When German psychiatrist, Kurt Schneider, coined the term "depression" as a replacement for what was previously called melancholia, he unknowingly performed a spectacular disservice. The term, "depression," infers that you can merely cheer up to alleviate the disorder. We now know that depression is a chemical imbalance in the brain and, left untreated, can cause the brain to actually shrink in size and lead to permanent brain damage.
Depression is common. At any given time, 1 person in 11 will have depression. Depression is treatable with medication and up to 80% of those people find relief, yet only 27% seek treatment. Depression is a VERY SERIOUS condition, a potentially fatal disease - 1 in 29 will end their life in suicide, more common than deaths from Alzheimer's, homicide, arteriosclerosis, and hypertension. They are four times as likely to suffer a heart attack than people without a history of depression, and are at a significantly higher risk of death or a second heart attack.
In fact, prolonged sadness is but one of many symptoms which may or may not include changes in appetite and sleep patterns, irritability, anger, worry, agitation, anxiety, pessimism, indifference, loss of energy, persistent lethargy, feelings of guilt and worthlessness, inability to concentrate, indecisiveness, inability to take pleasure in former interests, social withdrawal, short-term memory loss, recurring thoughts of death or suicide, and in extreme cases, psychosis (hearing voices and/or seeing hallucinations) and physical pain.
People with depression benefit greatly from friends who say they are there for them and are willing to listen.
For more information about depression, consult the Depression and Bipolar Support Alliance website at http://www.dbsalliance.org.