Unipolar major depression does change the way you think, and understanding these changes can help you return your mind to its nondepressed state. For example, unipolar major depression can make you continue to think on and on about a problem until you have made a mountain out of a molehill. Your thinking is biased toward the negative, and the more you think, the more negative your thoughts become. For example, you might start watching a beautiful lake that elicits calm, peaceful thoughts. However, if you go on to think too much, you realize that the lake could be polluted, that it could carry disease, that it could overflow and kill everyone in the surrounding area. Depression has made you think too far in a negative direction until you turned a peaceful lake into a national disaster.
In addition, the negative thoughts of depression may intrude into your consciousness and repeat themselves like a broken record. Out of nowhere, your mind is drawn to your saddest, most negative memories. Long-gone memories of losses, failures, and disappointments are dredged up, and it feels like you are being forced to experience them all over again. For example, you might be working happily or watching an enjoyable film when you are suddenly distracted by lucid memories of the funeral of a loved one that you attended as a child but had not thought about for years.
In unipolar major depression, negative thoughts gradually crowd out happy thoughts until only the dark ones are left. Even if you start out with bright, positive thoughts, your depression can turn them around until you are focused on past failures, inadequacies, social faux pas, and thoughts of worthlessness. These intrusive negative thoughts can become so severe that you are convinced that you are a hopelessly flawed person who does not deserve to be happy.
If this is you, you need to go to a doctor to see if you have unipolar major depression. If you have it, you should begin appropriate treatment right away. As your depression improves with treatment, you will realize that you are really a nice person doing your best to keep afloat in the face of a serious disease, and soon you will not be able to find these dark thoughts anymore.