Depression is a feeling that we get when something bad happens and we are unable to deal with it. Even though depression is now known to have serious effects if it persists for a long length of time, the actual causes of depression are not well defined. There are some theories that suggest a multiple number of reasons, both internal and external factors which can cause depression. There are other theories about the cause of depression arising from genetics. With this theory the family and their behavior has a predisposition towards depression. There are numerous studies and research that has shown family members who are affected by depression have a genetic makeup that is very different from family members who are unaffected by depression. It has been noted that changes in the brain structure or even brain functions may be one of the causes of depression. While there is no clear evidence of brain functionality or genetics as being predisposed towards depression, there is ample research data to suggest that this is the case. Low self esteem and pessimism are thought to be the other causes of depression. With these mood traits a person suffering from low self esteem will regard themselves with feelings of pessimism, worthlessness, a desire to end their life and perhaps even attempts at suicide. In this case the person who suffers from low self esteem and depression will only see the negative aspects of life. These low self esteem and pessimistic feelings maybe some of the causes of depression, as they invoke the response towards depression. Being overwhelmed by stress can easily lead a person into a state of depression. The many pressures that we face in our lives and the great expectations that are placed on us contribute to this feeling of stress. Therefore as more stress enters our lives depression begins to set in. Low self esteem, pessimism and stress are considered to be psychological causes of depression. Other causes of depression can include any physical changes that occur to our bodies. Severe medical conditions like Parkinson’s disease, heart attacks, strokes and diabetes can make the individual believe that there is nothing worthwhile living for. This emotional state in many cases causes the person to drop into a depression phase. By feeling depressed the rate of recovery is delayed. While it is not completely clear what the exact causes of depression are, there is agreement that certain physical, emotional, and genetic traits can lead towards depression. Whatever the actual cause is, the end result is that the individual who is suffering from depression has a very poor quality of life. Therefore until we can define what are the real causes of depression, all that we can do is to help them become better.