Just about every successful person under the sun advises others to work doing what they love. So there's good evidence we have this concept that work can be (dare I say it?) fun. That it can make us happy. And yet, here we are, with the Employers Health Coalition asserting that almost one in four workers (23 percent) admits to having been diagnosed with depression at some point in their lives.

Why are so many of us so sad?

1. You don't get a chance to be yourself.

Despite the current emphasis on authenticity, It can be tough to let your guard down and make friends in the face of agenda and protocol, especially if you are the boss who has to portray some semblance of authority. This said, most workers put in more than 40 hours a week, either because they need the cash or because they're afraid they won't get ahead if they don't. That's a lot of time every day faking it.

2. Your pay undermines your sense of self-worth.

In the United States, we tend to link the ideas of value, time, skill and intelligence. If we can apply a specific knowledge or skill set, for instance, then others usually see our time as more valuable and our pay rate is higher. Subsequently, we feel like we are worth a great deal and have an important role in the community. But with wages stagnating and the job market becoming increasingly competitive, you might have trouble rectifying your expectations and sense of self with financial reality.

3. You have little or no control.

Work usually means doing what someone else tells you, when they tell you to do it, with their tools, according to their timeline. There can be significant hurdles to get higher levels of management to hear concerns, too. This lack of control can give the illusion of total powerlessness, which feels demeaning.

But don't think that you're in the clear just because you call the shots, either. If you're the boss, you might feel like you're at the mercy of your stockholders, suppliers or others in your operational network. That feeling quickly can worsen when an unexpected factor gets thrown into deals that are worth thousands or even millions of dollars, or when money problems force you to make tough calls you know people will hate.

 4. You don't have your own sense of direction.

The majority of people go into jobs because they have others telling them they'd be good at those positions, or because those positions enable the individuals to meet specific financial or other obligations. Without the purpose of the work matching your own passion, it's hard to get revved up about going into the office.

5. The company sees things differently than you do.

While thousands of companies play by the rules, others have ethical standards that would make a fox in a henhouse look tame. You might get depressed and overwhelmed with guilt if you have to go to work every day with your values constantly clashing with what leaders say they want from you.

6. You have conflicting priorities.

Work can be depressing if it's routinely pulling away from something else you see as genuinely important. For example, if you are a parent, you might feel guilty when you work hard for your career because you know you aren't there as much for your kids. The big clue this is a problem? You always feel angry that there's not enough time to get to all your interests.

7. The work doesn't fit your personality.

Just because you have a talent or aptitude for something doesn't mean it's an ideal fit for your personality. For example, you might be ridiculously good at communicating with others face to face but feel drained when you do it because you're more of an introvert.

8. The environment is a mess.

Lighting, the presence of plants or animals, the chance for privacy, the availability of something healthy to eat, a lack of personalized space--it all can affect mood and the way you perceive your job.

How do we combat workplace blues?

There's no magic pill for the workplace blahs. (Sorry. I'm a realist. I have to be honest here.) But if you need a basic approach, tell depression to STOP.

Speak up--Tell someone how you're feeling so they can offer empathy and support. That someone doesn't have to be your boss. But the majority of employers understand that it is beneficial to productivity and the bottom line to invest in you getting help, and 64 percent say they'd refer an employee to an EAP professional! A formal disclosure also can help you get reasonable accommodations under the Americans with Disabilities Act.

Take time to analyze--Who are you? What are your goals? When are you happiest or saddest? Why? What would change look like, and what physical and human resources do you have to achieve it?

Organize yourself--It's not just about physical order and control here, although that matters. It's about using your analysis to set yourself up to easily transition from where you are to what you want.

Pay it forward--Once you've made changes for yourself and gotten some help, be open to help others who need you. Giving back is a fabulous way to make a difference and feel continued relevance.