Here’s How Antidepressants Are Changing Animal Behavior

Antidepressants are affecting the mating habits of European starlings, with females on Prozac showing to be less likely attractive to suitors.

Mental health is a huge problem, causing an increasing number of people around the world to struggle with day-to-day life. Now, it's revealed that the mental health medication also has adverse effects on wildlife.

How Birds Are Getting Prozac

In the new study published in the journal Chemosphere, researchers from the University of York reveal that antidepressants found in sewage treatment systems have adverse effects on starlings in the United Kingdom.

Traces of mental health medication make its way to sewage systems after getting consumed by people. Then worms, maggots, flies, and any other creatures feeding by the water absorb the antidepressant particles.

In turn, birds flock to these systems to feed on the insects and become infused with traces of medication.

Scientists Analyze The Birds

Kathryn Arnold and Sophia Whitlock have been observing the impact of Prozac on starlings for years, according to a report from the University of York.

For the study, the duo tested the effect of diluted concentrations of the medication on the birds using the following behavioral measures: the male courtship song and the male behavior.

"Singing is a key part of courtship for birds, used by males to court favoured females and used by females to choose the highest quality male to father their chicks," Whitlock says in a statement.

The team used 24 starlings, half of which were fed regular waxworms, and the other half were fed waxworms with Prozac at the high end of the range found in sewage treatment systems.

Decreased Singing, Increased Aggression

Even the low doses of antidepressants had a significant effect on the birds' mating habits.

Male starlings were discovered to sing twice as often and twice as long to their female counterparts who weren't exposed to Prozac.

Instead of engaging in their usual courtship rituals, the males were found to be more aggressive toward the females on Prozac. They were found to be more likely to chase, peck, or claw the females who were on the medication.

"Here is the first evidence that low concentrations of an antidepressant can disrupt the courtship of songbirds," Arnold explains. "This is important because animals that are slow to find a mate often won't get to breed."

She adds that it might be time to figure out what can be done to remove harmful chemicals such as antidepressants from the sewage system, especially with so many animal populations in sharp decline.