Sometimes a job is just a job, but for most people it's more. It's our second home and often provides our second family. It can be either the provider or the destroyer of our self-worth. We define ourselves to a great extent by our work - after all, what is one of the first questions we are asked when we meet someone new? "What do you do?"
Despite the large part that our work plays in our lives, there is a surprisingly small amount written about how to cope with depression at work. Many more articles and books focus on how depression affects our personal lives. Out of all the books on depression, only one, Working in the Dark: Keeping Your Job While Dealing with Depression, by Fawn Fitter and Beth Gulas, deals exclusively with depression at work.
When I was going through bout after bout of major depression, there was one thing I was thankful for. For some reason, I was able to keep myself together at work and not collapse until I got home. I'm not sure why - maybe because work generally invigorates me and it gave me something to focus on.
But for many people with depression, working while depressed is a Sisyphean task. They can barely drag themselves to work every day, let alone perform well. If you work in an office, you might often just sit and just stare at your computer. If you're in the service industry, you may find that you're snapping at customers. Maybe you're having trouble concentrating, which in certain jobs, like construction or operating machinery, can be disastrous. You know that if you go on like this you will very possibly lose your job.
That's something you want to avoid at all costs. Even if you are for some reason financially able to weather losing your job, that gap in employment will haunt you for years. I lost my job due to my Multiple Sclerosis, and found it very difficult to explain why I left that job without disclosing my MS or outright lying.
There are two avenues you can follow in this situation: you either disclose your condition at work or you don't. In either circumstance, you should get treatment for depression, of course, if you aren't already.
Reasons not to disclose
I've always been fairly open about my depression at work, which very possibly was not a bright thing to do. In many cases I've seen a distinct chilling in someone's attitude towards me after my disclosure. In some cases co-workers have taken it in stride, and in rare cases, someone has responded by disclosing their own depression or that of someone they know.
You are always running a risk when you disclose your depression to anyone at work. You may feel that if you've comfortably discussed details of your love life with a co-worker or co-workers, you should be able to discuss anything.
Don't count on it. Mental illness falls into a whole new category of true confessions. The subject is still taboo, and is still misunderstood by many people who haven't had a friend or family member who has a mental illness. There is no doubt that it could affect your potential for advancement.
On the other hand, your perception of your performance may not be accurate due to your depression. I went through a major bout of depression right before I was diagnosed and treated. When I had my next performance review, which was positive, I asked my boss, who was very exacting, if she had been aware that I was suffering from depression. She had no idea.
Some work cultures are more difficult, if not impossible, in which to disclose your mental illness. I have received several heartbreaking emails over the years from people in the U.S. military who were afraid to even seek treatment for their depression, even from a non-military doctor, for fear that they would be exposed somehow. I'm sure they were right to be concerned.
Reasons you should disclose
One guideline is to be open only when it would be worse to keep quiet. In other words, if it's clear that your performance has suffered and you are afraid that you are going to be fired, you need to disclose your condition. As I understand it, bringing your condition up when you are in the process of being fired won't protect you, because you didn't give your company the opportunity to accommodate your condition. The ADA requires employers to make accommodation to an employee with a "known condition."
Another reason you might want to disclose your depression is if you know of another employee who disclosed that they are mentally ill and were treated fairly. In this situation, it's better that your employer know than letting them think that you are simply a poor performer.
As you can see, the decision of whether to disclose your depression or not is complicated, and each situation is different. I would definitely recommend getting Working in the Dark: Keeping Your Job While Dealing with Depression, as it has some useful tools to help you make this decision. Also, I would strongly suggest your consulting an employment lawyer, if you can afford it.