Women are almost twice as likely to experience anxiety as men, according to new research.
University of Cambridge researchers are calling for more resources to study the disorder, which is estimated to affect four in 100 people, and disproportionately hits the under 35s.
The study also found that people from Western Europe and North America are more likely to suffer from anxiety than people from other cultures.
The review of existing scientific literature, published in the journal Brain and Behaviour, suggests more information is needed on how anxiety affects marginalised groups.
It also highlights that people with other health conditions are often far more likely to also experience anxiety disorders.
Author Olivia Remes from the Department of Public Health and Primary Care at the university said: "Anxiety disorders can make life extremely difficult for some people and it is important for our health services to understand how common they are and which groups of people are at greatest risk.
"By collecting all these data together, we see that these disorders are common across all groups, but women and young people are disproportionately affected. Also, people who have a chronic health condition are at a particular risk, adding a double burden on their lives."
The annual cost related to the disorders in the United States is estimated to be 42.3 million dollars. In the European Union, more than 60 million people are affected by anxiety disorders in a given year.
The review showed that the highest proportion of people with anxiety is in North America, where almost eight out of every 100 people are affected; the proportion is lowest in east Asia, where less than three in 100 people have this mental health problem.
Women are almost twice as likely to be affected as men, and young individuals – both male and female – under 35 are disproportionately affected.
The analysis also showed that data on some communities - such as indigenous cultures in North America, Australia and New Zealand, and drug users, street youth and sex workers - was lacking or of poor quality.
Professor Carol Brayne, director of the Cambridge Institute of Public Health, said: "Even with a reasonably large number of studies of anxiety disorder, data about marginalised groups is hard to find, and these are people who are likely to be at an even greater risk than the general population.
"We hope that, by identifying these gaps, future research can be directed towards these groups and include greater understanding of how such evidence can help reduce individual and population burdens."