There are many different types of depression that a person may end up suffering from, and each type of this illness can be caused from a variety of different factors. There are some people that simply have a chemical imbalance within the body’s system that causes them to suffer from this illness. In other cases the cause can be from a devastating event that has happened in the person life. Physical diseases or illnesses are often a problem that results in individuals becoming depressed, especially when the condition they suffer is long-term, and this is one of the most common forms of this particular illness. Stress and anxiety are also factors that can cause depression, especially in cases where it causes the individual to have problems with getting an adequate amount of sleep, which over a period of time can result in depression.