Just because you think negative thoughts doesn't mean you are depressed or you have a problem with depression.  You may simply be a pessimist who looks at the cup of life as always being half empty rather than half full.  There are millions of non-depressed people who have a pessimistic view of life, but never develop the twisted thoughts and distorted emotions found in depression.  They have a stable consistently pessimistic outlook, but they don't exaggerate their difficulties or slip into dark self-destructive moods that tell them life isn't worth living.  They know life is worth living, but they tend to focus on the negative.  They frequently overlook and ignore good things when they happen.

If you are feeling down and depressed, you may wonder whether you have a problem with clinical depression, or if you need to be on medication.  It's easy to pop a pill into your mouth with the hope that your negative thoughts will disappear.  The result is there are thousands of people taking antidepressants who don't need them, and many of these people don't realize that altering the chemistry of their brain isn't something you do lightly.  There are real complications associated with using antidepressants, and you shouldn't tinker with your brain chemistry unless it's the only way to deal with problems.

The majority of people who have a problem with negative and depressing thoughts don't have a problem with clinical depression.  Their brain chemistry is fine.  Their problem is they are living a toxic lifestyle that has taken a toll on their mind.  They are mentally exhausted, and if they would change the way they live, their negative feelings would disappear.  So let's take a look at some of the different states of mind that could make you wonder if you have a problem with depression.

Five states of mind are commonly associated with negative thoughts.

1.  Fatigued state.

2.  Overloaded state.

3.  Habitually negative state (the pessimist)

4.  Mild to moderate mood disorders. 

5.  Clinical depression.

All people experience the negativity associated with a fatigued mind.  Most people intermittently experience the negativity associated with an overloaded mind.  A few people live with a habitually negative mind; although they are not clinically depressed, they tend to focus on the dark side of life out of habit, but they never lose command and control of their thoughts.  These first three states of mind are not illnesses.  They frequently are the results of living a toxic lifestyle that has spiraled out of control.  Habitually negative thinkers demonstrate a high tolerance for negative thinking, and they may be able to muddle through their lives without ever developing clinically significant depression.  These states contrast sharply with significant mood disorders and clinical depression, which are illnesses that require treatment by a physician.

Excerpt from :

Zero Tolerance To Negative Thinking : Good-by Depression - Hello Positive Mind

David J Abbott M.D.