Depression is a complex and multifaceted disorder within the realm of mental health. It is affecting an estimated 280 million people worldwide, including around 5% of adults globally. The condition can lead to significant challenges in daily life, impacting work, relationships, and overall quality of life. Despite the availability of treatment, over 75% of individuals in low- and middle-income countries receive no treatment for their mental disorders, highlighting a significant gap in care. Depression also increases the risk of suicide and is associated with several physical health issues, including cardiovascular disease and diabetes. For comprehensive information, refer to the World Health Organization’s fact sheets on depression.
My journey into understanding depression, much like the transition from the structured world of code to the nuanced realm of compassion, has led me to explore the mechanisms that underlie this condition. Today, I would like to share an insightful framework for understanding depression’s etiology: the causal pie model. The causal pie model is an epidemiological concept that visualizes the causation of diseases as a pie, where each slice represents a different causal factor. For depression, this means recognizing that no single factor — be it genetic, environmental, psychological, or social — can independently cause depression. Instead, it’s the unique combination of these slices that completes the pie, leading to the manifestation of depression in an individual.
Depression is not just about feeling sad; it involves a combination of many factors that vary from one person to another. To further complicate matters, the subjective nature of depression means that no two individuals experience it in the same way. This is where depression scales come into play, offering tools to quantify and understand the severity and nature of depressive symptoms. Three commonly used scales are the Beck Depression Inventory (BDI), the Hamilton Depression Rating Scale (HDRS), and the Patient Health Questionnaire-9 (PHQ-9). Each of these scales provides a different lens through which to view depression, much like varying slices of the causal pie.
To help explain this complexity, let’s talk about how a commonly used depression scale, the PHQ-9, helps us understand depression better. PHQ-9 is a brief self-report tool, helps in the diagnosis and monitoring of depression, emphasizing the functional impact of depression on one’s daily life. It asks about 9 different symptoms of depression over the last two weeks, including:
- Little interest or pleasure in doing things.
- Feeling down, depressed, or hopeless.
- Trouble sleeping.
- Feeling tired or having little energy.
- Poor appetite or overeating.
- Feeling bad about yourself or that you are a failure.
- Trouble concentrating on things.
- Moving or speaking so slowly that other people could have noticed, or the opposite – being so fidgety or restless that you have been moving around a lot more than usual.
- Thoughts that you would be better off dead or of hurting yourself in some way.
The PHQ-9 shows us that depression isn’t just about feeling sad. It can affect our interest in activities, our energy levels, our appetite, and even our thoughts about ourselves and our life. Using the causal pie model alongside tools like the PHQ-9 helps us appreciate the complexity of depression. For example, two people might both score high on the PHQ-9, indicating they have severe depression. But the causes behind their depression—the slices of their causal pies—might be completely different. One person might be dealing with the loss of a loved one, while another might be struggling with long-term unemployment.
This complex understanding emphasizes the need for personalized treatment strategies. Just as no single slice can complete the pie, it tells us that there’s no one-size-fits-all solution to treating depression. As we continue to navigate the complexities of depression, let us do so with an open mind and a compassionate heart, recognizing the diverse factors that contribute to this condition and the unique experiences of those it affects. In doing so, we not only deepen our understanding of depression but also take a step closer to offering more effective, personalized care to those in need.
Photo by Diliara Garifullina via Unsplash
