Increased training in substance use disorder identification and frontline treatments may provide value for primary care patients.

Primary care patients often have behavioral health concerns that complicate medical care and  health outcomes. Primary care physicians who address these concerns for their patients may provide more benefits than specialists.

In a study published in the Journal of Primary Care & Community Health, Mark McGovern, PhD and colleagues examined the correlation between substance use disorder and increased depression severity, both longitudinal and cross-sectionally among patients (N=2,409) from 41 geographically diverse primary care clinics across the United States. “We aimed to evaluate the impact of integrating behavioral health care within the primary care context,” Dr. McGovern says. “The main focus of the present study was to examine the role of substance use, including  alcohol and other drugs, on patients’ depression symptoms.”

Substance Use May Drive Depressive Symptoms

Patients in the study completed surveys about medical and behavioral concerns. Practices and healthcare professionals were not aware which of their patients completed the survey. “We expected depression to be a common concern among patients,” Dr. McGovern says. “But from existing research and epidemiological studies, we also understood that substance use may drive depressive symptoms. Using data from these ‘secret shopper’ surveys, we focused on the relationship between depression and substance use, at each timepoint, and over time.”

Although universal screening rates for substance use problems are increasing in primary care practice, most healthcare systems and practices screen (and therefore, initiate treatment) only for depression, according to Dr. McGovern. “This study highlights the clinical need for practices to either consider universal substance use screening or to consider such screening for patients with severe depression, as well as for patients not responding to frontline treatments such as anti-depressant medications,” he says, adding that substance use disorder likelihood is highly associated with depression severity cross-sectionally at two timepoints and longitudinally over time (Figure).

Barriers to Addressing Substance Use Problems in Primary Care

“Historically, primary care professionals have been reluctant to address substance use problems among patients because of perceived lack of patient motivation, healthcare professionals’ reluctance to deliver addiction medications, and often limited options for referrals to addiction medicine specialists,” Dr. McGovern points out. In contrast, he adds, identifying and treating depression in primary care is normative.

“Our research suggests that perhaps increased training in substance use problem identification and frontline treatments might be beneficial,” he says. “It is also recommended that primary care professionals consider underlying substance use when patients do not seem to be improving with standard depression interventions.”

Since the study involves secondary analyses of patient-reported outcomes from a large parent study, the researchers cannot draw causal inferences, Dr. McGovern notes. “There are meta-analyses that conclude that treating depressive symptoms will not impact substance use problems, and that there is a greater chance by addressing substance use that depression will improve,” Dr. McGovern says. “Nonetheless, future research must examine this topic more rigorously. By doing so, we may increase the chances for better outcomes for our patients who suffer from both depression and substance use issues.”