Welcome back to savvy psychologist. I'm Dr. J. Wu and I'm thrilled to be your new

host. I look forward to helping you meet life's challenges with evidence-based research, a

sympathetic ear, and zero judgment.

This week, let's ask the million dollar question.

How much sleep do you really need?

We all know sleep is important.

Shakespeare called it the sore labor's bath, balm of hurt minds, great nature's second course, chief nourisher in life's feast.

Less poetically, headlines these days seem to be shouting all sorts of dire warnings.

Sleep deprivation will make you slower and dumber.

It will give you Alzheimer's disease and heart attacks. One mattress advertisement

I saw simply said, you can only live seven days without sleep. Yikes, Talk about pressure to perform! Fear-mongering aside,

there is good evidence that sleep is important for health, well-being, and performance. A recent meta-analysis, including

over 1,600 participants, confirm that sleep restriction is associated with poorer attention and thinking.

We've known for decades that sleep deprivation disrupts mood.

For example, it can trigger manic episodes in those with bipolar disorder.

And now we're learning from researchers in Sweden and Germany

that insufficient sleep can even affect the microbiota in your gut. But how much sleep is enough. Is there such

thing as too much sleep? If you ask Dr. Google, you'll get over a billion answers. That's right, billion with a B. The most common

answer seems to be eight hours. Well that seems pretty straightforward, right? But where does

this number come from? And if you're thinking, Dr Google hasn't examined me, how would she know how much sleep I need?

Then you're asking exactly the right question.

We'll get to some tips and answers to the deepest sleep mysteries in a moment.

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