer engagement with key points in the HIV care continuum – attending appointments, viral suppression (below 75 copies/ml) and all-cause mortality.
The observational study involved 5927 people who received routine care at eight sites across the United States between 2005 and 2015. Depressive symptoms were assessed every six months. For each person, the investigators calculated the proportion of days with depression (PDD): a marker of chronic depression.
Approximately half the participants were white, 84% were male and the median age was 44 years. Two-thirds of participants had a baseline CD4 cell count above 350 cells/mm3, three-quarters were taking ART and 63% of the entire cohort had fully suppressed viral load.
Participants were followed for 10,767 person-years. During this time, individuals spent an average of 14% of days with depression. Just under a third of people (31%) had no days with depression, with 4% reporting depression every day.
“Even modest increases in the proportion of time spent with depression led to clinically meaningful increases in negative outcomes."
There were 158 deaths during follow-up (1.5 deaths per 100 person-years). Approximately a fifth (19%) of scheduled appointments were missed and 22% of viral load measurements were above the limit of detection.
Each 25% increase in the proportion of days with depression was associated with an 8% increase in the risk of missing a scheduled appointment (RR = 1.08; 95% CI, 1.05-1.11), a 5% increase in the risk of having a detectable viral load (RR = 1.05; 95% CI, 1.01-1.09) and a 19% increase in mortality risk (HR = 1.19; 95% CI, 1.05-1.36).
Compared with people who spent no time with depression, those who were depressed all the time, had a 37% increase in the risk of missing appointments, a 23% increase in the risk of having a detectable viral load and a doubling in their mortality risk (HR = 2.2; 95% CI, 1.20-3.42).
“These findings, which suggest that systematic screening and enhanced treatment to shorten the duration of depressive illness may have multiple benefits, stand in contrast with the trend of HIV treatment guidelines towards less frequent monitoring of patients whose disease is stable with treatment,” comment the authors. “Even modest increases in the proportion of time spent with depression led to clinically meaningful increases in negative outcomes. These findings suggest the importance of promptly identifying and treating depression among adults living with HIV to shorten the course and prevent the return of depressive illness and ultimately improve their clinical outcomes.”