Rebecca Blood points to this report of a new study suggesting that humiliation is more important than pure loss in promoting depression. The writer, Ellen Barry, gets one at least one thing badly wrong in her article. She says that the study “calls into question assumptions about depression that date to Sigmund Freud”, implying that Freud founded his theory of depression on loss. But his seminal 1917 essay on the subject, Mourning and Melancholia, thinks along much more sophisticated lines asking what the difference between an uncomplicated loss that leads to resolvable grief and one that leads to an involutional depression might be. Althoguh this is an oversimplification, Freud said that if the person’s attachment to the lost object was ambivalent, e.g. tinged with anger, the anger will be turned inward and mourning gives way to melancholia.
Now we have the Kendler study, making a big deal of the fact that it is humiliating losses, rather than just any ol’ losses, that predispose to depression. There’s a problem with this however. Does Kendler distinguish certain losses which are intrinsically humiliating in social status terms from those where it is the sufferer’s low self-esteem and vulnerability to depression which predispose to feeling humiliated? In other words, does being humiliated cause depression or does depression cause one to feel humiliated? Although Kendler tries to isolate the environmental from the constitutional factors by comparing identical twins with disparate experiences of depression, he may not have explained much.
One of the reasons the report interested Rebecca is Kendler’s nod to the evolutionary significance of depression. “How on earth does a tendency for acute and chronic hopelessness in any way benefit human survival?” she has long wondered. Evolutionary psychopathology is one of the intellectually stimulating venues in psychiatry today, one of the fun places to be, since it involves so much pure speculation. It has the thrill of controversy around it because it is firmly predicated on the materialist proposition, with which some are not very comfortable and about which I write about quite abit here, that complex behavioral patterns are brain-based and have biological and genetic roots. Evolutionary psychology has had to overcome the intellectual distaste that was aroused throughout academia several decades ago by the arguments of Richard Herrnstein and Arthur Jensen (among others) about the genetic roots of IQ, which were seen as being used to further a racist agenda. Perhaps because genetic studies are more sophisticated nowadays and proponents are more careful about which complex intellectual or behavioral traits they claim have genetic bases, evolutionary psychology is enjoying a resurgence. Even a socially progressive mental health professional leery of the insidious uses to which such thinking can be put can be intrigued and captivated by some of its speculations and implications.
That being said, one of the most appealing evolutionary theories of depression — only one among several — is the one consistent with Kendler’s findings and described in the article, that depression evolved in the proto-human pack economy as a way to reduce resource utilization and ambitions by one with lower social status, as one might have after a humiliating loss.
By the way, Rebecca, for a maladaptive trait to survive evolutionarily, it does not necessarily have to be beneficial to human survival, as your question suggests. Although this theory of depression does suggest that it is beneficial, all that is necessary for a trait to survive is that it not have an adverse effect on reproductive fitness. For example, a trait that expresses itself after the reproductive years will be neutral with regard to survival and not selected against. Or, a partial expression of the trait may confer an advantage, while those unlucky enough to get the full genetic load may suffer — too much of a good thing, if you will. This is discussed, for example, with respect to psychotic disorders such as schizophrenia or manic depressive (bipolar) illness. Could, for example, lesser expression of the relevant genes inspire quirky visionary originality of thought and creative energy, while the full flowering of the tendencies spins one out of control? (In modern society, it is certainly true that psychotic disorders, which have their most common onset in young adulthood, confer a reproductive disadvantage, but are artists or visionaries advantaged? There was a study I wrote abut here several weeks ago which peripherally bears on that, suggesting that marriage is the kiss of death to creative output…) Think, for example, of the difference between James Joyce’s fractured language and the fractured thought of his schizophrenic daughter Lucia (a patient of Jung’s), which one commentator likened to the difference betwen swimming in the river and drowning in it. A more prosaic example, although not from psychiatry, is sickle cell anemia. While having a double dose of the gene gives you the devastating syndrome, a single ‘hit’ (which gives you “sickle trait”) apparently confers some resistance to malaria, which is endemic in the regions where the sickle cell mutation arose.
