Depression and Evolution

Depression is one of the most common mental health disorders and it is estimated that around 15% of adults deal with depression at some point in their lives. It can cause loss of motivation, loss of enjoyment and affect performance in several areas of life. Yet some scientists believe that depression could actually be an evolutionary benefit, promoting rumination and allowing people to address complex problems in their lives. In short, depression could be good for you.

Depression as Mental Illness

Clinical depression is predominantly viewed by mental health practitioners as a mental illness. A problem in its own right, it is also a symptom of more complex disorders such as bipolar, cyclothymia and borderline personality disorder.

Symptoms of depression include, among others:

  • Continuous low mood
  • Low self-esteem
  • Lack of motivation at work and at play
  • Lack of enjoyment in day to activities
  • Lack of energy
  • Insomnia and related sleeping disorders

In general depression is characterized by long periods of sadness and apathy that can make it particularly difficult for an individual to perform in the professional, social and personal lives. There is a great body of research which shows that depression can impair cognitive functions, supporting the view that depression is a mental illness.

Depression and Evolution

However, Andrews and Thomson (2009) in Psychological Review suggest that depression is in fact an evolutionary adaption for dealing with complex problems. They liken it to an immune response. When a person has a fever, it can cause significant impairment and distress in multiple areas of the person’s life, but it is not considered a biological dysfunction. The symptoms of fever are the result of an adaptive mechanism that exists in order to coordinate the immune system in the case of an infection.


Depression can also be considered in this way. A complex problem in a person’s life can be likened to an invading illness and depression is the immune-response that deals with the infection. Research has shown that the physiological and cognitive changes which occur during depression could increase an individual’s problem solving capacity even though it affects their everyday motivation and performance.

Physiological and Cognitive Effects of Depression

Several key changes in the bodies physiological and cognitive function are identified during depression that help a person deal with the root cause. These include:

  • The information exchange in the brain is slowed. This allows the brain to break down the problem into smaller chunks and perform complex analysis upon it.
  • Energy and nutrient resources are routed to those areas of the brain dealing with the problem. A side effect of this is a loss of energy elsewhere.
  • The problem solving routine is given greater priority for cognitive resources. This causes a loss of interest in other activities as our thoughts are preoccupied with the problem at hand.

Overall, the reaction is similar to that which occurs during stress. A stress reaction is the body’s way of handling a perceived threat or pressure situation; heart rate and blood pressure are increased and resources are directed to vital organs to increase short term performance. Stress over a long period can however be detrimental to health.

With depression, resources are directed towards the areas of the brain best able to deal with the problem. This improves problem-solving ability but if allowed to persist can have detrimental long term effects.

Coping with Depression

Many psychological consider that a patient’s preoccupation with their problems during depression is pathological and must be addressed as a first step to a cure. However, the alternative theory outline above suggests that this preoccupation is the very reason for the other symptoms of depression and if the preoccupation is the body’s way of producing a cure.

While coping with depression every day can be difficult, it is possible that resolving it by addressing the cause can lead to overall improvement in the quality of the patient’s life when comparisons pre- and post- depression are made. The work remains theoretical but does make room for discussion on the best ways of dealing with depression, as well as associated disorders such as bipolar and cyclothymia.

Depression, then, is not necessarily a bad thing. It can help to identify and solve important problems that an individual encounters that can lead to an overall improvement in our quality of life. While the majority of mental health practitioners still view it as an illness, alternative ideas about depression do persist and there are many different ways that it can be addressed.

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