We've made years of progress with the Americans with Disabilities Act (ADA) since it was enacted 24 years ago, though not all people protected by the law know about their rights. Luckily, the new pregnancy discrimination federal guidelines released just last week highlight protection for pregnant employees under the Pregnancy Discrimination Act of 1978 (PDA) and the ADA.

Still, a serious disability often overlooked in the workplace that affects many new moms and dads is postpartum depression.

Shortly after Brooke Shields gave birth to her daughter, Rowan, she began to have thoughts of suicide instead of feeling of joy. She even remembers having visions of her baby being thrown through the air (not by her), hitting the wall, and sliding down it. She cared little if the baby cried, and recalls remarking to her husband in a deadpan, "Yes, she's crying. Wonder what she wants."

Now imagine what this would be like if you had to go to work the next morning.

Luckily, Shields is a famous actress who didn't need to worry about making a living, but for millions of American women postpartum depression doesn't just effect their personal lives, but their professional lives too.

Sadly, this is the reality many new moms suffering from postpartum depression face. Lacking paid maternity leave and unable to go without a paycheck, they head back into the trenches shortly after giving birth suffering from a true disease that often is temporary, but downright debilitating. Imagine further that at work is a boss who would like nothing better than to replace what he sees has a liability (you) with a 25-year-old man whose only interest outside of work is his Xbox.

This situation is further complicated by the fact that women who suffer from postpartum depression and ask for time off are in a double bind. They may just be returning from maternity leave and now require more time off or a reduced schedule to address the depression. The temptation here is clearly high for a manager, looking at the short term, wanting to fire an employee seen as a liability.

Postpartum depression remains a serious problem with some studies suggesting that as many as 1 in 10 women will experience a major depressive episode either during or after pregnancy. And this does not fully capture the problem, as some women experience a mental health disease that cannot be easily categorized as postpartum depression - for instance, many women experience postpartum OCD/anxiety, characterized by, among other symptoms, excessive hand washing and checking the baby.

Further, as women continue to close the gap in terms of workplace participation and pay, postpartum depression and related mental illnesses will have an even larger economic impact on families.

Surprisingly, men also suffer from postpartum depression. A 2010 study in the Journal of the American Medical Association shows that as many as 10 percent of American men suffer from a depressive episode between the birth of a child and their first birthday.

The study noted this was a significant public health concern that is often undertreated given that practitioners often focus on the mother without even considering that the father may also suffer from depression.

The cause of this depression may be that men experience hormonal changes that mirror those taking place in the body of the mother. Authors of the report concluded, "This suggests that paternal prenatal and postpartum depression represents a significant public health concern."

Protection Offered by the Americans with Disabilities Act

Fortunately, a woman or man in this situation may have some protection through the ADA, though sadly few people know about it.

Many people think of those suffering from permanent disabilities when they think of this law, such as someone confined to a wheelchair, for instance. But the law actually covers anyone with a condition that affects a major life activity. This includes include depression.

In fact, Congress recently amended the Act so that it covers more individuals and many more disabilities, even temporary disabilities like, depression and anxiety. The Equal Employment Opportunity Commission recently sued an employer that fired an employee suffering from postpartum depression. The case settled before trial.

What does this mean for someone struggling with postpartum depression? First, it means that their employer cannot fire them simply because they have a mental illness. Second, employers are often required to provide employees covered by the ADA with workplace changes that allow them to continue to work. These changes might include a quieter work place, more frequent breaks, or even time off from work.

But here's one catch, the ADA only applies to employers with 15 or more employees. (You can add the employees together if it is a joint employer - that is, two separate companies with the same ownership and management.)

What if you work for a smaller company? You are not covered by the ADA so, strangely, it may not be a violation of federal law for your company to fire you for suffering from depression. Still, some states have laws that provide workplace protections. In fact, sometimes the state laws provide more protection that the ADA itself.

And here's another catch for pregnant women. The ADA does not automatically apply to a woman with a normal pregnancy. Pregnancy alone is not a disability; though a pregnant woman experiencing a normal pregnancy is covered by the PDA if they work for an employer with 15 or more employees.

The distinction is important. The PDA protects women from discrimination based on pregnancy. The PDA, some courts have found, does not require an employer to provide changes to the workplace to address pregnancy related conditions. To be covered by the ADA, a pregnant woman needs to suffer from a condition that is covered by the Act. These might include anything from a woman experiencing a high-risk pregnancy that requires bed rest, to a woman experiencing gestational diabetes. It also would include a woman (or man) suffering from postpartum depression or a related mental condition, in many cases even if the condition is temporary or controlled by medication.

Here are a few tips for protecting yourself in the workplace if you are suffering from postpartum depression:

• Recognize that you may be depressed.

Having a new baby is thrilling, but difficult for anyone. About 1 in 10 women postpartum will suffer from clinical depression. Man men are affected too.

• See a doctor.

This is a crucial step to determine if you are protected under the ADA. Your doctor who can tell you if you have a mental illness, even a temporary one, like postpartum depression. And when you see your doctor, resist the urge to make it look like everything is okay. If you are depressed, tell him or her.

• Tell your employer in writing if you have a disability, even if you are not requesting a change at work.

Your employer is not bound by the ADA if it does not even know that you suffer from a disability. If you are not on record as giving your boss notice, you may not be protected if your employer later tries to fire you. Note that you are better off doing this with backing from a doctor, but this is not required, at least initially. If you think you are going to be fired due to the effects of what you believe to be depression, tell human resources or your boss what is going on. Then follow up by seeing a doctor.

• Request changes at work if you need them to help you function.

For instance, a quieter workspace, time to see your doctor, or time off from work. Know that in most instances your employer is required to make a good-faith effort to accommodate your disability. That means it is usually a violation of the Act to simply deny your quest.

• See a lawyer.

Yes, I know, you expect this coming from a lawyer, but it is in your best interest. The ADA is a very complicated law and you will be better off if you can have someone on your side who understands it. You can bet that your employer will call its lawyer if things get complicated.

Know, too, that the ADA protects someone "perceived" as disabled. So, even if you are not depressed, but you get fired or demoted because your employer thinks you are, you may be protected under the Act.

For instance, let's suppose your boss calls you in and says that he is terribly sorry, but the company is letting you go because it just cannot afford to have someone working while suffering from postpartum depression. But you are, in fact, not depressed. You are still covered by the Act because your employer that has 15 or more employees perceives that you are depressed and is firing you because of it. Note that this scenario may also constitute a violation of another federal law that makes it unlawful to penalize an employee based on caregiver stereotypes.

Do your best not to let shame keep you from protecting yourself. Mental illness, like postpartum depression, is real and can have dire effects on your work performance and personal life.

Apply any laws you can to protect yourself, such as the ADA. We've come a long way since it was enacted 24 years ago. Use it to your advantage.

Tom Spiggle is author of "You're Pregnant? You're Fired: Protecting Mothers, Fathers, and Other Caregivers in the Workplace" which will hit shelves later this summer. He is founder of the Spiggle Law Firm based in Arlington, Va., where he focuses on workplace law specializing in helping clients facing discrimination due to pregnancy or other family-care issues, such as caring for a sick child or elderly parent. This is Spiggle's first book. To learn more, visit: http://www.yourepregnantyourefired.com.