Without mental disorders, we’d probably be extinct
We may be labelling more of the normal spectrum of human traits as abnormal
There seems to be an epidemic of mental disorders in our modern age, with more and more people acquiring a psychiatric diagnosis. In a recent Ipsos survey, 49 per cent of Canadians reported having experienced a mentalhealth issue at some point in their lives.
What’s going on?
Among several possible explanations, it could be that we’re labelling more of the normal spectrum of human traits as abnormal. Mental disorders are usually considered abnormalities or illnesses, categorically different from “normal” human experience. Part of the reason we have difficulty drawing a sharp line between mental disorders and normal traits may be because most mental disorders are more extreme versions of normal traits.
When psychiatrists call something a disorder, part of what they are considering is whether the particular difficulty is causing significant and sustained impairment in functioning or significant distress. While mental disorders certainly can be disabling or distressful, in many cases they may actually just be part of the spectrum of human diversity — just a little further toward the end of the continuum.
Imagine you’re a hunter-gatherer in Paleolithic times. Is it better to be a cautious type of person or an exploratory risktaker?
Better to be someone who spends time meticulously attending to details such as studying whether this is the hoof print of an injured animal — or someone who swiftly takes in the big picture of the surroundings and makes snap decisions?
Different environmental circumstances will favour different types of people: in some environments it’s caution and attention to detail, in others, risk-taking, rapidly getting the gist of the big picture and making quick decisions. It takes all types of individuals to increase the chances for a population to survive in unpredictable, ever-changing environments.
Take anxiety. A certain amount of it motivates us, and alerts us to be cautious. But some people are prone to experience more anxiety than others, causing those individuals greater distress and impairment in their functioning.
Those people might be considered to have a moderate “disorder.” They may be very sensitive, excessively prone to nervousness, stress and worry, emotionally reactive and uptight. Their sensitivity can be a positive trait too — they may be very emotionally attuned.
Those with the most severe, disabling anxiety are at the extreme end of the population spectrum for this trait and can be considered to have a severe disorder. At the other end of the curve are people who actually experience unusually little anxiety. This isn’t necessarily a good thing. Think of these people as relatively fearless and emotionally under-reactive. These people may take excessive risks and may be emotionally insensitive. While they do not suffer or seek professional help, they are more likely to die in an accident. At the same time, these types of people would have been more likely to explore and colonize new territories, which was crucial for the survival of the species.
Since the environment changes unpredictably, a population with diverse types of people will be more likely to survive as a group in the long run than will a population whose members are all very similar to each other. In the environment in which our species evolved for most of its history, having a little or lot of anxiety would both have been advantageous in different situations. All types were needed for the group to survive and thrive.
But why the apparent modern epidemic of mental illness?
Younger generations may be more likely to label personal difficulties as mental-health issues. It’s also possible that our fast-moving modern life is one culprit. Smartphones and social media are very recent and fastchanging inventions: cultural and technological change may have outstripped our capacity to handle the stresses they cause.
Modern societies have unusually skewed environments — highly structured, organized, specialized schools and detailoriented jobs. These environments favour those with more attention to detail and the other traits associated with being a focused person. Therefore, a larger proportion of people are experiencing their relatively short attention span as a “disorder” impairing their functioning and are diagnosed with an Attention Deficit Disorder (ADD). People who are excessively focused have difficulties too. They tend to be finicky, obsessive, and perfectionistic, and may tend to miss the big picture.
But why do extreme traits exist at all?
While extremes of a trait might seldom be advantageous, they are an inevitable result of genetic diversity. Statistically, some individuals in every generation will inherit more extreme versions of traits at either end of the spectrum. You can’t have a bell curve distribution of traits without the two extremes or “tails” of the curve. Diversity of traits is essential for a species to survive and evolve.
If this diversity, and the resulting mental illnesses, didn’t exist, we would have gone extinct as a species a long time ago.
Dr. Ralph Lewis is an Assistant Professor in the Department of Psychiatry at the University of Toronto and author of Finding Purpose in a Godless World. Dr. Benoit H. Mulsant is Chair of the Department of Psychiatry at the University of Toronto.