The Corpus Callosum

IN the fall of 2005, psychiatrist J. Anderson Thomson Jr. was treating an 18-year-old college freshman whom he describes as "intensely depressed, feeling suicidal and doing self-cutting."

A few years before, Thomson says, he would have interpreted her depression as anger turned inward. But instead he decided that her symptoms might be a way of signaling her unhappiness to people close to her.

He discovered that his client's parents had pressured her to attend the university and major in science, even though her real interest lay in the arts. In the course of therapy, he helped her become more assertive about her goals. When she transferred to another school and changed majors, he says, her depression lifted...

So I'm skeptical.  With respect to this particular article, I understand why the author led with a specific case.  It adds human interest to the story, perhaps drawing the reading into reading the rest of the article.  But from a medical education standpoint, it is potentially misleading.  Individual cases can be highly misleading.  As my professors used to say (and presumable still do say), never draw a general conclusion from a specific case.

When I say I am skeptical, though, I should be clear.  I do believe that evolution shapes psychology, I do believe that the subject is amenable to empirical study, and I do think that there might someday be some practical application.  But I also think the field is very early in development, and I do wonder if it has any current clincial application. 

Speaking of my professors, one of them was quoted in the article:

...Evolutionary psychology sees the mind as a set of evolved mechanisms, or adaptations, that have promoted survival and reproduction. Evolutionary psychopathology — abnormal psychology through an evolutionary lens — looks at what has gone wrong.

The discipline is so new that "some people would say it hasn't started yet," jokes Randolph M. Nesse, a professor of psychiatry at the University of Michigan, and one of its pioneers. No one paradigm has won universal acceptance. Evolution-based therapies rely on an eclectic mix of techniques, and their effectiveness is still being tested...

I must say that is sensible.  One of the pioneers in the field acknowledges that it is in its early stage, that the clinical utility is uncertain.  So what is the real story?  Dr. Nesse has kindly provided some video lectures on his own site, here: Lectures by Randolph Nesse Available on the Web.  

The way I see the subject is this: knowledge of the principles of evolution is crucial to the understanding of medicine is general, and psychiatry in particular.  Evolutionary theory is rich with models for the understanding of change over time.  At this time, we are not able to specifically map the evolution of behavioral or cognitive traits, in terms of genes or the regulation of transcription.  (With a few exceptions, such as Huntington disease.)  Even so, the mental models one uses to understand evolution are models that can be adapted to understand other topics.  This can be used to provide a different perspective on the complex field of human psychology.  Often, different perspectives are helpful.

I find it interesting to think of how psychiatry may be coming around in a circle.  Historians of psychiatry are inclined to think about the relationship between Sigmund Freud's hobby -- archeology -- and how the study of the past became a metaphor for his psychoanalytic technique.  This is nicely illustrated on a site devoted to the Freud Museum:

The Study is also filled with antiquities from ancient Greece, Rome, Egypt and the Orient. Freud visited many archaeological sites (though not Egypt) but most of the collection was acquired from dealers in Vienna. He confessed that his passion for collecting was second in intensity only to his addiction to cigars. Yet the importance of the collection is also evident in Freud's use of archaeology as a metaphor for psychoanalysis. One example of this is Freud's explanation to a patient that conscious material 'wears away' while what is unconscious is relatively unchanging: "I illustrated my remarks by pointing to the antique objects about my room. They were, in fact, I said, only objects found in a tomb, and their burial had been their preservation."

Archeology and human evolution are different topics, but there are important similarities.  Both seek to understand how the past led us to where we are today.  Psychology, particularly psychodynamic psychology, shares this trait.  

The earliest psychiatrists focused on the past as a way of understanding the present.  Now, we find that the most modern psychiatrists are doing the same. But instead of focusing on the history of the individual, they are looking at the history of the species.  Instead of looking at how the experiences of the individual shaped the thoughts and behaviors of that individual, they are looking at how the experience of the species shaped the cognitive and behavioral processes observed in the modern population.

One could speculate about what it means: the field has come full circle.  I don't believe it has any metaphysical meaning, but it does illustrate the main point of this post: concepts, or mental models, are versatile.  A model that helps us understand one thing, might very well help us understand something else.  The more models you have ingrained in your mind, and the more detailed and accurate those models are, the more likely you are to be able to extend your knowledge and understanding.  When it comes to medicine, a thorough understanding of evolution is as versatile as it is indispensable.  Even if it still needs a bit of refinement.