Psychology & Psychiatry

Women don't fancy easy-to-seduce men

How men play the mating game is fairly well understood. But the psychological tricks and ploys women might use to attract or deceive men are less clear.

Oncology & Cancer

TrackSig: Unlocking the history of cancer through tumor evolution

A tumor is often made up of different cells, some of which have changed—or evolved—over time and gained the ability to grow faster, survive longer and potentially avoid treatment. These cells, which have an "evolutionary ...

Psychology & Psychiatry

The politics of fear: How it manipulates us to tribalism

The cruel murder of 50 people in New Zealand was another tragic reminder of how humans are capable of heartlessly killing their own kind just based on what they believe, how they worship, and what race or nationality they ...

Psychology & Psychiatry

Exercise can fast-track your workplace well-being – here's how

Exercise has been found to reduce stress, increase positive mood, decrease anxiety and alleviate depression. But you may not know that the emotional well-being associated with exercise is also linked to key attributes that ...

Neuroscience

Sound changes the way rodents sense touch

The brain assigns sensory information from the eyes, ears and skin to different regions: the visual cortex, auditory cortex and somatosensory cortex. However, it is clear that there are anatomical connections between these ...

Health

Always have room for dessert? Here's why

You're stuffed with cheese and olives, crackers and dips. Glazed ham, roast turkey, barbecued prawns. A million salads, roast veggies and your aunt's famous beans. So why is there always room for dessert?

Psychology & Psychiatry

The spotlight of attention is more like a strobe

You don't focus as well as you think you do. That's the fundamental finding of a team of researchers from Princeton University and the University of California-Berkeley who studied monkeys and humans and discovered that attention ...

Neuroscience

Optimized perception in the twilight zone

In the pre-industrial age, twilight was a dangerous time for humans due to higher risk of encountering nocturnal predators. The ability to see in weak light conditions was therefore at a clear evolutionary advantage. Neuroscientists ...

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Evolutionary approaches to depression

Major depression is the leading cause of disability worldwide, and in 2000 was the fourth leading contributor to the global burden of disease (measured in DALYs); it is also an important risk factor for suicide. It is understandable, then, that clinical depression is thought to be a pathology — a major dysfunction of the brain. Yet the epidemiology of clinical depression is something of an outlier when compared to the epidemiology of major dysfunctions of other organs like the heart, liver, lungs and kidneys[citation needed]. In most cases, rates of organ dysfunction increase with age, with low rates in adolescents and young adults, and the highest rates in the elderly. These patterns are consistent with evolutionary theories of aging which posit that selection against dysfunctional traits decreases with age (because there is a decreasing probability of surviving to later ages).

In contrast to these patterns, prevalence of clinical depression is high in all age categories, including otherwise healthy adolescents and young adults. In one study of the US population, for example, the 12 month prevalence for a major depression episode was highest in the youngest age category (15–24 year olds). The high prevalence of depression is also an outlier when compared to the prevalence of major mental retardation, autism, and schizophrenia, all with prevalence rates about one tenth that of depression, or less.

The common occurrence and persistence of a trait like clinical depression with such negative effects early in life is difficult to explain. (Rates of infectious disease are high in young people, of course, but clinical depression is not thought to be caused by an infection.) Evolutionary psychology and its application in evolutionary medicine suggest how behaviour and mental states, including seemingly harmful states such as depression, may be past adaptations to recurring reproductive problems faced by our ancestors, actually having improved however disadvantageous in the modern world, the fitness of either the individual or their relatives. It has been argued, for example, that Abraham Lincoln's life-long depression was a source of insight and strength. Some even suggest that "we aren’t designed to have happiness as our natural default" and so a state of depression is the evolutionary norm.

The following hypotheses attempt to identify a benefit of depression that outweighs its obvious costs. All take as their starting point the fact that one of the most potent, well-established causes of major depression is a severe negative life event.

This text uses material from Wikipedia, licensed under CC BY-SA