Can Depression Treatment Reduce Cardiovascular Risks?

A new study published in the Journal of Brain, Behavior, and Immunity looked at the effect of modernized collaborative care for depression on depressive symptoms and cardiovascular disease risk biomarkers.

“We set out to determine whether treating depression, a psychological risk factor for cardiovascular disease (CVD), could reduce the risk of developing CVD in the future, like treating high blood pressure and high cholesterol,” study author Jesse C. Stewart told us. “Our study, the eIMPACT trial, was based on more than three decades of research showing that people with depression are at elevated risk of developing CVD, similar to people with traditional CVD risk factors.”

In addition, depression has been linked with biological (e.g., systemic inflammation) and behavioral (e.g., smoking) factors that are known to contribute to the development of CVD. Therefore, the research team’s hypothesis was that successful depression treatment would reduce the CVD risk of people with depression by improving the biological and behavioral pathways linking depression and future CVD.

“I have been conducting studies on the depression-to-CVD relationship since I was a postdoc in cardiovascular behavioral medicine research at the University of Pittsburgh from 2003-2006,” Stewart told us. “While prior clinical trials have examined if treating depression in cardiac patients improves their medical prognosis, no prior studies tested whether treating depression earlier in the natural history of CVD (i.e., before the occurrence of heart attacks and strokes, which are late-stage events) yielded cardiovascular benefits. To me, this seems like a critical knowledge gap and an important missed opportunity to potentially improve the lives of people with depression (approximately 10% of the U.S. population).”

The research team conducted the eIMPACT trial, which was a five-year randomized controlled trial funded by the National Heart, Lung, and Blood Institute of the NIH (2015-2020). It is the most definitive clinical trial to date testing whether successful depression treatment reduces risk of CVD.

More specifically, the eIMPACT trial was designed to determine whether successful depression treatment improves CVD biomarkers (i.e., measures of endothelial dysfunction, autonomic nervous system dysfunction, systemic inflammation, and platelet activation) – which are predictors of future CVD events, such as heart attacks and strokes.

Participants were 216 primary care patients with depression and elevated CVD risk from a safety-net healthcare system in Indianapolis.

“Of note, there was good representation of women (78%), Black people (50%), and people with low incomes (46% <$10,000/year),” Stewart told us. “These participants were randomly assigned to 12 months of either our eIMPACT intervention or usual primary care for depression.”

The eIMPACT intervention is the modernized collaborative care intervention for depression in which a multidisciplinary team (our Master’s-level depression clinical specialist, our psychiatrist, our primary care liaison, and the patient’s usual primary care provider) delivers established depression treatments consistent with patient preference. Treatment options were internet cognitive-behavioral therapy [CBT], telephonic CBT, and/or antidepressant medications with no or minimal adverse cardiovascular effects. Nearly all treatment was delivered remotely from a centralized location by a depression clinical specialist. Usual primary care for depression in the safety-net healthcare system was a form of integrated, team-based care with primary care providers supported by behavioral health clinicians embedded in the clinics and psychiatrists affiliated with the clinics.

Depressive symptoms and the CVD biomarkers were assessed at baseline (before the treatment period) and at 12 months (the end of the treatment period).

“We found that participants in the intervention group showed moderate-to-large and clinically meaningful improvements in depressive symptoms,” Stewart told us. “To illustrate, 43% of intervention participants, versus 17% of usual care participants, had a ≥ 50% reduction in depressive symptoms. However, we found no treatment group differences for the CVD risk biomarkers. Contrary to our hypothesis, the CVD risk biomarkers did not improve with successful depression treatment. In other words, the intervention effect on depression did not trickle down to the CVD risk biomarkers.”

As the hypothesis was not supported, the team was surprised by the results. Nonetheless, they have proven quite informative on two fronts.

First, the results indicate that depression treatment alone is not sufficient to reduce the elevated CVD risk of people with depression back to that of the general population.

“More must be done,” Stewart told us. “Alternative strategies are needed. In addition to treating depression, I believe we need a combined intervention approach – an approach that simultaneously treats depression and the biological and behavioral pathways linking depression to future CVD.”

Second, the team’s effective depression intervention – modernized collaborative care for depression – could inform the design and delivery of contemporary integrated care approaches.

“Our intervention highlights the potential utility of eHealth interventions and of centralized, remote delivery in safety net healthcare settings,” Stewart told us. “Our intervention is feasible, acceptable, and effective. For patients, our intervention is convenient and accessible. For healthcare systems, our intervention is resource sparing, as it harnesses tech to minimize personnel, space, and training resources needed to deliver high quality care.”