Self-medicating for psychiatric disorders foreshadows substance use disorder

Many people with mood and anxiety disorders (MD/AD) self-medicate to relieve symptoms, thus heightening the risk for comorbid substance use disorder (SUD), according to a recent review article published in Depression and Anxiety. Providing alternative coping strategies for patients with MD/AD may reduce self-medication (SM) and subsequent SUD in these patients, researchers reported.

“The literature currently lacks a synthesis of the epidemiological literature examining SM with alcohol and/or drugs for MD/AD symptoms,” wrote authors led by Jitender Sareen, MD, professor, Department of Psychiatry, Psychology, and Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.

The comorbidity of MD/AD and SUD is confirmed by previous research. Specifically, the chance of having one disorder when the other is present is between two and five times more likely. This resulting co-occurrence amplifies disease severity, suicidality, impairment, and assistance-seeking.

To treat and prevent the co-occurrence of MD/AD and SUD, the mechanisms underlying this relationship must be identified. One popular explanation is the self-medication hypothesis (SMH), which suggests that people with MD/AD use alcohol and drugs to cope, and as these people use more substances, the risk of independent SUD increases.

For this review, Dr. Sareen and colleagues mined 22 research articles to discover the temporal association between MD/AD and SUD in the general population, as well as the prevalence and correlates of SM. Importantly, the researchers looked at the temporal link between MD/AD and SUD in studies that employed both self-reported SM measures and those that did not. According to the reviewers, limiting the review to studies that only include self-reported SM measures would likely underrepresent the true prevalence of SM in the general population.

The team found that between 21.9% and 24.1% of people with MD/AD report self-medicating with alcohol, drugs, or both. Factors that contribute to the prevalence of SM included male sex, younger age, white race, and being separated, divorced, or widowed—but, surprisingly, not education or income status.

Data from cross-sectional studies without measures of SM suggested bi-directional relationships between MD/AD and SUD. Thus, SM is a possible mechanism underlying the comorbidity between MD/AD and SUD—but not the only mechanism. Moreover, longitudinal data consistently showed that people who self-medicate for MD/AD are more likely to go on to develop SUD.

“The current psychiatric ‘gold standard’ model of care is concurrent treatment of MD/AD and SUD,” the authors wrote. “Therefore, addressing both MD/AD and SUD is an important treatment goal and may lead to improved treatment outcomes overall.”

The reviewers conceded that one limitation of the current review is that assessing SM via self-report measures could foster bias. For instance, subjects may not want to report this behavior, forget such behavior, or fail to recognize such behavior is related to MD/AD. If this limitation is valid, then the current study would underestimate the strength of the link between MD/AD and SM. Although either physician-based reporting of SM or reports by family members could better estimate the frequency of SM in these subjects, implementing such approaches would pose a challenge in population-based surveys.

“It is possible that addressing SM could be targeted to prevent the development and persistence of a threshold SUD,” the researchers concluded. “Clinicians and health-care providers should screen for SM among those presenting with MD/AD and provide ‘gold standard’ concurrent treatment to address SM behavior and MD/AD simultaneously.”

This research was supported by funding from the Canadian Institutes of Health Research.