What causes depression? I am only 28 years old and have been diagnosed with this disorder

While mild depression has a cause, both moderate and severe depression generally are complex brain disorders which are not well understood. Mild depression may be related to the environment, such as being unable to cope with the job, unemployment, financial problems or loss of a loved one. No one understands why severe depression occurs. Even though many brain imaging studies have been done, the exact neurotransmitters in the brain which play a role in depression are still in question. Some studies do show that severe depression may be more common in families. In most cases, the cause of depression is simply bad luck