Depression is the leading cause of disability in the United States. Prevalence of major depression in the United States is approximately 7%, with differences by age groups and gender. The prevalence of major depression in 18- to 29-year-old individuals is threefold higher than the prevalence in individuals age 60 years or older. Females are at 1.5- to 3- fold higher risk to develop depression than males (DSM, 2013).
Until recently depression in children has been underrecognized. Now it is known that children and adolescents between 13 and 18 years of age have an 11.2% prevalence of depression, and 3.3% have a severe form of the illness. If the first episode of depression occurs in childhood or adolescence, the likelihood of recurrence