We all grew up with Robin Williams.

For me, it began with Mork & Mindy in the late 1970s and early 1980s, and continued with the angsty teen drama The Dead Poets Society. Then it was back to laughing with Aladdin, and I'm looking forward to watching the upcoming Night at the Museum: Secret of the Tomb with my children. Unfortunately, Williams's brilliant career came to an abrupt end last night when he died, in an apparent suicide.

If you Google Robin Williams genius, you get more than eight million hits, because that is what he was. A genius. So are many entrepreneurs. Additionally, geniuses want geniuses working for them, and so the startup community is filled with people with ideas exploding out of their minds. It's a fantastic bunch of people to work with, but like Williams's comedic genius, there can be a side to it that is anything but funny.

People have long thought that there is a correlation between intelligence and mental illness, and especially between creativity and mental illness. Nancy Andreasen, M.D., Ph.D., studied writers from the prestigious Iowa Writers' Workshop. This is one of the top, if not the top, writing programs in America, producing 17 Pulitzer Prize winners and six U.S. poet laureates. She said:

Many definitely had experienced periods of significant mood disorder. Importantly, though handicapping creativity when they occurred, these periods of mood disorder were not permanent or long-lived. In some instances, they may even have provided powerful material upon which the writer could later draw, as a Wordsworthian "emotion recollected in tranquility."

Inc.'s own Jessica Bruder chronicled mental illness in startups in her award winning story "The Psychological Price of Entrepreneurship." She detailed how numerous entrepreneurial people plunged into depression. She quotes John Gartner, a psychologist who has studied entrepreneurs and "hypomania." What is hypomania? Gartner explains:

If you're manic, you think you're Jesus. If you're hypomanic, you think you're God's gift to technology investing. We're talking about different levels of grandiosity but the same symptoms.

The thing is, this is very common in the startup world. You have to think you're better than others in order to be willing to make the very scary jump into starting your own business. Otherwise, you would never be willing to take that risk. Bruder explains that people with these characteristics are at higher risk for depression. Failure can make it even worse.

So, what can you do--not only to protect yourself and your family but to protect your employees, who may also have some of these problems? Here are a few ideas:

1. Be aware that mental illness is real.

It's not just being sad or being different. It affects actual brain chemistry. You didn't cause it, and it's not a moral failing. Help is possible.

2. Invest in an Employee Assistance Program.

With an EAP, an employee who is struggling can call and speak with someone who can either help or direct the employee to help. The cost can be extremely low, less than $50 per year per employee. This can be invaluable to an employee who needs it.

3. Don't fight against disability accommodations.

The Americans With Disabilities Act gives some protections to people suffering from mental illnesses (and physical ones as well). The law simply requires "reasonable accommodations." Some employers try to make reasonable requests seem as unreasonable as possible in order to not have to make accommodations. Don't do this. Be reasonable. And if you are the one suffering, remember to make a reasonable accommodation for yourself.

4. Make your employees aware of the signs of depression.

The first step to getting help is recognizing that you need help. Consider a lunch-and-learn about depression in the work force, or hanging a poster in the break room.

5. Don't punish someone for getting help.

If your business has fewer than 50 people, you may not have to hold a job for someone who needs to take time off for mental health issues. (You may have to, as it may be considered a reasonable accommodation under ADA, which takes effect at 15 people.) Just because you don't have to, it doesn't mean you shouldn't. If someone needs help, don't be an impediment to his or her getting help.

In any given year, 6.7 percent of the population, age 15 to 44, are suffering from depression. This means there's a good chance someone in your office is. Do what you can to alleviate this burden, especially on yourself.