“I’m so depressed” might be the most overused phrase in our language. Even doctors may be too quick to make the diagnosis. Up to 25 percent of people currently defined as depressed may not be suffering from mental illness at all but are merely reacting normally to a stressful event, according to a 2007 study. It turns out that the American Psychiatric Association issued criteria that doctors use to diagnose clinical depression that don’t factor in why patients might be experiencing feelings of sadness. “The circumstances under which symptoms occur need to be taken into account during diagnosis,” says Michael B. First, M.D., a psychiatrist at Columbia University. If you experience a devastating event, how do you tell if you’re clinically depressed or just appropriately sad? “Ask yourself if the pain you’re feeling is in proportion to the severity of what happened. If you had a terrible argument with a friend and you’re not on speaking terms, feeling sadness for a few weeks is normal. But if you can’t get out of bed each day or focus at work, and you feel that way for many weeks or months, that reaction is out of kilter,” says Dr. First. If you’ve experienced either short-lived, intense sadness or you have been blue for longer than two months, seek help from a mental health professional. And if you’re not certain how you’re feeling, don’t wait. See a doctor. — Holly St. Lifer