Dr. Matt Walker

That's the first issue.

And we don't have a clear understanding.

The second issue is that as soon as those patients with depression sleep after the deprivation,

the antidepressant benefit goes away and they go right back to being depressed again.

So yes, it's a mechanistically interesting process.

What is it about sleep deprivation that could alleviate depression?

And I'll explain why I think it can.

But it's not a sustainable one.

It's not a clinically viable one.

Why would it have that effect if it does?

Well, you and I discussed earlier in this episode that when you are sleep deprived, not only does your emotional brain become much more responsive to negative things, it also becomes much more responsive to rewarding positive things.

And one of the interesting things that I think people mistake about depression, they just think that when I'm depressed, I have sad mood, I have negative mood.

That's not entirely true.

One of the principal features of depression is something that we call anhedonia, which is an absence of having the ability to have hedonic responses.

In other words, you can't get pleasure from normally pleasurable things.

It's not an issue about sliding down to the negative.

It's the absence of being able to experience the positive that puts you on a track towards depression.

And what you and I discussed earlier in this episode is some of the work that we've been doing, where when you sleep deprive individuals, but you show them very rewarding based stimuli, they become much more reward sensitive.

And perhaps this is why patients will respond to sleep deprivation with depression, because they're too far away from that positive end of the spectrum.

They're not reward sensitive enough.