18 participants that were comorbid with alcohol use disorder. epidemiology gad is often estimated to affect approximately 3–6% of adults and 5% of children and adolescents. although estimates have varied to suggest a gad prevalence of 3% in children and 10.8% in adolescents. when gad manifests in children and adolescents, it typically begins around 8 to 9 years of age. estimates regarding prevalence of gad or lifetime risk (i.e., lifetime morbid risk (lmr)) for gad vary depending upon which criteria are used for diagnosing gad (e.g., dsm-5 vs icd-10) although estimates do not vary widely between diagnostic criteria. in general, icd-10 is more inclusive than dsm-5, so estimates regarding prevalence and lifetime risk tend to be greater using icd-10. in regard to prevalence, in a given year, about two (2%) percent of adults in the united states and europe have been suggested to have gad. however, the risk of developing gad at any point in life has been estimated at 9.0%. although it is possible to experience a single episode of gad during one's life, most people who experience gad experience it repeatedly over the course of their lives as a chronic or ongoing condition. gad is diagnosed twice as frequently in women as in men and is more often diagnosed in those who are separated, divorced, unemployed, widowed or have low levels of education, and among those with low socioeconomic status. african americans have higher odds of having gad and the disorder often manifests itself in different patterns. it has been suggested that greater prevalence of gad in women may be because women are more likely than men to live in poverty, are more frequently the subject of discrimination, and be sexually and physically abused more often than men. in regard to the first incidence of gad in an individual's life course, a first manifestation of gad usually occurs between the late teenage years and the early twenties with the median age of onset being approximately 31 and mean age of onset being 32.7. however, gad can begin or reoccur at any point in life. indeed, gad is common in the elderly population. united states united states: approximately 3.1 percent of people age 18 and over in a given year (9.5 million). uk 5.9 percent of adults were affected by gad in 2019. other australia: 3 percent of adults canada: 2.5 percent italy: 2.9 percent taiwan: 0.4 percent