Millions of American adults suffer from depression and anxiety symptoms at any given time, making it the most common mental illness in the United States. Among the nine different types of depression a person can be diagnosed with, high-functioning depression may be the most elusive. For a unique group of people, this often debilitating mood disorder can be suppressed enough for them to carry out daily responsibilities.

What happens to a person who can live through their day-to-day lives in the shadow of depression or anxiety? Depression that still allows a person to live a high-functioning life can seem like a deceiving term, which is why it’s more often referred to as low-grade depression. Chronic depression, also known as dysthymia, can cause decreased or increased appetite, decreased or increased sleep, fatigue and low energy, lack of productivity, feelings of hopelessness, and low self-esteem.

According to Harvard School of Public Health, chronic low-level depression can last an average of five years in adults or one to two years in children and teens, and while it doesn’t completely cripple a person, it can hinder her ability to live life to its fullest. Losing zealous enthusiasm for work, school, family, and social activities can make life seem bleak, which often leads to episodes of major depression in 75 percent of cases.

Because of the high risk of major depressive episodes, those who have low-grade depression should seek immediate treatment at the first sign of an issue, though it can be difficult to unmask the disorder; it often presents itself as a string of bad days or feeling low throughout a season or semester. College student Amanda Leventhal explained the struggle of maintaining a normal class schedule while living with high-functioning depression.

Living In The Shadow

From the outside, Leventhal was an overachiever. But inside her medicine cabinet sat a bottle of Lexapro, which is used to treat anxiety and major depressive disorder — a medication she was prescribed as a teenager. At the time, her psychiatrist said it was teens like her who whose conditions were the scariest.

Teens and adults who can pull off a normal-seeming life in public, yet suffer in private, eventually succumb to the pressures of success. Even those in their closest circles have no idea they are experiencing depression. Because depression and anxiety have distinct symptoms, like dropping grades, performance, or mood, those who are high-functioning can often mask themselves and pretend like everything’s okay when in reality it’s quite the opposite.

The stereotypical picture of depression and anxiety limits people from identifying those at risk, and makes it difficult for those suffering to identify it themselves.

"No matter how many times we are reminded that mental illness doesn’t discriminate, we revert back to a narrow idea of how it should manifest, and that is dangerous,” Leventhal explained in an editorial published on Upworthy. “Watching person after person — myself included — slip under the radar of the 'depression detector' made me realize where that fear comes from.”

According to the Anxiety Depression Association of America, anxiety disorders are highly treatable, however, roughly one-third receive treatment. By opening up communication lines through routine check-ins with friends and family, it can be easier to spot those who are quietly suffering but may not be exhibiting the typical symptoms of depression and anxiety.

Learn how mindfulness therapy is helping those who suffer from depression. Read here.