My favourite definition of depression was defined by late psychologist, Rollo May. He defines it as "the inability to construct a future".There is no bigger liar in the whole wide world than depression.
It makes you believe negative things about yourself that are not true.
Every psychologically healthy human lives today in eager anticipation of tomorrow because our imagination tells us that there is something good waiting for us in the future. Many people get married today for the "happily ever after" of tomorrow. You get a great job today so that you can achieve all the things you have been dreaming of doing tomorrow. Even when the job is crappy today, your mind is set on tomorrow because you hope to get a better one.
There is something inside you that tells you consciously or subconsciously that you have the resource or you can pull together the resources to achieve your dreams eventually. This is what living is about. Animals do make plans for the future but humans are unique because we are able to plan far ahead. We are optimistic creatures by nature. Sometimes we don't realise this until we are hit by depression. This is when we become aware of how optimistic we had been and how important that state of mind is to our present and future.
When a person is depressed they lose optimism and get trapped in their negative and false interpretation of the present. This affects the way they visualise the future. They practically lose the ability to imagine a desirable future. Nothing seems worth fighting for because they only see an outcome that is undesirable.
The way out of this for a depressed person is not to take your feelings too seriously. Remember everytime you feel this way that your mind is only playing tricks on you. Do not wait for when you feel optimistic before you do things. Do things inspite of the fact that you feel pessimistic and hopeless. As long as you keep doing this, something will eventually work out and the rush of positive feeling will begin to return as a result. And this will help you get even more and more optimistic about the future. Of course, this easier said than done for a depressed person but it is an effective way of returning to your normal mental state.
This has often been my personal experience. May we always work to keep our abilities to construct a future.