An estimated 16 million U.S. adults had at least one major depressive episode in the past year, where their symptoms interfered with their ability to work, sleep, study, eat or enjoy life. Health groups across the country recently recognized National Depression Screening Day and, according to the National Institute of Mental Health , it's worth taking a moment to assess your mental state.

What is a depression screening?

This screening is a simple questionnaire that asks how often an individual experiences symptoms such as low self-esteem, poor appetite, lack of concentration and losing interest in things you enjoy. Screenings can be administered by most physicians and at community screening events, and they are available free online from organizations such as Mental Health America . Novant Health also has an online depression risk assessment .

Dr. Luis Betancourt of Novant Health Psychiatric Associates in Charlotte, North Carolina, wants people to know that they don’t need an official screening to get help. “If you’re having trouble, ask yourself these three questions: Do I feel helpless? Hopeless? Worthless? If the answer is ‘yes,’ it’s time to get some help, especially if those feelings are accompanied by any desire to physically harm yourself.”

Everyone goes through periods of feeling sad or down, but Betancourt explains that a major depressive episode overwhelms your life, affecting you “more days than not in most weeks, or persisting for more than a month.”

Who should be screened?

Some primary care physicians are incorporating depression screenings into routine appointments, especially for patients with chronic conditions. Depression can often occur in patients with heart disease, stroke, cancer, HIV/AIDS, diabetes and Parkinson’s. Studies published in the Journal of Psychosomatic Research in 2002 showed that patients with comorbid depression tend to have more severe symptoms of both depression and the medical illness, more difficulty adapting to their medical condition and higher medical costs than those who do not have coexisting depression.

“Depression and other illnesses tend to go hand in hand,” Betancourt said. “When one gets worse, the other often does, too, and the outcomes can be very bad. But research shows it can also work the other way. If you treat your depression, other complications can improve.”

How to get help

If you or someone close to you is experiencing a major depressive episode, seek help from someone you trust. “If you think you’re depressed, that’s a good enough indicator to get help," Betancourt said. "Talk to your doctor, a counselor or a clergy member who can connect you with the resources you need."

If you are thinking about harming yourself, or know someone who is, call 911 or go to a hospital emergency room immediately.

Other resources include the National Alliance on Mental Illness and the American Psychological Association .