Robert F. Kennedy junior, Donald Trump’s health secretary, wants to reduce attention-deficit hyperactivity disorder (ADHD) among American youngsters. That is a worthwhile goal, even as he attributes the country’s high rate of diagnosis to causes—such as artificial food colouring—that are marginal. The real reason is rampant over-diagnosis.

Elsewhere, we consider what China wants out of Ukraine peace talks. Xi Jinping has been a stalwart supporter of Vladimir Putin. Now, in what China’s top diplomat calls a “window of opportunity for peace”, it hopes to nurture its image as a great power.