Everyone gets depressed occasionally, but gloom should not be persistent in your life. Go to your doctor for a checkup. You might need medication or therapy.

I find myself thinking one sad thought after another and it makes me depressed. Is there anything I can do to stop this?
The cause of your depression could be a physical illness, life events, personality problems, side effects from drugs or combinations of these elements. Your doctor's choice of treatment — or no treatment — will be based upon symptom frequency and test results.

A flow of sad thoughts through your mind can be frustrating because you can't be sure if depression is making you think negatively, or thinking negatively is making you depressed. A common cold, exhaustion, stress, hunger, sleep deprivation, even allergies can make you depressed, which leads to negative thoughts.

In many cases, depression can be caused by negative thinking, itself. Our feelings follow what we are thinking, and dwelling upon negative thoughts can send us spiraling down into depression. This concept is the guiding principle behind Cognitive Behavior Therapy (CBT) developed in the 1960s by Dr. Aaron T. Beck at the University of Pennsylvania.

To combat negative thinking, it is important to understand it. The following are some cognitive distortions — ways that our mind convinces us of untruths. These distortions are usually used to reinforce negative thinking or emotions. By repeatedly refuting distortions, negative thinking will diminish.

Credit goes to David D. Burns, author of "Feeling Good: The New Mood Therapy" (HarperCollins, 1999), for coining common names for these distortions.

• Filtering: You dwell completely upon a dust speck you notice on a Van Gogh painting.  
• Polarized thinking: If you're not perfect, you're a failure. People are either wonderful or awful.
• Overgeneralization: You fell off the horse on your first try, therefore you will fall every time you get on a saddle.
• Jumping to Conclusions: Your friend hasn't called for a while, therefore she hates you. 
• Catastrophizing: Disaster is inevitable. You're obsessed with "What if? What if? What if?" 
• Personalization: Everything that happens is about you. Your best friend started playing tennis because he knows you don't like the game. 
• Control Fallacies: You feel like a helpless victim of external forces. Or, you feel personally responsible for everyone's happiness. 
• Fallacy of Fairness: You are the only one who knows what is fair, and you're sure that you are being treated unfairly. 
• Blaming: You blame others for your pain. Or, you blame yourself for everything. 
• Shoulds: There are rules that must be obeyed by everyone. If you violate the rules, you feel guilty. If others break the rules, you feel angry. 
• Emotional Reasoning: My emotions define the truth. I feel ugly, therefore I am ugly. 
• Fallacy of Change: You think you can change people to make yourself happy.
• Global Labeling: An extreme form of generalizing with exaggerated and emotionally loaded labels for yourself and others. You fail a quiz and call yourself a "lifetime loser."
• Always Being Right: Being wrong is not an option. You will do whatever it takes to win an argument.
• Heaven's Reward Fallacy: If you work hard and sacrifice, you will always be rewarded. If that reward doesn't come when you want it, you become angry and bitter. 

In our next column, we'll provide some techniques for accentuating the positive and eliminating the negative.

This article were first appeared on Live Science, you can read the original article here.