This page on Depression is part of the Auxiliary section of the Beginner's Course
of the D.S. Dog Training Workshop, and an element of the Dog Science Network

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Understanding Depression in Dogs and Humans

An Introduction to an Exact Process

There is an exact process and a precise mechanism that causes both dogs and people to become depressed. That process is extremely well understood. Indeed, there is no mystery about it whatsoever.

It is, actually, a great scandal that with so many people suffering from depression, the psychological establishment has done such a poor job of getting the word out and explaining that mechanism to the general public.

The purpose of this page, then, is to explain the mechanism that results in both dogs and humans becoming depressed.

If you want to grasp the mechanism that drives depression, the first thing you need to understand is that someone's activity level, their level of depression, if any, and the amount of reinforcement they receive in the course of their daily life are all inextricably intertwined.

Reinforcement Generates Energy and Drives Activity Level

Essentially, reinforcement is anything you encounter in your environment that drives your level of activity. That is the nature of reinforcement. It is the energy source that fuels the behavior of dogs and humans alike.

Indeed, reinforcement is to behavior as fuel is to an automobile. It is that which produces the energy that makes behavior happen.

Most people think of reinforcement as being some type of reward that serves to increase the frequency of a response, and it is certainly true that reinforcement will increase the frequency of any given activity with which it is closely associated in time. So if you do some particular thing and it quickly produces a rewarding consequence, then, you are likely to begin doing more of that particular thing in the future.

However, in addition to increasing the frequency of those particular responses with which it is directly associated and closely associated temporally, reinforcement in general just tends to make people and dogs more active in general. The more reinforcement someone gets in the course of their day, the more active they are likely to be. That is why, as a rule, those who live extremely rewarding lives are very busy people.

A Dense Schedule = A Happy, Active Organism

A reinforcer, then, is really just some sort of reward that someone gets for doing something. It just makes sense, then, that someone who gets a lot of rewards for the things they do is going to do more things. Hence, someone who receives a lot of reinforcement during the course of their day can just naturally be expected to be more active, since they are getting more payoffs for doing more things.

When someone gets an enormous number of payoffs for the things they do, we say they are on a dense schedule of reinforcement. When someone is rewarded every time they make some particular response, we say that that particular response is being reinforced on a continuous schedule.

Sports stars are reinforced on a continuous schedule for many of the responses they make. Every time a basketball star shoots a basket the crowd cheers - every time. Therefore, we say that the basketball star's basket-shooting behavior is reinforced on a continuous schedule.

Some celebrities receive continuous reinforcement across the board, by which I mean that they are in a position in which they can draw continuous reinforcement for absolutely everything they do. They can find people who want to listen to everything they have to say and people who will pay them just for the chance to spend time with them. For some celebrities, there is not anything they do for which they cannot find someone who will reward them in some way for doing it.

People who live their lives on a dense schedule of reinforcement tend not only to be busy, they also tend to be extremely happy.

Ratio Strain

When a person is on a continuous schedule of reinforcement, we say they are on a 1 - 1 ratio of response to reinforcement. By which we mean that they only have to respond once before they receive a reward for having made that response. In comparison, if our subject had to make two responses before he could draw a reinforcer, then, we'd say that he was scheduled on a 2 -1 ratio.

Now, imagine that we were dispensing reinforcement to someone on a continuous basis, and that we were this person's only source of reinforcement. But imagine that, then, we began to thin-out the pay-offs so that over a period of many months, our subject gradually began to receive less and less reinforcement for making the same number of responses. We would find that as the level of reinforcement gradually decreased, our subject would become steadily less and less satisfied with the situation and he would also, over time, become less active in general than he had been previously. In other words, he would do fewer things during the course of his day than he did when his general level of reinforcement was higher.

If we just kept thinning the reinforcement out over the months so that our subject had to make more and more responses in exchange for less and less in the way of rewarding reinforcers, the ratio of response to reinforcement would eventually deteriorate to the point to where the poor guy would just throw up his hands - his paws, or whatever - in frustration.

At some point it will occur to him that maybe it's not worth the effort, and he'll start to wonder why he even keeps trying. That is called the point of ratio strain.

Ratio strain is the point of too much energy expended in exchange for too little in return. It is the point of If things don't get better, I don't know how much longer I can keep doing this.


When reinforcement falls below a certain level, people and dogs just stop responding. However, that should come as no surprise. Remember, reinforcement produces the energy that makes behavior happen. Therefore, when no reinforcement is forthcoming, lethargy soon follows. What you get, then, is an inactive organism that just tends to mope around.

When someone falls into a low energy, dysfunctional funk as a result of a thin schedule of reinforcement, that is by definition, depression.

Be they dog or human, that's what's happening when you are dealing with a depressed subject. They are operating under a schedule of reinforcement that is so thin that there are just not enough rewarding stimuli in their environment to keep them active and functioning effectively, not to mention happily.

Notice that when you feel deeply depressed you experience a sense of being out of gas, as though your inner reserve of spiritual energy has been depleted. You may have a sense that you need to somehow dredge up the strength to go on from within, the way a starving body must feed off its own muscle to survive. As opposed to being able to draw nourishment from external sources.

It really is very much a parallel situation when you are depressed. If you cannot draw reinforcement from an external source, then, you must deplete your own internal reserves if you are to push forward at all. However, since a person can only do so much of that, when external sources of reinforcement dry up, people and dogs tend to stop responding as they settle into a much less active state.

You'll notice that depression tends to occur at times of great loss, when we are separated from loved ones. That makes perfect sense if you take into account the fact that those closest to us reinforce us for everything we do in countless ways. Therefore, when we lose a loved one, we also lose an enormous source of reinforcement and an astounding number of reinforcers. And after all, those reinforcers generate the energy that fuels the responses that keep us happy and active.

Depression May Not Primarily Be a Psychological Problem

Although it sometimes leads to suicide and can, therefore, be extremely serious, truth be told, depression that is caused solely by a derth of reinforcing stimuli in the environment is not truly a psychological problem in the sense that it can conceivably be remedied with a non-psychological fix. For example, a person who is depressed secondary to ratio strain could be miraculously transformed if they suddenly got a high paying job where financial rewards began to flow freely and they were, at the same time, surrounded by co-workers who put them on a continuous schedule of reinforcement by dispensing praise and other social reinforcers for every effort they put forth in the workplace.

In that sense, many people who are depressed due to ratio strain may actually be suffering much more from a situational problem rooted in environmental factors than from a true psychological disorder in the sense that one usually thinks of such things.

Depression in Canines

Dogs do, indeed, become depressed, and the danger of an animal being stricken with that malady or incapacitated by ration strain is well recognized among those who work with service dogs of all kinds. For that reason, police officers who work with drug-sniffing dogs make it a point to plant contraband for the animals to find from time to time, to ensure that they won't go too long without finding something for which they can be rewarded, because if they do, the ratio may grow so thin they that they will simply stop working.

For a highly trained search and rescue dog, the reinforcing payoff comes when a victim is found alive. No survivors means no payoffs. Accordingly, it is said that after days of working their way through the rubble of the World Trade Center without finding anyone alive, the dogs who searched in vain for survivors grew visibly depressed.

German Shepherds understand ratio strain. They don't need anyone to explain that to them.

Most people don't recognize depression in their own family dogs. Rather, when they see the symptoms they simply chalk it up to the dog being mellow or lazy. Especially if a given dog is depressed pretty much all the time, it starts to seem like the depressive mannerisms displayed by the animal merely characterize the way he just naturally is.

You are most likely to observe depressive symptoms in your family dog if he is unexpectedly separated from the family members who usually meet his needs and, thereby, fuel his usual activities at their customary level. For example, if just you and the dog are left behind while his other usual human sources of reinforcement are away on vacation, you may well see the dog begin to mope around in a depressed manner. In fact, I once kept steady company with a Dachshund who late in life became known as the moper for that very reason.

Go to the index for this article

This page on Depression is part of the Auxiliary section of the Beginner's Course
of the D.S. Dog Training Workshop, and an element of the Dog Science Network