Anxiety disorders are the most common form of mental illness in the United States. Each year, anxiety disorders affect approximately 40 million American adults, which means about 18% of American adults suffer from anxiety.

Among Americans suffering from anxiety, 6.8 million adults, or 3.1% of the U.S. population, have generalized anxiety disorder (GAD); 6 million adults, or 2.7% of the population, have panic disorder; 15 million adults, or 6.8% of the population, have social anxiety disorder; 19 million adults, or 18.7% of the population, have specific phobias; 2.2 million adults, or 1% of the population, have obsessive compulsive disorder (OCD); and 7.7 million adults, or 3.5% of the population, have posttraumatic stress disorder (PTSD).

It is estimated that nearly a third of American adults will suffer from an anxiety disorder at some point in their lives. Anxiety disorders also affect nearly one in four adolescents between ages 13 and 18. The U.S. isn’t alone: according to the World Health Organization, anxiety is the most common mental illness worldwide.