If you're depressed the symptoms pertain in a large way to your feelings. There's a tendency to think of this as psychological. You might say to yourself you have to "shake yourself out of it." Others might counsel "pull yourself together." But you hear of many people who just can't even get out of bed in the morning. This is why its an organic, medical disorder. But how can a biological cause be responsible for emotional manifestations in the mental realm? Its because brain chemistry is unbalanced which affects thinking and nerve functioning.
One of the characteristics is the persistence of the symptoms 24 hrs/day with no end in sight (not even a "light at the end of the tunnel"). One person said its like having the flu which never goes away--at least with a virus or germs the body will eventually heal. Even though the source is biological it has the result of affecting you emotionally because your thoughts monitor the predicament and your hope suffers because you can't visualize a solution. You feel hopeless. You, in effect, become helpless to figure out your own dilemma. This inadequacy leads to lack of confidence in yourself. You feel worthless. If you've always been a responsible person you may even begin to feel guilty. Then pessimism could be right around the corner. Pessimism is a tendency to look at everything negatively. One person commented that you become a different person. If your condition is chronic then its possible to lose sight of who you once were. Also, with your will power strained its possible to make bad decisions. If your behavior changes its good to get counseling so you don't go off in the wrong direction.