In July, Jason Fletcher, a professor Yale's School of Public Health, released a working paper concluding that depressed teenagers earn roughly 20 percent less on average later in life. This week, Fletcher has released a new paper looking at the consequences of childhood attention deficit hyperactivity disorder (ADHD), using data on some 15,000 Americans who were tracked from their teens to around age 30.

And much like in his depression study, Fletcher reaches some startling conclusions. They are summarized in the graphs below.

He finds that the overall, young people diagnosed with ADHD are about 10 to 14 percentage points less likely to be employed. If they do have a job, they earn about 33 percent less income. Only a small part of those differences, he finds, can attributed to factors such as how far young people with the syndrome make it through school. As you can see, the effects are worst for minorities and the poor, which Fletcher defines as living in a family that earns less than the median U.S. income.

Here are the employment impacts. 

And here's a breakdown of what happens to wages. 

One key thing to note here: The study uses data on students who were somewhere in seventh through twelfth grade in the 1994-95 school year. That means most would have been young children in the 1980s, when ADHD diagnoses were less prevalent than today and access to drugs like Ritalin would have been a bit more restricted. 

Ultimately, Fletcher argues that his findings are evidence that early childhood treatment of ADHD may be the key to heading off problems later in life. As he acknowledges, this is just one study -- one which has yet to be peer reviewed -- but the numbers he generates are certainly alarming.