Thread by @scott_mintzer

Many people seem unaware of the impact of depression on cognitive function (i.e. thinking abilities).

I discovered this when a few small replies I made recently on someone’s thread garnered a total of a few thousand likes (and still counting).

So, a brief Tweetorial. /1

Impairment of cognition — meaning, impaired ability to think, remember, solve problems, etc. — is quite common in depression, and is a very common cause of cognitive complaints in medical practice overall.

There are two major reasons depression causes cognitive problems. /2

The first is that it makes you slower.

When you’re depressed, everything looks grey, and there’s no hope, so it’s awfully hard to motivate yourself to do things.

That includes thinking about things & solving problems. You might do it eventually, but it’ll take you longer. /3

Thinking is all about making connections — between a name and a face, between a problem and a solution, between ideas and words and images.

If you’re slower, you make fewer of those connections in a given amount of time. That means the speed of your thinking is impaired. /4

I’d make this analogy: depression is like a 30-pound backpack that you drag around with you wherever you go.

And for some of those people, trying to think when you’re depressed is like trying to run up a hill with that 30-pound backpack on your shoulders. /5

The second reason depression impairs cognitive function is also very basic, and it relates to many people’s complaints that they have trouble with memory.

It turns out that memory is a multi-step process, and the first step in the memory process is… attention. /6

Again, when you’re depressed, everything is grey, and there’s no hope. So nothing seems to matter all that much. And if nothing matters that much, it makes it hard to pay attention to things.

Oh sure, you heard what they said — enough to remember it for a few minutes. BUT… /7

…after that, the material needs to get moved into your brain’s long-term storage facility, so to speak, for you to remember it longer.

And if you weren’t really paying much attention — say, because you were too sad to care that much — it’ll never get there. /8

You will then experience that as difficulty with memory. Which is a fair enough interpretation, b/c you didn’t remember something.

But the problem isn’t really with the function of the memory circuits. The problem is with paying attention.

Which brings us to the good news. /9

The good news is that depression doesn’t do any actual damage to the brain’s structure.

It sure as hell affects how the machine FUNCTIONS… but the underlying circuitry is all still there, perfectly intact.

(At least, it isn’t damaged by the depression. More on this below.) /10

This means that if your depression gets treated (or goes away), your old thinking abilities will be there waiting for you.

Though it’s like exercise: you might have to “work out” your brain a little to get it all back. But if your mood is good, you’ll quickly get there. /11

The only time that won’t happen is if there’s another medical condition that might be causing the cognitive trouble AND the depression.

For example, I treat folks with #epilepsy. In these patients, there can be 4 separate causes of cognitive problems: /12

1. The seizures themselves, which damage the brain over time;
2. The underlying brain abnormality which is producing the seizures;
3. Medications;
4. Depression (which is extremely common in epilepsy patients).


Sometimes sorting this out can be challenging.

/13

Another situation that can be challenging is when an elderly person has cognitive impairment and is clearly depressed.

Is it the depression? Is it Alzheimer’s Disease (or something similar)? Maybe they have both?

(Depression is extremely common in patients with dementia.) /14

For many people who have depression and cognitive trouble, whether or not there is another underlying condition, it makes sense to be treated for depression.

If mood improves and thinking gets better, you have diagnosis and treatment all taken care of at the same time. /15

If mood improves and there is still a lot of trouble with thinking, then perhaps other tests or diagnoses might be considered, depending on the situation and the specific symptoms. /16x

P.S. Forgot to add: the reason you may never remember some of the things that happened when you were really depressed is because... you guessed it... you weren't able to pay attention to them well enough in the first place.

But once mood is fixed, you can pay attention again.