Depression reduces capacity to learn to actively avoid aversive events
eneuro.org
eneuro.org
When I'm really down, I can't bring myself to care about "aversive events". I might even welcome them a little bit, both because they fit my understanding better (everything is proceeding as it should be, this ant eating my flesh makes sense) and because it's an opportunity to feel something at least. For me anyway, depression is more about absence of affect than feeling "sad", and ironically it is maddening (and yet, in a sense I can't bring myself to care.)
Then again, my explanation suggests that depressed people ought to be better at avoiding harm through inaction, and I didn't see that in the abstract?
Another hypothesis is that you could stop at "Depression Reduces Capacity to Learn". It feels like all mental processing is muted, and especially any forms of change. I guess you could do a study where you have to learn to actively prevent an aversive event for someone else. But the 1st hypothesis may still apply: depressed people may still care less about harm to someone else (than if they were not depressed). But at least you could separate out whether it's only because depressed people don't care what happens to themselves.
Of course that mental state would hinder learning, you're missing all the brain signals and reward feedback to care about anything.
That's depression's "twin" sister (with a different personality) anxiety taking command of your behaviour. It's well-established now that obsessive-compulsive and avoidance behaviours are linked to anxiety. Both depression and anxiety feed each other.
The ability to make any mental and physical effort is greatly reduced to "depressed" levels.
It is the subconscious version of a situation where you need to climb out of a pit, but the walls are perfectly flat and oiled. Even though you need to get out of the pit, instead of scrambling, you just sit down.
The situation may not really be like that, but some deep cognitive machinery has concluded that it is.
It isn't anything like sadness. Although sadness could be part or proximate cause of a particular depressive episode, it is neither a necessary or sufficient condition.
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I do believe depression has a real purpose. To turn off motivated but misdirected behavior, and force us to perform a reset of deeply held assumptions, expectations and motivations.
Pain effectively changes our expectations and behavior in the moment. Depression is like pain for complex situations. It forces major change, by disabling our current ineffective directives and giving us "time out" to slowly rewire. Until the subconscious believes we have found a new mental path, more aligned with reality, and lets motivation flow again.
But like battle surgery, it is a blunt instrument for doing something profound, and may inflict damage as well as repair it.
And when life circumstances don't let us take the pause and rest our brain is trying to enforce, it is a bit of living hell.
This is how SSRI has felt for me also, incidentally: an even deeper apathy, setting in from lack of any emotion at all.
In a scenario where a disaster has negatively affected the primary productivity of the local food web (e.g. volcano, forest fire, bolide, plague or tsunami), the groups of social species that exist in an environment are likely to engage in internal strife until the food web productivity the group subsists on has returned to normality. Phenotypes which reduce activity across the board without making any changes to their distribution of activities, just hoping for things to get better on their own, are likely the phenotypes that are most successful at surviving to reproduce within conditions of intragroup strife when these infrequent disasters occur.
If this line of reasoning bears out to correctly describe the actual selection pressures that have led to the genes for depression evolving, it follows that what we call major depressive disorder is in fact the genome seeing and carrying out false positives for needing the famine-survival strategy.
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Incidentally, I first came across the theory I'm repeating here on Steven Byrne's neuroscience blog, if you want an avenue for finding sources.
My understanding is the existence of selection does not necessarily mean every trait that exists right now has an evolutionary benefit. It is more coarse grained that anything that doesn’t prevent you from breeding is acceptable. Depressed people are not made infertile by their depression, so there will be a subset of depressed people (assuming depression even has a hereditary component). This doesn’t mean the trait of depression has an advantage in order to exist, it just isn’t so much of a disadvantage that it doesn’t exist.
Only the system as a whole must carry superior fitness, not each of its individual components. Given a sufficiently complex system, its rather expected that there will be negative, or even outright destructive functions that arise. You can certainly try to find a positive reason for why cancer, disease, death during conception, etc exist, but there is a much simpler explanation.
Depression in this view, isn't something outright that was adaptively constructed, but merely a side effect of how the mind works.
Note: this is a speculation, not assertions of fact
Evolution functions not at the level of groups, or even individuals, but genes inside of individuals.
Most of the time thinking of it as group selection at the genetic level (=individuals) does work, fortunately.
Its entirely normal to be negative, or to ignore stimuli, or decide not to do things. In some situations, say if you were trapped in a cage your whole life, you'd agree it'd be entirely normal to be depressed. It would make no sense to waste energy running around hitting iron bars that won't break.
In this sense, depression is somewhat of a social construct. We determine someone is depressed because we believe their reaction to the environment to not be normal.
Imagine for a moment, a version of depression that appears after someone gets their reproductive member cut off (perhaps encounter an angry lion?), but they are still around to compete for food with the extended family's children.
Totally agree with your first sentence though. And even if there is a plausible adaptive function it may have only been adaptive in the past, or might be a side effect of some other adaptive function (see sickle cell anemia), or a host of other possibilities.
I think the basic criticism of group selection is that at an individual level it can be beneficial to go against the group's goal, and you need to explain why that doesn't happen (even very small advantages are rapidly boosted by selection). This is one of the great puzzles of selection - how does cooperation evolve from selfish interests? The theory of group selection just asserts that it does, which is not very satisfactory.
Patience, "biding our time", "hunkering down", etc. are actual emotional states we can experience and recognize, and depression doesn't feel even remotely like for most people as far as I'm aware.
Also, this explanation would only really work if the entire group entered a dormant depressed state together. Otherwise, the non-depressed ones would capitalize the tribe's resource and everyone would still end up screwed. But depression doesn't seem to have that sort contagious social component. On the contrary, when someone is depressed, the immediate response by people around them is generally try to "cheer them up" or encourage them to exit that depressed state. And while the depressed person is likely conveying a whole lot of negative sentiment, most aren't actively attempting to get the people around them to be depressed too. That's the last thing most depressed people want.
True, but that is when times are generally good. I doubt people would be "cheer up" in an actual disaster situation.
From what i understand depressed people generally do well in disaster situations because they can still focus on critical tasks without getting overwhelmed by all the other bad stuff going on that isn't an immediate problem. (Possibly that's just a popular conception from movies. No idea if its true)
I agree.
> Patience, "biding our time", "hunkering down", etc. are actual emotional states we can experience and recognize, and depression doesn't feel even remotely like for most people as far as I'm aware.
But I don't think that's a valid counterargument. Depression doesn't need to feel like that or be motivated by that in order to be selected for. As long as it has the same effect as someone actively choosing to reduce consumption, the argument works. (Again, I'm still skeptical of the argument.)
> Also, this explanation would only really work if the entire group entered a dormant depressed state together.
That's valid, though to salvage the argument, you could say it applies to situations where active behavior turns out to be maladaptive. Perhaps fleeing the volcano causes you to inhale more gases and definitely die/fail to reproduce, whereas moping in place gives you a chance to luck out and be in the right place at the right times and thereby survive. That's a stretch, but the other examples are better: maybe the active people compete and kill each other off. Or the active people catch the plague while trying to help out.
Actively avoiding harm might even be the better approach 99% of the time, and yet the 1% where inaction is better means that the trait can survive. Say everyone has an innate x% chance of being active. Event 1: 60% of active people survive, 40% of inactive do. Repeat several times. Event N: the soldiers find and kill 100% of active people and 75% of inactive. The survivors will not have x=100.
Related example: dinosaurs and small mammals. Big things did really well until they didn't.
An explanation for that behavior is that this kind of reaction serves as protection against the contagion. It doesn’t help the depressed but the environment around them, to not join in and feel the feelings of despair and hopelessness.
According to some theories, depression means other feelings like anger and anxiety are being suppressed - resulting in transference and counter-transference.
Yes, my not-well-formed pet theory around depression is that in most cases it's a sort of second-order effect of another emotional state like anxiety. Sort of a stalemate when at war with one's self.
There’s an ADHD specialist, a neurologist, who wrote a book called “ADHD Does Not Exist”. His core argument is that ADHD is not a single disorder but a collection of symptoms that cluster together from many different underlying causes. https://isbn.nu/9780062266743
I remember from my days studying to be an actuary that the population that can best estimate mortality odds from the gut are actually the depressed. (Most of us tend to be way too optimistic about common risks and pessimistic about uncommon ones.)
This was also used to explain mammalian postpartum depression, when the mother has to make a wretching call as to whether to keep the offspring given its health, her health and the environmental context.
My word... Could they have phrased that any less clearly?
As I understand it: the more depressive symptoms the subjects showed, the less likely they were to actively avoid bad outcomes (unless there was some other associated reward).
ChatGPT, asked to translate to a high schooler: "Basically, this study found that young people with depression sometimes struggle to break automatic habits, especially when they’re trying to avoid something bad and there isn’t a prize or reward for doing it."
The translation is just as much of a word salad as the original, just with simpler vocabulary. Worse, it mangles the key point.
Prepotent responses aren't "automatic habits," but overriding responses (e.g. pain) [1]. The "sometimes" qualifier is unsubstantiated when describing "association". And the struggle isn't amplified ("especially") when avoiding something bad absent reward, the first part of the sentence is conditional upon the absence of a reward. (It's nonsense to say pool drownings are especially common in pools.)
Not relevant. I'm not trying to break down the original text, that was done adequately by the top comment. I'm showing why the LLM summary is nonsense.
The article claimed it is a failure to learn whereas the phrasing from ChatGPT results in a much wider implication. Failure in a struggle to do something could imply a moral failure. If that's the message people get from this research, then there's a real risk it could worsen depression.
Workplace Example
Scenario: An employee has a colleague who tends to send aggressive emails if they don’t receive updates on time.
Healthy Active Avoidance: The employee learns, “If I send a quick status update every morning, I avoid the stress of hostile emails.” They adopt this as a habit.
Depressive Active Avoidance Deficit: A person with depressive symptoms may take longer to make this connection or fail to act even after realizing it. They know sending updates might help, but initiating the behavior feels too effortful or pointless. As a result, they keep receiving stressful emails, reinforcing the feeling of helplessness.
Example:
Case 1: Subject tries piano sight-reading exercises, if they get less than 80% accuracy a loud annoying horn will blare. Then subject goes again and try to improve the score.
Care 2. Subject tries piano sight-reading exercises, and if they get less than 80% accuracy they get notified that they didn't succeed at the test. Then they go again and try to improve their score.
The article strongly implies depression will make improvement more difficult in case 1 by the amount found in the study. But it doesn't necessarily imply that (or anything strongly) for case 2.
Your summary strongly implies that depression impedes progress in both cases at the same rate as the outcome of the study.
I'm not a domain expert but I'm going to guess "having bad outcomes" is as poor a paraphrase of "overriding prepotent responses" here as "having functions" would be to characterize functional programming languages.
So, you're saying that the study was narrower in scope and that the results are only applicable to specific bad/negative outcomes?