Everyone feels blue once in a while. For people with depression, however, those feelings can become overwhelming.

It's normal to feel sad after a job loss, divorce or death in the family, but those feelings eventually wane.

With depression, however, feelings of sadness, hopelessness or despair last two weeks or more and interfere with people's day-to-day lives, such as their work, ability to sleep or even their interest in eating.

According to the National Institute of Mental Health, almost 15 million American adults suffer from major depressive disorder. More than 3 million others have mild or chronic depression.

Depression can affect people's physical health as well as their emotional well-being. Depression can lead to over-eating and other unhealthy behaviors, for example. Depression can also make it hard for people with chronic conditions like heart disease or diabetes to take care of themselves properly.

Depression may even contribute to physical diseases. In a 2007 study in the Archives of Internal Medicine , for example, women with even mild depression had less bone mass than other women, putting them at higher risk of osteoporosis.

Depression doesn't just affect individuals and their families. It also has a big impact on our economy. In fact, experts estimate that depression costs the nation more than $83 billion a year in direct medical costs, lost productivity in the workplace and expenses related to suicide.

Overcoming depression

A variety of strategies can help people recover from depression:

  • Individual therapy. Licensed psychologists or other mental health professionals can help people identify and solve the problems that contribute to their depression. They can also help them recognize and change distorted thinking patterns and problematic behaviors. And they can help people regain a sense of control and pleasure in life.
  • Marital or family therapy. Support from family and friends can help people with depression recover. But it can be painful to watch loved ones suffer. Marital or family therapy can help everyone who's affected by depression learn how to work together as a depression-fighting team.
  • Medication. Medication can be very helpful in reducing depression symptoms. Combining medication and psychotherapy usually works best. In fact, a 2005 literature review in the Journal of Clinical Psychiatry found that combining psychotherapy and medication boosted treatment effectiveness by as much as 75 percent.