I just recently finished the book on depression, a difficult issue that, given the tragic death of Robin Williams, is very much alive in the national conscious.
The book’s author, Jonathan Rottenberg (and a former sufferer of deep depression), explores what might be the evolutionary causes of depression – as well as how this knowledge should effect our understanding of the disease.
The Text 
“Seen this way, depression follows our adaption for low mood like a shadow – it’s an inevitable outcome of a natural process.”
Rottenberg’s main thesis is that depression can’t be understood in isolation; rather, the path to understanding depression is to first understand the evolutionary uses of moods. In short, good moods are useful for social bonding and securing reproductive mates, while low moods are useful for increasing alertness and objectively analyzing risks.
This is not to say that depression is adaptively useful – only that low moods are adaptively useful – and the hardwiring that allows for low moods can cause depression as well.
The Text 
“Sadly, what’s good for fitness [low moods] is not necessarily good for happiness.”
This is obvious but hard to remember: we’re wired for survival, not happiness.
The Text 
“The idea that depression results from an inability to disengage from a failing goal is relatively new. Could it be a plausible pathway into depression? … More people in the West – especially the are young – are setting the kind of goals that are likely to become failing goals in the future … today’s youth are much more likely than those of the past to agree with statements such as ‘I will never be satisfied until I get all that I deserve’ … additional evidence for the over commitment theory is that perfectionists are more likely to become depressed than non-perfectionists …”
Raised expectations for the good life – even in the face of objectively higher living standards – may cause depression.
Personally, I try to keep the phrase “nobody promised us anything” close at all times.
The Text 
“People who value happiness are less likely to achieve their goal of feeling happy…. Ultimately, the strong cultural imperative toward being happy bumps us up against a wall: our mood systems is not configured to deliver an end state of durable euphoria.”
This, I suppose, is the ultimate paradox of happiness.
Depression is a very tragic disease. For me, hearing theories about its evolutionary roots helps me make some sense of depression, even if these theories are tentative.
I would have liked to have seen more evidence for the case that we’re seeing a depression epidemic rather than just an increase in reporting.
I’m open to the idea that increased expectations and a narrow focus on the pursuit of happiness increase the probability of depression, but it’s somewhat hard for me to distinguish causation and correlation here.
But, ultimately, the books thesis is worth wrestling with: is the risk of depression, which stems from our evolutionary adaption of low moods, increasing due to our modern environment and culture?
Most of all, I hope that continued research will help all those who suffer from depression. No one deserves its afflictions.