Los Angeles
The 44-year-old has children Ava, 20, and Deacon, 16, with ex Ryan Phillipe and seven-year-old Tennessee with husband Jim Toth.
During an interview on a podcast, she opened up about her battles with mental health over the years, admitting she first had therapy at the age of 16, reports mirror.co.uk.
Witherspoon said: "I definitely had anxiety. My anxiety manifests as depression so I would get really depressed. My brain is like a hamster on a wheel and it won't come off, I've been managing it my entire life."
Talking about "different experience" after each child, she said: "One kid I had kind of mild postpartum, and one kid I had severe postpartum where I had to take pretty heavy medication because I just wasn't thinking straight at all, and then I had one kid where I had no postpartum at all."
The "Legally Blonde" star explained how she was "completely out of control" after Ava was born.
She said: "We don't understand the kind of hormonal rollercoaster that you go on when you stop nursing. No one explained that to me.
"I was 23 years old when I had my first baby and nobody explained to me that when you wean a baby, your hormones go into the toilet. I felt more depressed than I'd ever felt in my whole life. It was scary."
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