Dr. Matt Walker

This is an area of work that we've been interested in and doing a lot of research on for about 20 or so years now.

And I would say that probably the most striking statement I can offer up front is the following.

In that 20 years of research, we have not been able to discover a single psychiatric condition in which sleep is normal.

And to me, it has taught me everything that I need to know about this very intimate bi-directional relationship between your sleep health and your mental health.

And you're right to emphasize that notion of mental health because we're not just going to speak

about some of the sort of challenging aspects of sleep and psychiatric disorders.

But we'll speak about some of the benefits that sleep can provide when you get it to turn the tables and we move in the direction not of mental illness, but we move in the direction of mental wellness.

So I'm excited to sort of make sure that I don't fall prey to that.

Stepping back still though, what about this relationship between just sleep and our basic emotional regulation and our emotional stability?

I'm sure everyone has seen the example or had the example as a parent of that parent holding a child and the child is crying and they look at you and they say, well, they just didn't sleep well last night.

as if there's some miraculous parental knowledge that bad sleep the night before equals bad mood and emotional reactivity and regulation the next day.

And some years ago now, we were fascinated by this, but we couldn't really unearth basic science that would help us explain what was going on and why that was so clearly the case.

So we did an initial study where we took a group of healthy people, no signs of psychiatric illness or emotional instability, and we gave them a full night of sleep or we sleep deprived them.

And then the next day we put them inside of a brain scanner and we showed them a whole range of emotional visual images ranging from very neutral all the way up to quite unpleasant and negative.

And we were looking at how the brain was reacting to those emotional experiences with versus without sleep.

And the structure that we'd initially focused on was a structure that you've spoken about before called the amygdala.

And you actually have one on the left and the right side of your brain.

And the amygdala is the centerpiece region for the generation of emotional reactions, both positive and negative.

But here we're focusing on that aversive, that negative aspect.

And when we looked at that structure in people who are sleep deprived, what we saw relative to the people who'd had a full night of sleep was a 60%, six zero, 60% increase in amygdala responsivity.