D epression is quite broadly thought of as an illness. For some people, it is. They need psychotherapy and/or antidepressant medication.

For many more of us, however, feeling blue is -- at least in part -- a habit. Or, more precisely, a set of habitual ways of thinking and feeling.

Here are nine strategies for breaking the habit...

UNDERSTAND YOUR MOODS

Many depressed people behave as if black moods show up for no apparent reason. This false belief intensifies the misery by causing feelings of hopelessness and helplessness.

Misery does not strike from out of the blue. There’s usually a trigger -- some disappointment, a setback or a loss of some kind. You will feel better if you can identify the trigger.

Next time you feel down, consider why. Keep a journal in which you detail your mood shifts... and your thoughts as to what may have triggered them.

COMMUNICATE YOUR FEELINGS

Ironically, a leading cause of depression is failing to acknowledge painful emotions. “Unfelt” feelings do not wither away. They merely leave you feeling numb... or filled with dread.

Learning to “feel your feelings” is easier said than done. One good way to start is to become alert to brief flashes of feelings that you do have.

Also important: Tell the people around you how you feel, and fight your impulse to mask “unacceptable” emotions.

CHALLENGE YOUR THOUGHTS

It goes without saying that depressed people are pessimistic. They assume that any good fortune they experience is the result of blind luck. Meanwhile, they take full blame for bad luck and assume that its effects will be catastrophic and long-lasting.

These assumptions are a self-fulfilling prophecy. If you assume that things will turn out badly, you’ll see little value in preparation or perseverance. Of course, these are keys to success in any endeavor.

Always subject your pessimistic thoughts to rational analysis. If you tend to think nothing ever works out for you, challenge that notion by recalling occasions on which things did turn out well.

BARGAIN WITH YOURSELF

If you dread doing a task, promise that you’ll reward yourself for making a start -- and sticking with it for 30 minutes. You might treat yourself to a short walk, a computer game, etc.

SET PRIORITIES

If you’re feeling overwhelmed by all your responsibilities, make a list of all the tasks you need to accomplish. Then rank them in order of importance. Focus only on the priorities.

HAVE REALISTIC EXPECTATIONS

Depressed people often harbor a secret fantasy that they can be “cured” by the love of people around them. This unrealistic idea puts enormous pressure on relationships. It sets the stage for deeper depression, too, as the continuing inability of your loved ones to cure you leaves you feeling continually disappointed.

Loved ones provide valuable support, of course. But meaningful change must come from within. Acknowledge this.

BE GENEROUS

Reaching out to those in need does more than offer a distraction from your own negative feelings. It fosters self-esteem by demonstrating to you that you do have something of value to offer.

PURSUE PLEASURE

If you’re depressed, it’s important to continue to participate in activities even if you would prefer not to. Don’t wait until you’re in the mood. Simply schedule activities that you once enjoyed -- reading, walking, etc.

In addition to being pleasurable, exercise causes the brain to produce endorphins. These natural compounds elevate the mood for hours.

LOOK FOR HEROES

Many great people struggled with depression, including Abraham Lincoln, Eleanor Roosevelt and Winston Churchill. If you’re feeling down, reading biographies of these great people could serve as the perfect antidote.