In a toxic relationship, you might let go of your usual self-care habits, Lawsin explains. You might withdraw from hobbies you once loved, neglect your health, and sacrifice your free time.

And now finally my own winnowed, older body, which still feels foreign to me. I had been a house for my family, and now I was empty. We moved the kids into a three-bedroom apartment in Brooklyn.

The healthiest participants at age 80 tend to have been most satisfied in their relationships at age 50. In other words, the secret to happiness isn’t falling in love; it’s staying in love.