It has been said that "ADHD rarely travels alone." This refers to the high incident rate of having ADHD and at least one other psychiatric disorder. Some experts put this as high as 90 percent of individuals, although a more accepted estimate would be anywhere from 40 percent to 65 percent of those with ADHD will also be diagnosed with a second disorder at some point.
The following table shows the most common comorbid conditions and their rate of prevalence in the ADHD community, according...

