Ebeneezer Scrooge definitely wasn't a lot of fun to be around during the holidays. But there's a big difference between just being grumpy and being depressed, says Dr. Dan Christensen, and it's important to know the difference between the two.

Concerned friends and loved ones should be on the lookout for signs of serious emotional distress that might be masked by "bah hum-bugs," says Christensen, medical director and depression expert at The Western Institute, a psychiatric hospital clinically managed by the University of Utah's Health Sciences Department of Psychiatry.Not that you are necessarily either grumpy or depressed if you choose not to celebrate Christmas. Perfectly healthy reasons exist for not celebrating, he says. "Those who seem to disdain the frenetic nature of the holidays may, in fact, be wiser or less responsive to social pressures."

But if you suspect that a friend, family member - or you yourself - may be depressed during the holidays, Christensen suggests looking over the following depression checklist. You can compare your responses to Scrooge's.

- A LOSS OF INTEREST IN THINGS ONCE ENJOYED: If Scrooge had suddenly lost all interest in his counting house and that lack of interest lingered on, then he might be depressed, says Christensen.

Instead, Scrooge's loss of interest in some of the things that motivated him early in life - his boyhood idealism - was more a long-term change of goals.

- INABILITY TO CONCENTRATE OR THINK: Depressed people have disordered thoughts and/or difficulty concentrating over a period of weeks or months. That's different from having a few bizarre thoughts, or even seeing Marley's face on your door knocker.

Dickens' book, says Christensen, does not provide sufficient data to determine whether Scrooge had an ongoing problem with concentration or was just having a bad day.

- RECURRING THOUGHTS OF DEATH OR SUICIDE: Scrooge was haunted about death and a tormented afterlife, but he didn't wish to die. "Depressed people feel there is little reason to continue living or that life feels too painful for them," says Christensen.

- OVERWHELMING FEELINGS OF SADNESS OR HOPELESSNESS: Scrooge was definitely sad and even sobbed when confronted with bad memories. But that's normal, says Christensen. In addition, Scrooge was able to respond happily to joyful memories.

"Depressed people, often `stuck' in a sad or hopeless state, find it all but impossible to react to positive events," says Christensen.

- SLEEP TOO MUCH OR NOT AT ALL: Scrooge slept for about 24 hours straight, but Christensen says he would suspect depression only if Scrooge continued this sleep pattern over a period of more than two or three weeks, or if his dreams so disturbed him that he could not sleep at all.

- NOTICEABLE CHANGES IN EATING HABITS: A surprising number of older people commit suicide by refusing to eat or care for themselves, says Christensen. But then older people also eat less even when they are not depressed, "which poses a challenge in evaluating the eating patterns of older people within the context of depression."

Scrooge was definitely in a high-risk age group for depression, Christensen notes. "His isolation and eating patterns should have been monitored by his nephew." On the other hand, Scrooge had been this way for years.

- LOSS OF ENERGY AND FATIGUE: Depressed people find it hard to work up energy for anything. Scrooge, on the other hand, worked as hard as anyone and didn't even want to take a day off for Christmas.

- FEELINGS OF WORTHLESSNESS AND GUILT: At the end of "A Christmas Carol," Scrooge felt ashamed about his behavior. In contrast, says Christensen, "depressed people feel worthless in the face of no evidence or evidence they distort."

Unlike Scrooge, a depressed person cannot "fix" his feelings of sadness or regret, says Christensen, who recommends that anyone suffering from depression be evaluated by a professional.