Two separate studies of clinical depression and anxiety disorders were conducted. People across 91 countries, more than 480,000 people, were surveyed regarding their clinical anxiety and/or major depressive disorder.
These surveys showed that clinical depression and anxiety are serious health problems all around the world:
- Non-western societies, even ones experiencing conflict, were reported to have less people with anxiety disorders than in Western societies
- 10% of people were affected by anxiety in North America, Western Europe, and Australia/New Zealand
- 8% of people in the Middle East were affected by anxiety
- 6% of people in Asia were affected by anxiety
- Depression had the opposite effect in Western countries, less people were likely to be depressed
- 9% of people in Asian and Middle Eastern countries, such as India and Afghanistan, had major depression
- 4% of people had major depression in North and South America, New Zealand, Australia, and East Asian countries like China, Thailand and Indonesia
"More investigation of the methods we use to diagnose depression and measure its prevalence in non-western countries is required, as well as more research on how depression occurs across the lifespan."
Lead author of the anxiety study, Amanda Baxter, also cautioned people on comparing mental disorders across different countries.
"Measuring mental disorders across different cultures is challenging because many factors can influence the reported prevalence of anxiety disorders. More research is also needed to ensure that the criteria we are currently using to diagnose anxiety is suitable for people across all cultures."
Both clinical depression and anxiety are more commonly found in women than in men.
This study found that for men and women over the age of 55, anxiety becomes less common. However, depression remains common throughout the lifespan.
About 4.7% of people (1 in 21) will have major depression at some point in time.
About 7.3% of people (1 in 13) currently suffer from anxiety, the most common of all mental disorders.
These two studies are the world's most comprehensive studies on clinical depression and anxiety. They are published as part of the Global Burden of Disease Study (GBD) that will be released later in the year. The GBD Study will contain estimates for 220 different diseases, including 11 mental health disorders.
Written by Sarah Glynn