The mental and sometimes physical experience of pain embedded in depression drives patients, their loved ones, and many treatment providers to seek a uniform understanding of depression’s causes. I think it’s misguided to provide one. There is no unified theory of depression, and there may never be. But the journey towards understanding your own depression is often the more important half of the journey to recovery because it leads to greater insights and understanding of yourself and revives the ability to create meaning and actively write your own story. Below I’ve highlighted some of the models that I find useful in understanding what causes and perpetuates depression. In the future I will use these perspectives as a jumping off point for identifying treatment strategies and developing plans for recovery.
Emotional Blockage
People are meant to experience the full range of basic emotions frequently and fully. Think of it as exercise for your limbic system. There's some debate over what constitutes the emotional palette but a good place to start is these four: sadness, enjoyment, anger, and fear (or let's say worry, if you're toxically masculine and "allergic to fear"). Some might add surprise and disgust to this list, but I usually focus on the Big Four. There are exceptions but I find that most people who, for whatever reason, either don't experience one of these emotions or devote too much mental energy to avoiding it end up in some flavor of psychological trouble. Sometimes that trouble is addiction or other bad habits but very often it's depression. That emotional flatness and emptiness that's often associated with depression? Often that's the result of a blockage, like a river that's been dammed up.
And this might sound strange but I think that the emotion that goes "missing" most often in depression is actually sadness. I know that might sound counter-intuitive but try this mental exercise. Think about someone you love dying. Maybe it's your fault, but nobody knows that. And now imagine that you're unable to feel sad or cry about it, think about how that would feel in your body. Now imagine that after months you were able to talk to someone and unburden your guilt about the death and finally cry and be filled with that sadness and achieve closure. That kind of cleansing emotional intensity is called "catharsis" by the way. I hope this example helps you understand how the lack of sadness can lead to depression and how that might feel. But why does it happen?
I believe the number one culprit is the fear of sadness. This is especially common in people who experience chronic clinical depression. Sadness can be a core experience of depression. And people who have experienced severe clinical depression are almost always traumatized by it on some level. Or at the very least they're sick and tired of feeling sad, they're over it. So they do their best to avoid feeling sad. There are many strategies people use. One is distraction: when a sad thought enters the mind, think of something else. Look at your phone. Do some work. Daydream. Look at your phone. Look at your phone. A more advanced tactic is called displacement, transforming one emotion into another. Usually if the initial or base emotion is something perceived as unpleasant then it's easier if the new emotion is a little unpleasant too. Transforming sadness into anger generally just requires finding something or someone to blame. And guess what? You can even blame yourself! But fear is also an easy option if your whole motivation for avoiding sadness is because you're afraid of it. Just lean into that fear and make some catastrophic stories up about it and soon enough you can make those stories true as the paralysis sets in and the world darkens around you. But maybe the most direct and effective way to avoid sadness, for those who are capable, is dissociation. That emptiness, that feeling of alienation from yourself, that sense of distance and coldness emitted by the world, that numbness and strange heaviness in the body, they have a flavor that can distort sadness beyond recognition. And usually dissociation is a skill learned by those who experience trauma, isolation, and depression in childhood.
Don't get me wrong, the avoidance of anger can also be a major factor in depression. You ever heard the term "wallowing in sadness"? Well there's nothing wrong with throwing on the Portishead or Patsy and just letting the vibes take over now and then. Again, feeling sadness sometimes is very healthy! But when sadness becomes your go-to safe and comfortable emotion that can set you up for problems. For many people anger is absolutely the most horrible emotion to experience. For one thing it can sometimes feel out-of-control or lead to serious consequences like hurting someone or losing a relationship. And this can lead to a fear of anger. Anger is also a taboo in many families and people are taught that they are weak or selfish or evil even for feeling it, and certainly for expressing it. And sometimes people learn to hate anger because of their horrible experiences with other people's cruel and punitive anger. When anger is misplaced into sadness long enough then people usually end up vacillating between extremes of guilt and self-blame on the one hand and self-pity and feelings of victimhood on the other. Because remember, anger is closely tied to blame. And when we lose the ability to assign and respond to blame in a conscious and empowered way, we start to feel powerless, we lose agency. Sounds pretty depressing right?
Learned Helplessness
Animals can't fill out surveys. They can't self-report. So it can be hard to measure their emotions, much less somewhat more abstract ideas like depression. Because antidepressants and other medicines generally have to be tested for safety first on animals, this means scientists had to figure out the best ways to understand and measure animal depression, preferably through something that can be observed in a non-invasive way like behavior. And so they developed the Learned Helplessness model. Basically, many animals can be trained that in certain situations, nothing they do matters. They will either be unable to get something they want or unable to avoid something they don't want. They will give up. And sometimes it stops there: a lesson learned in a certain situation. They stopped banging their head against the wall. Seems like a sign of intelligence, right? But sometimes the animal will start to generalize that experience to other situations. They will start to give up in a more globalized way. They will assume that there is nothing they can do to achieve their goal. They have learned helplessness. And scientists have found that often when you give an animal in this state an antidepressant, it will reverse this state. They will start treading water, or running through mazes, or pushing buttons again. They will take action to seek reward or avoid consequence. They're cured!
As a therapist, when I'm assessing depression I focus quite a bit on concepts like powerlessness, hopelessness, and helplessness. I also focus on the broader concept of negative thinking and beliefs about the power of choice and action to achieve results. And what I'm mostly looking for is learned helplessness. The world is not a perfect laboratory and people develop learned helplessness through a complex interaction between their temperament, their upbringing, and their situation. Some people seem totally immune to “helpless” thinking and maintain a (naive?) hope no matter the odds. They just won't quit. If anyone has an immunity to depression it may be these folks. But most of us are much more responsive to rewards and consequences in our environment. And that can be highly adaptive until we find ourselves in a situation where the reward structure strains the limits of our belief system. Then suddenly we can feel very trapped and believe that we lack the ability to escape. This can lead to either a freakout or a collapse or some combination of the two, and these reactions often reinforce the barriers in our situation.
When learned helplessness is at the core of depression, usually actions need to be taken to alleviate the sense of isolation and stuckness. The problem is that learned helplessness reinforces the belief that these actions don't matter or are too hard. And to be honest some of the more organic symptoms of depression like fatigue, poor focus, and mental slowing can really interfere with planning and action. Also one major feature of depression called anhedonia can make it difficult to perceive the emotional rewards that normally come from actions like pursuing our interests. Usually I find that someone who is even in a therapy session has already started on their journey of recovery from learned helplessness because they are seeking help at all. When there is nobody to interrogate or push back against our negative beliefs it is easy for them to self-reinforce. Those negative beliefs start to feel like a feature of the environment, a part of the experimental design, when really they are just in our head.
Fallout From Chronic Stress
Cortisol has become a popular punching bag recently and for good reason, although I think we've gone a bit too far. After all if it wasn't for cortisol I doubt half of us would ever get out of bed in the morning. But this stress hormone definitely has a dark side, along with it's sexy big brother adrenaline. Having too much chronic stress for too long is a very common contributor to depression, along with plenty of other health consequences like heart disease, obesity, and even diabetes. Biologists are still trying to figure out all the mechanics behind this but it looks like our immune system plays a major role in mediating this cascade.
Unlike "situational depression" where some major negative life change or event results fairly quickly in a depressed state, the relationship between chronic stress and depression can be a bit harder to understand in terms of timing. This is one reason why it can take so long for people to figure out how to manage their depression long term. Sometimes stress builds over time, maybe years, until depression starts at a time that might seem arbitrary. There's almost always some challenge present in life and people love to find cause-and-effect patterns so it's rarely hard to find a scapegoat that might obscure the real cause. For others, the timing of depression can follow the "finals effect". For those of you who went to college or grad school, or had a job that involved occasionally turning in massive assignments or presentations: did you ever notice how just after the big project or final exam you would often get sick? It can be very inconvenient because often you might have a big party or vacation planned but instead you spend several days nursing a cold or ear infection. Some people's bodies have a way of getting us through a challenge then immediately powering down when the challenge (and accompanying adrenaline) is gone. Think about how a marathoner might collapse onto the ground after a big race. When we push our body past what's healthy or comfortable, the compensatory resting state can also be extreme or unwanted.
For people suffering from certain chronic mental or physical health conditions I sometimes find the concept of "adrenaline addiction" to be useful. On the one hand, it's absolutely true that our attitude towards stress can powerfully change it's consequences... people who have a positive view of stressors (perhaps viewing them as exciting challenges to overcome) can tolerate stress better. But there are limits to this strategy. Think of it as the psychological law of thermodynamics: what goes up must come down. And some people lean into stress for other reasons, like maybe it feels like the only way to provide the energy, motivation, and focus to stay in motion and get things done. Adrenaline can powerfully provide these things, at a price. Some people use "workaholism" as a distraction from emotions, a way to avoid conflict, or strategy to avoid other unwanted emotions (sound familiar?).
Adaptive Reaction
Often a prominent feature of early treatment is to encourage the client to label and understand their depression (or other mental illness) as something that is separate from them, like some invader or parasite that can be battled, boxed in, and eventually dispelled. This can be extremely helpful for some people and I think that the exercise always has value as a tool for introspection and building insight. But sometimes it fails spectacularly, for a variety of reasons. When this exercise fails one area I like to gently explore with the client is whether they see any advantages to their depression, or at least to the timing of it. This can be a difficult line of questioning for some people because it can reveal unwanted insight. But healing without this layer of self-knowledge can be like fighting with a blindfold on.
The field of evolutionary biology is a long way from fully explaining the causes of mental illness. But speculation into the possible adaptive advantages of of depression can be a helpful starting point if your goal is to reframe your depressive episode more positively. Perhaps depressive traits helped to put us into a resting state, a kind of quasi-hibernation, when food was seasonally scarce in winter or the dry season. Maybe depressive traits encouraged people to act less impulsively, to withdraw from action and think more deeply and realistically about problems, to "measure twice and cut once". Maybe depressive traits helped us identify situations in which a less aggressive presentation and attitude would keep us safe, to know when to quit when we were on the wrong end of a dominance hierarchy. I say depressive traits because I believe that full blown depressive episodes are often an overexpression of traits that in other contexts are clearly helpful. But to restate the above in more simple language...
Depression can help us identify the need for rest and healing. Depression can make our thinking more realistic. Depression can give us space to take a step back and fully explore a problem instead of acting impulsively. Depression can protect us from conflict. Depression can signal to the people around us that we are hurt and in need of care. Depression can help us identify and acknowledge our own weaknesses that we don't want to see. Depression can put you in check. No matter how barbaric it's consequences: depression is an opportunity for growth, whether we feel comfortable seeing it that way or not. Sometimes when you have wandered too far away from your authentic self, depression is the one voice that you cannot ignore that is calling you home.
I absolutely know that this way of thinking isn't for everyone. But if you don't understand the potential treatment advantage of positively reframing depression, you do not understand the illness.
Misplaced Coping
There's a proper place in the discussion for almost every familiar concept, but generally I think that the notion of "self sabotage" has been overused in our culture. Most of us believe that we're doing our best most of the time. And for most people, even most people who are undiagnosed and seem "healthy", doing our best means spending quite a bit of time and energy coping with unwanted thoughts, feelings, sensations, and other difficult mental phenomena. Some people are lucky that early in life they develop a toolbox of extremely effective and appropriate coping skills that serve them well throughout their lives, probably with occasional readjustment. But that same toolbox doesn't work for everyone. Sometimes a person has great tools but a situation will arise in their life that requires a tool they don't happen to have and that will be their first experience of full blown mental illness. This can be one of the easiest kinds of case to treat, so easy in fact that very often these people find ways to heal themselves without professional help. What I see more often in my office is people who are overusing tools that served them well in other situations but are now doing them damage. They are hammering the same nail until the board starts to crack. This is what I mean by misplaced coping.
Coping skills can take many forms. The easiest to understand are cognitive and behavioral. Many of the cognitive ones get labelled by CBT therapists as cognitive distortions. You can find long lists of cognitive distortions online but one of the most applicable to depression is negative-biased mental filtering. Negative-biased mental filtering is essentially when you tend to abandon positive thoughts and examine negative thoughts more closely. When your mood and outlook is generally positive this can be very helpful. Think about when you're editing a long email. If you read a sentence that's good and doesn't need changes then once you identify that the best thing to do is move on quickly to the next sentence. But when you find a mistake or poor phrasing, that is something that warrants attention and further thought. So efficient people tend to do a ton of this kind of mental filtering. Another way of framing this trait is saying you have a "critical eye". It's extremely valuable in almost every profession and when it's rewarded it can become a default way of operating. But when your mood and outlook become negative the over-exercise of negative-biased mental filtering can pave the road to depression. It isn't helpful to carefully examine and investigate every self-critical thought when you are constantly flooded with them. But it's the automatic dismissal of positive thoughts that can make this kind of mental filtering so destructive.
Behaviors are more concrete and easier to understand but sometimes it can be harder to identify when they have become counter-productive. Maybe you love going to the gym at night. You aren't a morning person and the idea of an AM workout sounds like a war crime. You love how quiet and peaceful the gym is at night and it helps you get in the zone. Something changes and you become depressed. You don't enjoy your workouts as much but they're the only thing you look forward to because the rest of your life is much worse, the gym is your comfort zone. You feel restless all night, your mind going non-stop searching for faults and tearing you apart. After just a few hours of sleep you peel yourself out of bed feeling leaden and drained, walking through your workday like a zombie. Only in late afternoon do you start to perk up, looking forward to dinner and the gym. But as soon as you leave the gym your mind starts to attack you and the cycle repeats. Many people assessing this situation wouldn't give a second thought to the evening workouts as a maladaptive coping skill. After all, exercise is well known as a great treatment for depression and why would you disrupt the one thing that a depressed person seems to enjoy? But from the way I framed this case study I bet you can understand how it's possible that the gym routine described here might be feeding a bad cycle. Sometimes something shifts and a behavior that was once a centerpiece of our mental wellness can reinforce patterns that lead to depression.
I have only scratched the surface here in terms of causal theories for depression and I may dive into others in the future, but aside from medical and biological models the ideas above are the most important for framing my own treatment approach. If you care to comment I would love to hear from you about a way of understanding your depression or other mental illness that was especially useful. Take care.