By Ms. Cynthia Kim
DO Candidate, 2017
College of Osteopathic Medicine
Depression, a pathological state defined by low mood or anhedonia, is universally viewed in a negative light as a mood disorder. Despite the view of depression as an unfavorable defect, there seems to be additional research with strong arguments in favor of depression developing as an adaptation. As the most complex organ in the body, the brain holds monumental complexities, which are reflected in the inherently difficult analysis of depression. Given the brain’s complexity and its residual effects on the rest of the body, a number of researchers have embarked on efforts to identify the possible causes and benefits of depression. In the following paragraphs, we will explore the adaptation hypothesis using Dr. Randolph Nesse’s article “Is Depression an Adaptation?”
Dr. Nesse makes a number of persuasive arguments for the adaptive quality of depression. He acknowledges many possible ways in which actions exhibited by depressed patients may have evolved out of necessity such as communicating a need for help, signaling yielding in hierarchy conflict, and fostering disengagement from unreachable goals. He argues that low mood provides a coping mechanism, allowing one to detach from unfavorable situations. The disengagement from unreachable goals provides individuals with exit opportunities and allows them to conserve their efforts in favor of a more attainable pursuit. The advantage of preservation of energy in low mood is also demonstrated by the theory of foraging. An organism will give up a patch of land and search for an alternative source when the rate of return of food is low. Alternatively, the organism’s continued fruitless efforts to forage for food in a depleted patch are detrimental to its survival.
Aligning with Dr. Nesse’s view of depression as an adaptation, one can compare the functional qualities of depression with that of physical muscle movements. The muscles in your body have adapted in a multitude of ways to manage the daily rigors placed upon them. Similar to your muscles, your brain is expected to handle and survive varying levels of stress. Depending on one’s medical and genetic history, clinical depression can occur when an individual faces an extended period of increased stress that exceeds their personal limit. This phenomenon mirrors that of muscle injuries when individuals over-exert their bodies. When placing excessive strain on a muscle, your golgi tendon sends a message to the brain, inhibiting contraction and relieving tension. If the individual decides to push the limits of this stress management, physical injuries occur. Similarly, low mood creates a feedback response to disengage from the stressful situation. The inability to disengage for an extended period of time can lead to clinical depression.
The continued exploration of low mood and depression as positive adaptations is crucial to our understanding of the human psyche. As our society continues to transform from a physically dominated one to a mentally rigorous one, the ability to cope with stress and manage emotional well-being will be increasingly valuable. Thus, we can expect to see not only increased occurrences of diagnosed depression but also increased ability to handle mental challenges across individuals. Continued research on this topic will ideally contribute to our ability to prevent, correctly diagnose, and treat those suffering from depression or low mood.