Benzodiazepines are a highly effective group of pharmaceutical
drugs that help millions of people cope with anxiety, insomnia,
and panic disorders each year. These drugs work by binding to
receptors in the brain and enhancing the effect of a
neurotransmitter called GABA. But humans aren’t the only animals
with GABA and GABA receptors; several other species—including
many types of fish—are similar to us in this aspect of their
brain chemistry. And, thanks to the huge amount of prescription
drugs that are flushed down the drain (American medical care
facilities alone may flush as much as 250 million pounds of
pharmaceuticals a year), these species are inadvertently being
exposed to high concentrations of benzodiazepine in rivers,
lakes, and streams. In this week’s issue of Science, a group of
researchers shows exposure to these drugs can cause significant
behavioral changes in fish, changes that could potentially alter
ecosystem dynamics. Working in Sweden, the scientists found that
treated wastewater had conce