Everyone experiences variations in mood -- transitory blues, disappointments, the normal grief that accompanies the loss of someone you love. But a severe or prolonged depression that interferes with the ability to function, feel pleasure, or maintain interest is not a mere case of the blues. It is an illness. Researchers have demonstrated that it results from biochemical imbalances in the brain.

Depressive Illness, also referred to as Affective or Mood Disorder, attacks millions of Americans and is often fatal; yet few people are being properly treated or even diagnosed. The costs of this neglect, both in terms of human suffering and economic loss, are staggering.

Depressive Illness is among the most common and destructive of illnesses prevalent in the United States today. In addition to major depression, many people suffer from manic depressive illness (bipolar disorder) which is characterized by radical mood swings from severe depression to exaggerated, inappropriate elation.

An estimated 35-40 million Americans living today will suffer from major Depressive Illness during their lives. For each person directly suffering, three or four times that number of their relatives, employees, associates, and friends will also be adversely affected.

Of those 35-40 million afflicted, a substantial percentage will commit suicide if not treated with appropriate medication.

In terms of human suffering, the consequences of untreated depression are beyond measure. They include loss of self-esteem, "self-medication" with alcohol and drugs, family and career disruption, chronic disability and, in many cases, death. Suicide is now the second leading cause of death among children and adolescents.

Those Who Suffer Blame Themselves

Even among those suffering from Depressive Illness, most do not know they have a treatable illness. Most blame themselves and are blamed by others. This leads to the alienation of family and friends who, if they knew of the illness, would be likely to offer support and help find effective treatment.

There Are Several Causes of Depressive Illness

There are probably several causes of Depressive Illness and several different types of depression. Recent research shows that depression runs in families. The most severe form, bipolar disorder, is most likely inherited.

Certain environmental situations, such as stress or breakup of important attachments, may precipitate depression, especially in vulnerable persons.

Research is underway to understand the interaction of genes and environment, and precisely what is inherited.

Symptoms of Depression and Manic Depression

The symptoms of Depressive Illness are highly recognizable, both to those affected and to those closest to them, once they are told what to look for.

Here is a checklist of symptoms of Depressive illness:

• Loss of energy and interest.
• Diminished ability to enjoy oneself.
• Decreased -- or increased -- sleeping or appetite.
• Difficulty in concentrating; indecisiveness; slowed or fuzzy thinking.
• Exaggerated feelings of sadness, hopelessness, or anxiety.
• Feelings of worthlessness.
• Recurring thoughts about death and suicide.

If most of these symptoms last for two weeks or more, you probably have Depressive Illness. Sometimes depression alternates with "mania" and is called Manic-Depressive Illness.

Manic Depression causes mood swings creating periods with the following symptoms:

• A high energy level with decreased need for sleep.
• Unwarranted or exaggerated belief in one's own ability.
• Extreme irritability.
• Rapid, unpredictable emotional change.
• Impulsive, thoughtless activity, with a high risk of damaging consequences (i.e., stock speculations, sudden love affairs, etc.).