The Syndemic Framework: Enhancing Understanding of the Root Causes of Disease

By Iris Smith, PhD.

The Social Determinants of Health Framework (SDOH) is familiar to most preventionists. The SDOH framework helps us to conceptualize the social environments that influence individual beliefs and behavior. However, it alone does not help us understand how the social determinants interact with individual and community-level factors to affect health outcomes. It also does not consider the macro-level influences such as the political climate, racism, geospatial position, and how these factors interact and overlap to affect individual health outcomes.

The Syndemic Framework is an emergent theory that attempts to explain how the presence of other diseases, social conditions such as chronic non-communicable diseases, mental health problems, behavioral conditions, toxic exposure, food insecurity etc., act together to worsen the spread of disease.

The term “syndemic” was originally used by Singer (2009) to describe how substance misuse, violence, and AIDS are interconnected.1 The criteria of a syndemic are: (1) two (or more) diseases or health conditions cluster within a specific population; (2) contextual and social factors create the conditions in which two (or more) diseases or health conditions cluster; and (3) the clustering of diseases results in adverse disease interaction either biological, social or behavioral, increasing the disease burden of affected populations.2

Although recent increases in opioid use and its association with overdoses and deaths can be framed as a syndemic, most of the research has focused on individual risk factors. The upstream drivers of the opioid epidemic include social and community level conditions such as low per capita income, physician prescribing behavior, ineffective pharmaceutical regulation, and high unemployment. Macro level structural factors such as housing, stigma, criminal justice policies, and discrimination are also drivers of the epidemic. Opioid-related syndemics are driven by commercial interests that emerge in communities facing social and economic disadvantage. The rise in intravenous drug use also resulted in a rise in infectious diseases such as HIV and Hepatitis C. The synergy between these factors worsens the impact of the epidemic on individuals and communities.3

The syndemic framework examines the context of health conditions to determine points of intersection and synergy rather than focusing on individual multi-level factors in isolation. For example, treatment outcomes for individuals involved in the criminal justice system are complicated by lack of access to evidence-based treatment in correctional settings. The COVID-19 pandemic intersected with existing health disparities, mental health problems, and systemic inequalities which contributed to disproportionate effects in vulnerable populations.4 The syndemic framework helps illuminate for prevention the multi-level root causes of disease that impact vulnerable populations and increase the potential need for upstream interventions that impact multiple health outcomes.


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1 Singer, M. (2009). Introduction to syndemics: A critical systems approach to public and community health. John Wiley & Sons.

2 Singer M, Bulled N, Ostrach B, Mendenhall E (2017).  Syndemics and the Biosocial Conception of Health.  The Lancet; 389, March 4, 2017.

3 Long J, Mendenhall E, Koon AD (2023). Disentangling Opioids-Related Overdose Syndemics:  A Scoping Review.  International Journal of Drug Policy 119; pg. 104152/

4 Shelke A, Selke S, Acharya S, Shukla S. (2023).  Synergistic Epidemic or Syndemic:  An Emerging Pattern of Human Diseases.  Cureus 15(11). Published online 2023 Nov 5. doi: 10.7759/cureus.48286

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