Still, Dr. Saltz says the act will only last so long. "You can put on a face for a certain period of time while you're mild to moderately depressed," she says. "When you are severely depressed, you cannot. You really stop functioning."
Many factors can contribute to depression, Dr. Saltz says. "A traumatic event or very stressful event can trigger a depression, although depression also is genetically passed on, potentially, and some people have a depression without a stressful event happening."
Dr. Saltz says there's a big difference between feeling sad and being depressed. "Sadness is a normal human emotion that everybody feels and everybody should feel. It's healthy. It's part of the intricate fabric of emotions that we feel," Dr. Saltz says. "Depression is substantially different. You feel hopeless. Helpless. Worthless."
Women in particular often feel an overwhelming sense of guilt, Dr. Saltz says. "Guilt about everything and anything and things that are irrational—'I'm a bad person,'" she says. "In fact, when you go on to have severe, severe depression, which can become psychotic, you can have delusions [like], 'I am so bad that my insides are rotting. My brain is rotting."