The following three factors are considered to be the causes of depression.

• environmental
• biological
• genetic

A combination of these three factors can result in clinical depression, a severe depression disorder that can completely disrupt a person’s life.

Environment Factor:

Environmental factor includes, but are not limited to:

• Death of any loved one
• Loss of Job
• Business failure
• A nasty divorce
• Lack of fun
• Homelessness
• Poverty
• An unhealthy diet
• Lack of sleep

People suffering from depression due to any environmental factor are able to do the basic tasks in life. Depression caused by this factor usually lasts a determined time.

Biological Factor:

A change in the brain chemistry i.e. changes in important hormones are considered to be the biological factor that causes depression. An example of biological factor can be developing of postpartum depression by young mothers and pregnant women. Cortisol, a hormone that is produced in situations of fear, anxiety, or stress within the body is one hormone that is changed. However, researchers don’t have any scientific proof yet that it is the chemical imbalance in the brain that causes the depression. There is a possibility that the depression causes the imbalance.

Genetic Factor:

Genetic factor implies family history of depression. If any one of the parents has had a depression history, odds are high that the child will also suffer from depression at some time in his life. If both parents have had a history, chances are much higher.

Other factors that can cause depression include:

• Side effects of certain medication
• Alcoholism
• Use of heroin
• A physical injury due to an accident
• Long-term diseases such as cancer
• Pessimism