The Depths – The Evolutionary origins of the depression epidemic

by Jonathan Rottenberg

Publisher: Basic Books

ISBN 978-0-465-02221-2

I took up this book in a bid to understand what a patient means when he says ‘you cannot understand what I’m going through’, and to better understand depression. Coming from a person who himself has been suffering from it and has now recovered, I hoped to get some valuable insights about this mental state. The author brings into light the monstrosity of his own situation, of how, despite how hard he tried, he just couldn’t get better. ‘I certainly wanted to believe that improvement was possible. 18 months into my depression, I walked on Woodlawn Avenue, on the outskirts of Baltimore, a wilful act to keep moving. Was this walk better than the last one, or the one before that, or the couple hundred walks of desperation before that? Even though I wanted to believe it was, it did not seem any better. Traffic, and the whole world, buzzed by me. I still could not think straight. I felt completely obliterated as a human being. My thoughts were desperate as usual. When I noticed other people, I wondered what it was like to be alive. They did not know, could not know, how I felt inside. My shell still passed for normal. I felt like I should scream for help, someone should help, but I knew that the time for screaming at passed. Best to just keep on walking, walking dead, one of the few things I could still do. So I kept on walking. Optimism spent, still I couldn’t accept an unacceptable fate.

Rather than straightaway talking about what depression is, the author sheds light on its roots. His main point of contention is “a diagnosis of depression on its own does not explain the ‘why’, offers no interpretation of what might be wrong and - as important - what needs to change for all to be set right.” Clinically, a person is diagnosed from depression if he exhibits signs like despondency, extreme lethargy, inability to concentrate, insomnia and periodic thoughts of death, suicide and guilt. But people ascribe this ‘why’ to a deficiency – deficiency “in brain (says the psychiatric), thoughts according to the cognitive therapist, childhood (psychoanalyst), soul or relationships with God (priest or a rabbi) or relation with a significant other (varietal or family therapist).” Because of this perception of deficiency, the patient suffers on two fronts - one is depression itself, the feeling of being deficient which soon starts to raise its head in other walks of like too, and other is the fact that society reacts to it differently with “what is wrong” with them. Consequently, “the lacerating pain of depression remains uncontrollably private”.

He argues that the effectiveness of aspirin does not prove that headaches are caused by lack of aspirin, similarly the success of cognitive therapy doesn’t mean that depression is caused by cognitive defects. Medicine is partially effective, if effective at all, and so are all other therapies so far, not to mention it is addictive (which he does not mention in the entire book). If something works, it is always a fluke and no one knows why. What medicines try to do is reversing the effects, like suppressing the secretion of cortisol which could have become unregulated due to onset of depression and hence worsening mood, but it does not stop depression, only its symptoms.

There is another, a totally inverted view of what depression is, which proposes that if for once we stop treating depression as a defect, that something is broken and needs to be fixed, and think of it as something that is meant to do good (but has gone awry), we might be able to circumvent the impasse that clinical treatment hasn’t been able to get around. This is his yardstick throughout the book. One sufferer said "It sucks, but there's value in it", just as Shakespeare wrote for Hamlet ‘Though this be madness, yet there is method in’t.’ It is called ‘The Mood Science’.

Rottenberg traces the origins of depression in our mood system and how it has evolved over time with our bodies. Even clinical science agrees that Depression arises from mood, its defining feature is ‘persistent low mood’. “Our bodies are a collection of adaptations, evolutionary legacies that have helped us survive and reproduce in the face of uncertainty and risk." But evolution and adaptation need not be perfect or for good. It is like a patchwork, an ongoing bug-fixing. Flawed designs, if they promote survival and reproduction, are more than good enough even when they are flawed. The arguments tend to make evolutionary sense – he compares the trade-offs in evolution to a cost-benefit model. For everything that adapted in us, there is a certain benefit to it, and also, certain costs. As long as the benefits outweigh the costs, evolution does not mind. To humans, for instance bi-pedal from four legs was an adaptation to increase and improve hunting but it also means increased stress on the back and more injuries to the spinal column.

He also points out the fragility of these adaptations – “They may play out only if an animal is in its typical environment. In the dense primeval forest, deer that froze at the first sniff of a wolf were (and are) less likely to be seen by a predator skilled at detecting movements. Deer evolved like that, but a deer frozen in the headlights shows that a generally useful behaviour is not useful in all environments. The advent of motorcar increased the costs associated with deer-freezing behaviour.”

Similarly, “humans have a tendency to select and eat calorically dense foods when available. Historically, it had more benefits than cost because the spectre of famine has loomed for nearly all of evolutionary time. The costs associated with efficient storage of food energy and a preference for rich foodstuffs becomes apparent in modern environments where food is abundant and drive-through Mc D's are ubiquitous; leading to an obesity epidemic and related conditions.”

Technological leaps have made lifestyle changes so fast that evolution has barely kept up, instead, it could have taken them as threats. This is one precursor to why depression epidemic has seen a prominent rise, particularly in the last quarter of 20th century, despite all the improvements in medicine, general health and life expectancy.

Similar cost-benefit calculus applies to psychological adaptation too, and that we have good mood as well as bad mood is because both have advantages (but also costs). Thus, there doesn’t seem to be a thing that is totally good and beneficial at the same time. Fantasizing about a world without low mood is a vain exercise. “One way to appreciate why these states have enduring value into and ponder what would happen if we had no capacity for them. Just as animals with no capacity for anxiety were gobbled up by predators long ago, without the capacity for sadness, we and other animals would probably commit rash acts and repeat costly mistakes.” We wouldn't learn. This reminds me of Jim Carrey's stand-up comedy of having that inner voice say 'Ac Ac Aa, you don't want to do this".

One may think of how can a thing as terrible as depression or bad mood ever be helpful, or beneficial. "Good moods broaden attention and make people inclined to seek out information and novelty… The positive moods are not only assign or read out that we are on the right track and moving towards evolutionary goals which are favoured, they also feed forward into our future behaviour."Anxious mood narrows the focus of attention to threats", perhaps that is why, as research suggests, people in sombre or low mood tend to make more rational and better decisions, since they are being more realistic. Our mood system is built for maximizing rewards. If we set a goal and observe a minor obstacle, we double our efforts'. But if the mood system knows that the obstacle is insurmountable, it balks and de-escalates the urgency. Adrenaline and blood flow spikes stop and also escalates low mood which if kept unchecked, might spiral down to deep depression.

Since the study of historical patterns and causes of depression in humans is not possible, because we evolved, he turns to the animal kingdom for his answers where past experiments with rodents, canines and in one instance a controlled starvation experiment on a group of volunteer researchers revealed insights about how ‘shallow depression’ is often the precursor to a long ‘deep depression’ and what factors may pull the triggers. But in every case, it comes as the body’s natural response to survive, to lie low, while the storm lasts. Rending social bonds can trigger it, isolation, defeat etc. are all possible culprits. “The initial stage is of denial, protest and agitation; then we hunker down and conserve life spirit, just like animals do”.

The author notes that 'Homo sapiens' has the dubious distinction of being a species that can become depressed without a major environmental insult. He states that "a chimpanzee is capable of feeling bad, but only a human being can feel bad about feeling bad." He explains, "A hallmark human response to low mood is to try to explain it-as we do with moods generally.... The basic idea is, ‘If I understand why I feel bad, I will know how to fix it’. But our view of the environment, because of our human assets like ‘advanced language, the ability to be self-aware, and participation in a rich shared culture’ become liabilities which then makes depression worst as we analyse more carefully.”

He is quite right on in his assessment when he tells that "The human meaning-making machine is so good at what it does that it can generate interminable interpretations. When persistent thinking get stuck, it does not arrive at a stable theory of the problem, does not solve it, and cannot come to terms with it. Far from engaging in active problem solving, a person may simply perseverate on the fact of the problem for months on end. When the meaning-making machine gets caught in this way, its analysis turns inwards, drifting its focus from a problematic environment to a problematic self.“ This could lead to depression.

This meaning-making machine is not easy to downshift and that is why ‘the most useless pieces of well-meaning advice to give someone in midst of a deep depression are "Snap out of it" and "stop thinking about it."’

As one patient related, "When in bed, I zone out and it is either just blankness, a nothingness that runs through my head or one phrase just keeps repeating over and over which is " What am I going to do now? I never get a response or solution to the question.” He explains that they "can’t bring themselves to get out of bed. Almost any other activity or task becomes a painful ordeal, even activities as simple as taking a shower or getting dressed."

Despite of depression being a shutdown measure to preserve and sustain, it does extract costs which are not beneficial for fitness. For example, it carries a risk of high blood pressure and risk for heart attacks. But he gives hope. “It is important to remember that although evolution has powerfully shaped our capacities for mood, we’re not its prisoners. Even with a powerful evolutionary directive to become depressed, we can retain a margin of control to shape its course.

He lays impetus on the role of self will power to combat it, like “Sara says she knows that sunlight and exercise are ‘free antidepressants’, a statement that is borne out unmoved research. But she doesn’t act on this knowledge. Instead, she often pads around in her pyjamas until mid-afternoon. She persists in following a routine she knows to be mood depleting.

The author does not visibly give any conclusive answer to how to rid oneself of it, but hints at various causes underpinning the worsening of a bad mood. Further, he talks of what he went through and how the journey back is very slow, and usually follows the same path that led one down the well. He proposes that by understanding how depression works, and by the wisdom of others who have bravely battled it and succeeded, people in need of help will find the will and motivation to beat theirs and break the cycle.

Positive outlook, exercise, having a life purpose, and having achievable goals, above all, letting go of unachievable goals, family, friends and a healthy social circle, a hobby a distraction are few of the things he proposes as remedial measure, along with medications and therapy.

His viewpoint is largely positive, and this he claims as an effect of recovery. Recovered people tend to look at life with a better perspective than them before the unfortunate episode, and even better than most, non-depressed people in the world. He reasons that it is difficult to single out one cause, likewise it is difficult to single out one method out of all the remedial measures taken. He urges the scientific community to indulge in a healthy and responsible dialogue, rather than being driven by political and egotistical gains. Above all, he urges people to stop looking at depression as a defect, but as an evolutionary counter measure to increase longevity and fitness. Let us say, it is a test of mettle that evolution has poised yet again, to see who survives in this race of survival of the fittest.

About the book, I don’t think it is just for the people who are suffering from depression. Or rather, as from what I’ve experienced so far, everybody goes through little periods of shallow depression throughout their lifetimes and anybody could relate to it. I for one, could draw quite a few parallels in what I’ve experienced, or read in non-psychological books and in other people as well. It is worth a read.

I'll add my notes in the discussions section shortly where I discuss what and how some things work with me.