Negative feelings of unhappiness, worry and frustration are experienced by everyone alive. We feel disappointment after a failure or sorrow after a separation or a loss.
Depression is a feeling that can occupy every one at some point in time. To be able to manage and overcome depression you need to first understand the causes of depression and overcoming this unhealthy emotion or thoughts.
These negative feelings are normal and do not affect significantly our ability to meet our daily obligations. You might even say that it is also useful to the extent that they help us to better understand some of our weaknesses.
When the grief instead of decreasing by time it becomes more intense and lasts more than two weeks, and hinders the normal activities of our life such as work, diet, sleep and our close relations, then it is likely that we suffer from depression and we need the help of a specialist to deal with it.
Sorrow can train us so that we can face adversity that may occur later in life in a dynamic way. The self-knowledge arising from the negative experiences helps us to make the effort to change ourselves in order to avoid future negative consequences of immature behavior.
The main defining characteristic of depression is not the presence of negative feelings, but the intensity of the severity and the length of time involved.
To understand depression all the more, let us find out the different symptoms that a person can experience when he or she has depression. Here are they:

1. Reduction of interest or pleasure in all or almost all activities
2. Sometimes thoughts about death and suicide
3. Stress, anxiety, indecision
4. Loss of energy and exhaustion
5. More or less appetite for food
6. Moodiness, for the most part of a day almost every day
7. Trends isolation, social withdrawal
8. Frustration, indifference
9. More or less sleep
10. Continuing grief
11. Loss of interest in the search for erotic partner or for sex.
12. Concerns and pessimism for the future.
13. Feelings of guilt