Suffering from anxiety often? A common plastic chemical may be affecting your brain, says new study

Anxiety affects millions of people worldwide and is often linked to factors such as stress, genetics, lifestyle habits and mental health conditions. However, researchers are increasingly exploring whether environmental factors may also play a role. A new study has now pointed to a common chemical found in many plastic products, suggesting that exposure during early development could have lasting effects on the brain and behaviour.

The research was presented at ENDO 2026, the annual meeting of the Endocrine Society in Chicago. Scientists from the University of Buenos Aires School of Medicine in Argentina examined the effects of di-(2-ethylhexyl) phthalate (DEHP), a plasticizer widely used to make plastic products more flexible.

Common chemical found in everyday products

DEHP is present in a variety of items people use regularly, including medical devices, toys, shower curtains and raincoats. Previous studies have shown that DEHP and the compounds produced when it breaks down can affect several systems in the body, particularly the reproductive and nervous systems.


Researchers wanted to understand whether exposure to the chemical before birth and shortly after birth could influence anxiety-related behaviour later in life.

“This research demonstrates that one of the most widely used plasticizers worldwide is capable of causing behavioral changes when the subject is exposed during the prenatal and immediate postnatal developmental stages, with this effect lasting over time,” said Osvaldo Juan Ponzo, M.D., Ph.D., professor of physiology at the University of Buenos Aires School of Medicine.

What the study found

For the study, pregnant rats were given DEHP daily from the beginning of pregnancy until their offspring were weaned. Once the male offspring reached adulthood, researchers assessed their behaviour using an elevated plus maze, a common test used to measure anxiety in rodents.

The rats exposed to DEHP during development showed signs of increased anxiety. They spent less time exploring open areas of the maze, remained longer in enclosed sections and displayed more freezing behaviour, a common indicator of anxiety.

The findings suggest that exposure to DEHP during critical stages of development may cause behavioural changes that continue into adulthood, even after exposure has ended.

Possible way to reverse the effects

Researchers also explored whether the behavioural changes could be altered. Some rats received GABA agonists, compounds that activate a key neurotransmitter involved in regulating brain activity, while others were treated with testosterone.

The treated animals showed fewer signs of anxiety compared to the DEHP-only group.

“This work demonstrates that contact with DEHP in the early stages of life could modify behavior with regard to anxiety, even in the absence of DEHP exposure in adulthood,” Ponzo said. “These neuroendocrine changes can be reversed by treating with GABA agonists or testosterone.”

While the study was conducted in rodents, researchers say the findings raise important questions about how exposure to endocrine-disrupting chemicals during early development may affect long-term brain health in humans. More research will be needed to determine whether similar effects occur in people.