The alarm rings just as the sun hangs in the night sky waiting to rise. A woman wakes up, and her eyes well up with tears.

She crawls out of bed feeling nothing but an awful headache and loneliness. Together with persistent negative thoughts, they accompany her like a best friend throughout the day.

An hour later the woman will enter her cozy office. She'll smile as if nothing happened, chat with co-workers and do her job like a boss.

You'd never know she lives with dysthymia, a high-functioning depression causing changes in appetite, sleep and emotions.

An estimated 350 million people world-wide suffer from depression.

Like 350 million other people worldwide, this woman tells no one about her condition and tries to continue working efficiently.

"This will never be my experience," you say. And that's the problem.

Lack of understanding is the most challenging aspect for depressed people to meet.

Most people equate depression with fatigue and stress, considering physical exercises and proper working environment enough for magical healing.

Well, magic can happen, but exercise and a proper work environment are not the case.

Here are five things people who suffer from high-functioning depression want you to know:

Co-workers don't realize the problem depth.

Depression is a difficult condition.

The problem is, it remains a taboo subject in most workplaces.

Many don't want to admit they're depressed, and that's among the core reasons why 80 percent of sufferers don't receive any treatment.

But even those who admit it get nothing because managers don't understand how to deal with them.

Steve Horvath, CEO of the Canadian Centre for Occupational Health and Safety, says, "It's a difficult challenge for employers because, ultimately, they have to address the issues of their own organization's culture."

People underestimate the problem of depression, and they don't understand how hard it is for a sufferer to function in the workplace.

It's so unbelievably hard for a sufferer of depression to function in the workplace.

Yet, 84 percent of managers consider it's part of their job to help depressed employees, but admit they need more training on how to do it.

Going to work seems close to impossible.

You see a person powering through their to-do lists and meeting all deadlines, so you would never believe them if they admitted their depression to you.

But far from all health problems are visible to the eye.

Far from all health problems are visible to the eye.

If a person continues working, it doesn't mean it comes naturally for them.

Depressed people find everything exhausting: Getting up, making their way to work, eating breakfast. They are all energy-consuming, but worth the larger-than-life effort for them to do.

Madhukar H. Trivedi, M.D., says, "Major depression is also associated with painful physical symptoms such as a headache, backache, stomach ache, joint ache and muscle ache."

And nothing hurts them more than misjudgment from others.

They try hard to look normal.

They work full-time. They're married with kids. They travel, spend time with friends and lead normal lives.

"Why are you sad? You're beautiful! You have a lovely family and dream job. Everything is fine!" you say, scratching your head.

Meanwhile, a depressed person has turmoil in their head.

Negative thoughts destroy them every minute, and they try very hard to be "normal."

From the outside, they look like someone who has it all together but their inner world doesn't agree.

From the outside, they look like someone who has it all together but their inner world doesn't agree with such a statement.

They won't recover after your don't-be-sad words.

"Don't be sad." "Try thinking positive." "It's all in your mind, change your perspective." "I know how you feel."

These are some of the worst things to say to depressed people.

They can't just "stop feeling sad." Their depression is a physical disorder affecting the brain, and it comes with physical symptoms as well.

So don't rush to call them lazy whiners. It might take their entire willpower to get out of bed and not cry in the morning.

They appreciate your help.

Do your best to support people who suffer from high-functioning depression, as it reminds them they're not alone.

A single word or simple action can make a huge difference for your depressed co-worker: text them, ask how they're doing, offer to do something for them, send a cute picture, etc.

A single word or simple action can make a huge difference for your depressed co-worker or friend.

Even if they seem indifferent, they're not.

When suffering from high-functioning depression, people go to great lengths to struggle with challenges and continue working efficiently.

They delegate tasks when appropriate, understand others depend on them and try hard to get through every five minutes of their life.

The biggest challenge for them is to figure out they have a problem, admit it, seek help and not ignore treatment.

Yes, treatment works.

Specific lifestyle habits, medical care and effective therapy help to live a full life, manage depression and recover from it.

Impossible is nothing for those who have found strengths to function in the workplace despite their condition.