People who find they suffer from depression begin to notice that there are symptoms relating to depression. Not all individuals who suffer from depression recognize that they have a problem. There is no blood test for individuals to understand that they have a psychological disorder. It is not a disease, but a disorder that can be treated once it is recognized.

Symptoms of depression include constant sadness, irritability, hopelessness, trouble sleeping, fatigue, or feelings of worthlessness. There are levels to depression. A person may feel depressed due to a situation or it could be a constant mood. Major depressive disorder is when five of the symptoms listed appear for a prolonged period of time. Those who are depressed for a couple of days typically do not suffer from clinical depression.