Depression and anxiety are afflicting Americans who are concerned at the fate of the environment, according to a study of the mental health effects of climate change.

Those hit hardest are women and people with low incomes who worry about the planet's long-term health, said the study published this week in the journal Global Environmental Change.

Depression and anxiety are afflicting Americans who are concerned at the fate of the environment, researchers have found. Credit:Michele Mossop

Symptoms include restless nights, feelings of loneliness and lethargy.

"Climate change is a persistent global stressor," Sabrina Helm, lead author of the paper and professor of family and consumer sciences at the University of Arizona, said.