Is There a Root Cause for Depression?

Is there a root cause for depression? – graphic of a head with tree growing inside

I was recently reading an article that argued that to fully treat depression, one must do the inner work to get to the root cause. That didn’t sit particularly well with me, so I thought I’d write about whether there’s even such a thing as a root cause for depression.

The problem with reductionism

I’m of the perspective that mental illness is complex, and the causes are just as complex. If we get too reductionistic, we can lose sight of what else could be in the picture.

By reductionistic, I mean simplifying the root cause down to being 100% attributable to one thing. That could go in a medical/biological direction, or it could go in a situational/trauma direction. I don’t see either as particularly helpful.

I conceptualize the causes of depression on a continuum from fully biological to fully situational. A few people are at either extreme, but a lot of people are somewhere in the middle. I like the diathesis-stress model, which looks at the interaction between genetic and psychological factors to produce illness.

Diathesis-stress model of mental illness


We know that there’s often a genetic element to mental illness, but we know very little about how that actually works. One way of examining this is twin studies. Monozygotic twins come from a single egg and sperm, and so have identical DNA. Dizygotic twins come from 2 separate egg/sperm pairs, so they do not share the same DNA.

The concordance rate (probability of sharing a specific trait) for major depressive disorder in monozygotic twins is almost double that for dizygotic twins. For schizophrenia, the concordance rate is even higher, suggesting an even stronger genetic link.

In my own family, there was one great-uncle (possibly two) on my dad’s side with schizophrenia. That’s it. There’s no other known mental illness in the family.

Childhood trauma

Childhood trauma may be a contributing factor for some people’s depression, and there’s some really interesting data from the adverse childhood experiences (ACEs) research on this. Stress and trauma, particularly in childhood, can cause “epigenetic” changes. We have the genes we’re born with, but it’s more complicated than that. Genes code for various proteins, but when/how our bodies actually make those proteins falls within the field of epigenetics.

Interactions with our environment are a major factor, but there is still so much more to learn in this field. There is even some research suggesting that epigenetic changes can even be passed down to offspring. It’s a really interesting area that I suspect will be a source of some major discoveries as science moves forward.

For me, there was no childhood trauma. Yes, I had the “normal” challenging experiences that people are likely to have, but I wasn’t abused, neglected, or bullied. I was lucky enough to have parents that were caring, affectionate, and supportive. We were financially secure enough that I had opportunities that might not have been available to others. I did well in school, and while I wasn’t popular, I was comfortable in my circle of close friends. The really challenging stuff that’s happened in my life, including bullying, came after I got sick, not before.

Psychosocial factors

Substance use could potentially be an issue for some people, but I don’t think it was for me. Yes, I drank a lot of alcohol in my late teens and early 20’s; however, there were no apparent negative consequences other than the odd hangover. I had no problems stopping drinking when I moved on to the next stage of my life.

I was not someone who was prone to low moods. I’ve always been emotionally sensitive, but overall I was a happy, optimistic person with good self-esteem, a solid core group of good friends, and a career that I found very meaningful. I didn’t have my first episode of depression until age 27, although, looking back, there may have been an earlier hint of things to come.

When I was 15, I experienced 2-3 months of unexplained physical symptoms, including weakness and fatigue severe enough that I could barely get in and out of bed. Various tests were done, but no physical cause was identified. From what I recall, my mood was mostly numb, and I didn’t feel depressed. Still, there’s a definite physical resemblance to depressive psychomotor retardation (slowing of movement and thoughts).

My non-history & the pattern of my illness

When I had my first episode at 27, it came on over the space of maybe 4 months, triggered by situational stress that was not proportionate to how sick I got. My ex-boyfriend and I had remained very close friends after I’d broken up with him, but then he started dating someone and all of a sudden my best friend didn’t want to be in my life anymore. It was difficult, but I had sufficient coping skills that I would’ve expected that I could handle it.

I had two suicide attempts within a couple of months, then ended up in hospital for 2 months, psychotic and continuing to try to take my own life. Later that year, I went off meds because I felt they weren’t working, but I ended up achieving full remission despite that. That was only temporary, and the illness has become far more chronic and treatment-resistant.

From the beginning, my pattern of illness has been most consistent with the melancholic subtype of depression, which appears to have stronger biological roots than other forms of depression. I’ve responded best to biological treatment, particularly ECT.

Where the heck did this come from? Is there a root cause? Why did I get depressed? I doubt I’ll ever know the answer. In the end, I suppose it doesn’t really matter all that much; still, I wish I knew more about this beast that has intruded into my life. How did it sneak up out of nowhere, and why did it pick me? Is it the ghost of that distant great-uncle’s genes swooping in to haunt me but sparing everyone else in the family?

Not everyone is just one way

Whether it’s saying that everyone only needs meds, or everyone needs to do a psychotherapeutic deep dive to get at their deepest inner wounds, saying that depression only exists a certain way excludes and can even alienate people who don’t experience depression in that particular way.

It makes a lot more sense to me to consider everyone with depression as a unique individual who may have multiple factors contributing to their depression. When those factors are identified, they can be addressed in whatever way seems most helpful for the individual.

Trying to fit everyone under the umbrella of a particular “root cause” for depression will inevitably leave some people out. Throwing meds at someone whose depression is heavily influenced by unaddressed trauma is likely to be just as ineffective as having someone whose illness is quite biologically rooted go to psychoanalytic therapy to explore their Oedipus complex.

For now, science hasn’t given us a lot of answers about whether a root cause for depression exists; only more questions. Maybe we’ll get there, but for now, let’s throw away the boxes, and recognize people for the complex individuals that they are.

book cover: Managing the Depression Puzzle, 2nd Edition, by Ashley L. Peterson

Managing the Depression Puzzle takes a holistic look at the different potential pieces that might fit into your unique depression puzzle.

It’s available on Amazon and Google Play.

32 thoughts on “Is There a Root Cause for Depression?”

  1. I do not have a degree in medical science, and even if I did, I wouldn’t pretend to know everything there is to know about the human brain and it’s conditions, because as you mentioned, everyone is different. I must agree with you here. I also don’t believe there always is a cause, you can dig & dig, and there may be “triggers,” for depression, but it can also just be a chemical imbalance, there isn’t necessarily a specific cause or cases to depression. I think sometimes “we” get too caught up on trying to fix people. Instead of ending this stigma that having depression means something is wrong. It’s okay to not be okay. And sometimes I think people need to hear that. They’re not abnormal because they feel sad or can’t get out of bed, or whatever. I think we need more acceptance than fixing, but that’s just my personal belief.

  2. My depression stems from my childhood and there’s no way to pull it out by the root. I would have to change the family I was born into which is impossible. I’ve had mild depression since I was very little, and occasionally, episodes of major depression. It takes multiple triggers to lead to a major depressive episode that can last months. After a while, I’m able to pick up the pieces, move on, and get off of the meds. I’m currently med-free until I need them again and the doctor is aware that I quit taking them. I know I shouldn’t suddenly stop taking antidepressants and my doctor was informed.

    Lately, I’ve had to do things to protect my delicate mental health which includes eliminating as many of the triggers as possible, as suggested by the CBT therapist. It’s a good solution short-term but I know I can’t sustain it forever. I practically ran away from social media because I couldn’t deal with it.

    1. That’s great that you’re working on being proactive around triggers. Some triggers will be inevitable, but good to take control over the ones that aren’t.

  3. For me it doesn’t matter where it stems from! Can we now take it away please? 😯 I think that maybe there is predisposition in the genes. But as I feel it at the moment, for me, the life experiences enhance that vulnerability. I am fully aware that people can be ‘just’ depressed with ‘no difficulties’ in life (which is impossible). But hormones also play a role, the support you have… I once red that poor people are not as depressed as other people. One, they are not getting diagnosed and 2nd they tend to attribute the depressive feelings ‘to life’. It is very complex and each person is different. There is not 1 pill that will make ‘all the depression of the world’ go away and there is not one psychotherapy to ‘fix’ all. I believe depression has a function and that function is for me to let me heal through this and in a more unpleasant frame: to keep me alive through shielding me from other harm. A bit cryptic, sorry, but I don’t know how to phrase it more gently.

  4. very good subject! no matter how hard they try to fit all people in one category, it simply won’t work! we all have different genetic predisposition for one disease or another; to add, with depression it’s about having one trigger after another during our life, which increase our cortisol level and makes us more prone to develop true depression ! And as you have mentioned, Medications alone, without truly treating the trauma (trigger) with therapy {in my opinion} wont be as effective!
    Thanks for sharing this! More medical professionals should read this !

  5. Mine depends on the day, so it’s pointless to look for a root cause. Sometimes I’m depressed because of physical pain. Other days I’m in a dark place because of my wasted life. Other times I miss my mom so much it’s unbearable. Then there are past things I go over & over trying to resolve… yet other times I can barely remember them!

  6. I have taken classes in psychology in the past. I feel like this is how it is taught to many people going into the field. It is hard to see how it can be biological when it is taught that it comes from trauma.

    I would say mine stems from trauma. I was bullied through all my years in school until I graduated high school. I know that was the main cause. It could have been my upbringing too. I don’t know for sure though.

    I do think sometimes there is no cause. It can be learned. If you are raised by someone who has a mental illness, a child can pick on it.

  7. I’ve found that most therapists I’ve encountered or had treatment from, want to do that root identifying though. I’m not sure WHY either. Maybe it’s so they can put on the proper kind of mental bandage? Prescribe the correct treatment? It’s never helpful. And if ‘they’ ever do find out what caused my own depression, I’ll willingly listen. Because it’s not ONE thing…it’s a bundle of different things, environment, genetics, brain chemistry, pain, physical problems, unhealthy habits. It’s so convoluted that the whole “root cause” idea has to fly out the window in my case. It’s not one thing, it’s LOTS of things and yeah it can be argued that a ‘root cause’ (unidentified) caused the rest, but I just don’t think so. And maybe that contributes to the whole picture…if we aren’t willing to embrace the idea that one thing caused our unhappiness (as such), are we therefore unwilling to be healed. The last thing is the idea that once that root is identified, and figuratively pulled out, that the depressive is ‘cured’. Right. Personally I can’t be cured. I can take my meds and monitor the situation and be vigilant that I’m doing the best things for treatment of my depression, but there is no cure. Education is key. Thanks for providing that to your readers!

  8. In my opinion, (I too have had trauma in my life, Lord knows I have), however… I think that my trauma has been worked through quite well overtime in which I sought therapy.
    When I have suffered through bouts’ of depression, I don’t reflect on the past trauma. It’s just my mood slips away fro me. No trigers, it just sinks. When it sinks, that’s when I’m in trouble.
    Knock on wood, I seem fine for now. But, I am truly afraid of for how long.

  9. As with all complex issues, looking for a single cause as a definite answer will most likely fail. Personally, I don’t think it’s too important to know these causes anyway. We are probably not capable of recognizing every single one of them but we still have to put up with the consequences in our lives. I don’t need to know exactly why I’m reacting in the way I do, as long as I am able to find strategies in dealing with certain issues. Life is often incredibly unpredictable, hence uncontrollable. I used to avoid as many potential triggers as possible, just to make sure I would be able to go through the day relatively unharmed. But life laughs at you, if you try too much to control it – so, this attempt was doomed to fail.
    Now, I’m building my mind and habits in a way which allow me to deal with unexpected events easier and even get something out of them. I have been reading a lot recently about post traumatic growth research which allowed me to change many of my long-hold but toxic internal views about myself. I don’t know whether this is the answer to all my questions but so far it’s working and that’s the only thing which matters right now.

  10. I felt that getting to the root of my issues was helpful in terms of understanding myself. When I became depressed, I didn’t understand myself at all and couldn’t think of a reason why I would be depressed. I now understand myself and the things I’ve experienced much better. I would not say that has ‘cured’ me, though, and it did get to a point where my therapist didn’t feel that there was much more she could do for me. Probably there are a mixture of factors rather than one cause, and certainly there isn’t one solution for me.

  11. I agree with you. This also relates to any mental illness. Not everything is related to trauma. I experienced bullying in high school and also got my heart broken at 19 which I think is part of why I developed anxiety. I also think it’s because I’m a highly sensitive person. Those tend to suffer more from anxiety and depression. I agree that everyone is different so the solution will also be different.

  12. I like this piece and agree with you, and many other commenters here. As someone who has a “moderate complexity” illness, as put on my psychiatric paperwork, it is so hard to hear people say I just need to unlearn my trauma. I’ve had anxiety since early childhood, and developed bipolar depression in middle school… sure, trauma happened throughout my life as with everyone’s lives. I can do the work, struggle through “unlearning trauma” (whatever that really means), and still be biochemically predisposed to the mental illnesses I have. I have family members with the same symptoms and diagnosis. So honestly, I don’t care if there is a root cause and I don’t care to find it. What I want is the mechanism to help get myself out of bed, to find healthy coping mechanisms, to use my manic episodes productively rather than recklessly — and none of that is going to come from exploring the root cause of my illness.

  13. What a great read. Therapists tend to put us all in one category. Saying it doesn’t matter where it comes from…”this” is how it’s treated. I think there are many reason for depression..and anxiety. This article has made me see that more clearly. One can push and push ….for the treatment to work…but we are not all one in the same. There are many reasons for our illness.

  14. You are absolutely right. I can’t agree with you anymore:)

    As humans, we are complex organisms with intricacies and nuances of human experiences. We should be seen as a whole being instead of just certain parts (for example, biological made-up).

  15. Great post and we’ll laid out reasoning. Thanks so much for sharing. I would say I know exactly where my depression/PTSD comes from but it makes no difference in how often episodes come back or how I deal with it. I agree with you: the reasons are complicated and also how to make life livable for someone who is affected. For me dealing with my mental health more like a quest: finding my own Holy grail of measures that keep me sane. 😎

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