Confusion lingers over health-related pros and cons of marijuana

50 years ago, the effects of chronic marijuana smoking on mental health were hazy. They still are.

Gene variant linked to Alzheimer’s disease is a triple threat

A genetic risk factor for Alzheimer’s disease works on multiple aspects of the disease, researchers report.

The way poison frogs keep from poisoning themselves is complicated

Gaining resistance to one of their own toxins forced some poison dart frogs to make other genetic tweaks, too.

Telling children they’re smart could tempt them to cheat

Kids who were praised for being smart were more likely to cheat, two studies suggest.

Intense storms provide the first test of powerful new hurricane forecast tools

From Harvey to Maria, this year’s powerful hurricanes are giving scientists’ latest forecasting tools a trial by fire.