Sep 12 2009
The Questionable Human Propensity for Mental Illness
A new study out of the UK and New Zealand has found that “common mental disorders” may be more common than previously thought. Perhaps twice as common.
The mental disorders in question include anxiety disorders, depression, and substance dependency. The reason for the difference in calculations? While many studies have relied on cross-sectional data(measuring all age groups at one time) provided by hindsight self-reports, newer findings have relied on longitudinal studies (tracking individuals for years and years).
A sample finding -
The best retrospective studies [looking backwards], the US National Comorbidity Surveys (NCS) and the New Zealand Mental Health Survey, have found the incidence of depression from ages 18 to 32 at a rate of about 18 percent. But they have been roundly criticized by some for their rates being too high. The latest analysis from the Dunedin Study found 41 percent of that age range had experienced clinically significant depression.
As I had hoped, the article’s author did address a very important issue with this brief paragraph -
On the one hand, it could be argued that the diagnostic standards have been set too low if so many people can be considered mentally ill. On the other hand, perhaps these findings argue for more and better mental health care because the disorders are more common than anyone had realized.
During my most recent years teaching development psychology, one slide I presented on late-life sexual changes in males contained this information: While earlier editions of our textbook had stated that the incidence of erectile dysfunction (ED) in 40 year-olds was roughly 7%, the latest edition had the number at close to 40%. For 65+ year old men, the older textbook had the percentage with ED at less than 20. In the newer book the percentage was over 60. The class would discuss explore reasons for the almost unbelievable increase.
Erectile dysfunction may be more common than previously thought. Depression and other mental disorders may be more common than previously thought.
In terms of present thoughts, I am left with a number of them:
> When we learn about something, we can better identify it. With a sharper focus comes the ability to better probe and see what was undifferentiated before.
> When we have words for something, we will use them. Where we lack words, we will over-extend the use of other words. Many disorders fall along a spectrum, but we only have words to describe the two poles.
> With effective treatments comes financial and professional incentives to use those treatments and to make specific diagnoses. When health care professionals can give their patients definite answers, “You have X; here’s a prescription for Y,” the patient walks away with two desired things: Something to call his/her troubling condition, and something to do about it right away.
> In the case of anxiety and depression, if these conditions are so common, can we really call them mental “illness”? Why the human propensity to become mentally ill? On the face of it, it doesn’t seem very adaptive. Yes, some studies have found that a little bit of a bad thing can come with benefits. Mildly depressed individuals actually tend to make more realistic predictions about future developments than do rosy-eyed others; slightly schizophrenic individuals (those with schizotypal personalities) tend to be quite creative . . . .
> Lastly, an observation. It likewise doesn’t seem very adaptive for so many animals in the wild to have fleas and parasites and other physical ailments. (Ailments that we have effective treatments for, and so nearly never suffer from.) Why should human beings be different in a different realm? The brain is a very complex organ that functions in a complex environment: social, emotional, intellectual, etc. Why wouldn’t it be prone to imperfect functioning?
