Our findings provide further evidence of the under-treatment of depression in primary care settings, including by general medical providers and medical specialists (infectious disease providers). However, among both HIV-infected and uninfected patients in whom depression is detected, depression treatment is initiated quickly and typically at the assessment visit for HIV-infected patients with severe depression. The finding that ID providers treat severe depression more quickly may reflect either biological differences among patients by HIV serostatus or practice characteristic differences between ID and GM clinics. For example, ID providers have more time with patients as they have longer visit durations and smaller patient panels. In this study, uninfected patients in care at GM clinics were no less clinically complex than HIV-infected patients in care at ID clinics. Compared to HIV-infected patients, more uninfected patients had severe depression, characteristics that are usually associated with depression treatment (being female, having higher income, employed, and having a partner),27
and conditions common in depressed patients that could serve as depression screening indicators (post-traumatic stress disorder28
, and coronary artery disease30
). Despite these potential depression treatment correlates among uninfected patients, time to depression treatment was significantly shorter in HIV-infected patients with severe depression.
In this study, African Americans and Hispanics received delayed depression treatment, consistent with previous reports of under-detection and under-treatment of depression among non-white patients31,32
. This disparity occurring in the VA (an integrated system) suggests that this difference is not entirely due to barriers to access to care. Both psychiatric and medical comorbidity also appear to have a significant impact on time to depression treatment. For example, hepatitis C infection complicates depression treatment33
and in this study was associated with delay in depression treatment initiation regardless of HIV serostatus. Similarly, coronary artery disease was also associated with delay in depression treatment, perhaps suggesting the impact of competing demands on primary care providers34
. Neither a history of alcohol abuse nor baseline AUDIT scores were associated with a delay in depression treatment; while, history of illicit drug use was more common among HIV-infected patients, it did not significantly affect time to depression treatment. Surprisingly, among depressed HIV-infected patients, well-controlled HIV infection (i.e., higher CD4 counts, lower HIV viral loads, being prescribed ART, or being adherent to ART) was not associated with shorter time to depression treatment.
Competing demands impact detection and treatment of depression in primary care35
. Among patients with untreated depressive symptoms in this study, uninfected compared to HIV-infected patients had more comorbidities (although did not achieve a statistically significant difference) but had half as many primary care visits in the year prior to assessment. The likelihood of depression treatment might increase if these patients had more frequent visits. Indeed, in this study, we found that more GM visits in the year prior to assessment was associated with a greater likelihood of depression treatment among depressed uninfected patients. Our finding that having more comorbidities was associated with a greater likelihood of depression treatment among depressed uninfected patients was inconsistent with some previous literature suggesting that depression treatment occurs less frequently among depressed patients with comorbid conditions14
; however, patients with multiple comorbidities typically have more frequent visits with medical providers, offering more encounters for depression to be diagnosed and treated. Furthermore, the HIV-infected group in this study had well-controlled HIV, potentially allowing ID providers more time to address other conditions, such as depression. These factors could have accentuated the effects of competing demands on detection and treatment of depression more among uninfected compared to HIV-infected patients. Consequently, compared to ID providers, GM providers may have less time to nurture a working alliance with patients that fosters an environment conducive not only to detecting depression, but also formulating depression treatment plans acceptable to patients. If these conditions are fulfilled, time to depression treatment could improve, as suggested by our study’s median time to depression treatment being 7 days.
We have previously shown that ID and GM providers are equally likely to under-diagnosis and under-treat depression15
, and ID compared to GM providers are less comfortable in treating depression20
. Despite these provider characteristics, time to depression treatment was shortest among HIV-infected patients; however, percentage of patients treated for depression and type of depression treatment (antidepressant or referral to mental health clinic) was not significantly different by HIV serostatus and depression severity.
Our findings should be interpreted in the context of our study’s limitations. First, generalizability may be limited since patients who obtain care through the VA are not representative of all patients in care; however, only 9% of approached patients, regardless of HIV serostatus, refused participation in VACS17
. Second, depression classification was based on a screening instrument rather than diagnostic interview; however, patients with major depressive disorder are six times more likely to score 9 or higher on PHQ-9 testing than patients without major depressive disorder19
. Third, detection of comorbid conditions was based on ICD-9 codes, and a count of comorbid conditions may not adequately capture clinical complexity. Fourth, providers were not aware of their patients’ PHQ-9 scores; however, baseline PHQ-9 was administered during either GM or ID visit. Finally, our treatment definition does not adequately capture treatment complexity. Identification of treatment was based on VA utilization; patients may have obtained mental health treatment outside the VA. Also, referred patients could have cancelled or not attended their mental health visit. Furthermore, antidepressant prescription receipt does not indicate medication adherence. Moreover, patients could have declined depression treatment.
In conclusion, the majority of depressed patients in primary care do not receive treatment for depression. This study demonstrates that if depressed patients are not treated for depression on the day that they have symptoms severe enough to screen positive for depression, then ID and GM providers are unlikely to initiate depression treatment in the subsequent 90-day period. Difference between time to depression treatment among HIV-infected and uninfected patients may reflect differences in delivery of clinical care and suggests a need to evaluate the negative consequences of increasing demands on primary care providers.