It must be incredibly difficult to imagine the maddening reality of living with a mental illness for someone who has never experienced it first hand. We all feel blue from time to time, but few ever experience the debilitating inability to feel joy, constant fatigue, and mind-numbing impediment of thought accompanied by major depressive disorder. William Styron once described it as being attached to a bed of nails which one carries around wherever they go, and in my experience this is strikingly accurate.
Yet for all its unpleasantness the noonday demon seems to pose an evolutionary paradox. Darwin’s legacy was that evolutionary pressures shape not only our physical characteristics but our mental and behavioural processes as well. This being the case, how is it that an illness characterized by a myriad of symptoms so obviously detrimental to evolutionary fitness – decreased cognitive function, a loss of interest in sex, socializing, and exercise, not to mention suicide – has persisted?
Not only has depression not been wiped out through the course of natural selection, it is now – and I believe rightly so – considered an epidemic. The global burden of depression is soaring; the latest estimates by the World Health Organization place the global prevalence of depression at three hundred and fifty million worldwide , and in the last forty five years alone the annual rate of suicide has increased by sixty percent . Despite our best efforts in the development of behavioural therapy, pharmacological treatment, and psychological theory the depression epidemic shows no signs of letting up. We are losing the fight against depression.
Continue reading Evolutionary Psychology Offers A Fresh Perspective On Depression
“Conscious experience is at once the most familiar thing in the world and the most mysterious. There is nothing we know about more directly than consciousness, but it is far from clear how to reconcile it with everything else we know.”
– David J. Chalmers
WE ARE ALL intimately familiar with that voice in our heads, nagging as we reach for a second helping of chocolate eggs in the wake of Easter, and judging as we have to settle for a looser belt hole a week later. We are all also accustomed to the different masks we wear in various social situations. I would be ruthlessly mocked could my close friends see the way I behave around my girlfriend, snuggled on the couch on a Sunday night, and my parents would be hard pressed to recognize me. But this apparent discontinuity is a perfectly normal aspect of human existence – psychologists have long known that situation exerts a significant influence on personality – and I have never experienced anything which would seem to indicate that there was more than one self calling the inside of my skull home. As a matter of conscious experience, I am just as much me whilst goofing around with my girlfriend as I am typing this essay and sipping green tea. But am I really? As a result of a fascinating avenue of inquiry involving patients who have had the hemispheres of their brain surgically separated, psychologists, cognitive scientists, and philosophers have begun to argue that there is every reason to believe in the divisibility of consciousness – the existence of a separate centre of consciousness in each of the divided hemispheres – and you and I might not be as different to these patients as we think.