Childhood trauma isn't something you just get over as you grow up. Pediatrician Nadine Burke Harris explains that the repeated stress of abuse, neglect and parents struggling with mental health or substance abuse issues has real, tangible effects on the development of the brain.

In long-term relationships, we often expect our beloved to be both best friend and erotic partner. But as Esther Perel argues, good and committed sex draws on two conflicting needs: our need for security and our need for surprise. So how do you sustain desire?