The UK’s health secretary, Wes Streeting, has joined those raising alarms about “overdiagnosis” of ADHD, autism and mental health conditions in recent months. He has now ordered a review of how the NHS diagnoses them. But clinicians Oladayo Bifarin and Dan W. Joyce see something very different in their day-to-day work.

Diagnosis, they argue, has become the only reliable route to support in a system buckling under long waits, rejected referrals and overstretched staff. It is not that people are suddenly exaggerating their distress. It is that poverty, unstable housing and fragmented services leave them with nowhere else to turn.

Meanwhile, the reality for many girls is that their conditions aren’t diagnosed until their late teens or early adulthood. New research sheds light on why.

Also today, a new study shows that warming in south-east Greenland is activating “jumping genes” in polar bears, reshaping their DNA in ways that may help some populations adapt even as climate change continues to threaten the species.

And in Denmark, chemical analysis of pine tar from a 2,400-year-old boat, complete with a preserved fingerprint, reveals that its warriors came from the distant Baltic and shows that long-distance seafaring predates the Viking age by centuries.