Emails released by Wikileaks show that Hillary Clinton looked into a drug used to treat sleepiness and Parkinson's disease after she apparently began suffering from "decision fatigue" back in 2011.

Clinton sent an email to close confidante and advisor Cheryl D. Mills on August 19, 2011 featuring the text of an article entitled Do You Suffer From Decision Fatigue?

The article talks about how people in positions of power and influence can suffer from "decision fatigue" that causes them to be "low on mental energy" and prompts the sufferer to "become reckless" and "act impulsively".

The article also explains how "decision fatigue" could explain why "ordinarily sensible people get angry at colleagues," which is possibly a nod to Clinton's infamous temper tantrums that have left her staffers in tears.

"Wow that is spooky descriptive," wrote Hillary in response to the article.

In a separate email sent two months later, Hillary received information from her top foreign policy advisor Jacob Sullivan about a drug called Provigil (Modafinil), which is used to treat "excessive sleepiness in patients with Parkinson's, Alzheimer's, and multiple sclerosis," as well as "excessive sleepiness caused by narcolepsy".