Angst: Origins of Anxiety and Depression

Psychiatrist Jeffrey Kahn posits—for mental health professional and general public readers—that just five psychiatric syndromes account for modern-day angst: panic anxiety, social anxiety, obsessive compulsive disorder (OCD), atypical depression, and melancholia. His defining theory is that our “primeval ancestors must have evolved these syndromes as instincts with social purposes” (p. viii).

Evolutionary psychiatry certainly has the capacity to explore and explain why humans may be vulnerable to certain mental disorders, and it has evoked rich theorizing over the last decade. But most authors recognize that—like all models and hypotheses—it is unlikely to be all-explanatory. Kahn, more sanguine, draws a very long bow and shaves the nature of mental disorders with his jaunty Occam’s razor. En route to his centerpiece—the description of six “social instincts”—he intriguingly describes evolutionary adaptations and their expressions as synonymous with instincts, effectively merging two somewhat distinct constructs.

Kahn hypothesizes succinct “purposes” underlying his proposed social instincts. Panic anxiety, essentially, keeps us close to home. Social anxiety keeps us in our hierarchical line to maintain peace at home. OCD keeps us on track to maintain the details that allow us to live together safely. Atypical depression keeps us well enough behaved to enable a cooperative society. Melancholic depression keeps us from using up scarce resources when we are no longer useful to the group, and consciousness keeps us responsive to our companions and environment. The inclusion of the high-order domain consciousness as a social instinct is at variance with Kahn’s other five mental disorder candidates.

Because there is no benchmark test for the validity of evolutionary psychiatry, we tend to judge it by its plausibility and the explanatory perspicacity brought to the topic by the discussant, particularly in judging its subtleties, limits, and challenges.

How plausible and how informative is Kahn’s model? His analysis of the evolutionary importance of anxiety disorders (the first three of his social instincts) is consistent with that of most evolutionary theorists, and Kahn imaginatively captures nuances and offers many rich observations from research studies.

Kahn next focuses on atypical depression, in particular a core feature—“rejection sensitivity”—and argues that it has the advantage of helping people follow cultural norms and to avoid confrontation and hostility within the tribe. But those with atypical depression are as hypersensitive to praise as they are to rejection. The consequential emotional dysregulation that marks their observable day-to-day interactions (particularly when they believe they are being rejected or abandoned) does not, at first pass, advance cooperative societal behavior.

Melancholic depression? I can subscribe to the view that some expressions of depression (e.g., “normal” and “reactive” depression) may have evolutionary purpose, providing conservation/withdrawal advantages in encouraging people to withdraw from a competitive situation in which they are failing or as a submissive gesture to avert danger. However, the evolutionary advantages in melancholia are not readily apparent—if, as for schizophrenia, we position it as a medical disease. For example, Nesse (1) wrote that “diseases are not shaped by selection: they have no evolutionary explanation,” and, in relation to schizophrenia, the “causal finger actually points to recent environmental change rather than primarily to genetic etiology” (1, p. 471). Nesse more generally warns about “posing evolutionary explanations without trying to test them against alternatives” (1, p. 471). Kahn appears comfortable in suggesting that in ancient communities, melancholia may have been a “biological method of culling nonessential members from the tribe, thus allowing scarce resources to be shared” (p. 120) or, as he expresses more bluntly, “Take one for the team if you are too old or too ill” (p. 17). Such an interpretation could be criticized factually (e.g., melancholia is not loculated to the frail or elderly) and equally for its rather insensitive jocular tone.

In presenting his ideas, Kahn risks weighting an animated style above substance. His book includes cartoons, song lyrics, quotations, epigrams, witticisms, bon mots aplenty, and certainly enough play on words to put the reader at peril of “pun-ishment.” Granted, the prose is lively, but sentences pirouette across the stage and arabesque into each other. Some examples are: “Alcohol gives beta-dog men the courage to find a mate and gives alpha-dog men the grace to let them, or maybe it just makes the alpha-dog humans fall into a drunken and oblivious stupor (surely they would have had their first dibs on the booze)” (p. 189); and “Antisocial personality is a combination of low agreeableness and low conscientiousness (perhaps counter-intuitive atypical depression, with too little OCD—we’ll get to that later with help from our blues friends, the Who)” (p. 174). Who, Phew! Kahn’s writing style risks leaving the reader suspended from a scaffold of hanging clauses and requesting some noncomic relief.