by Sherry Torkos, B.Sc., Phm., and Jean-Yves Dionne, B.Sc., Phm.

The landscape of depression is colorless, flat, and endless. People who suffer from depression feel joyless and muted. Often, they can't even label the despair that tyrannizes them.

Depression strikes older people, sexual abuse survivors, alcoholics, those who grew up in alcoholic homes, people who are genetically predisposed to melancholy, people with serious physical illnesses, individuals mired in negative thinking, and many others. In fact, an estimated 17.4 million people in the United States suffer from depression. As philosopher Henry Thoreau said over a century ago, "The mass of men lead lives of quiet desperation"

Despite Thoreau's reference to men, women report depression twice as often. On the other hand, as psychotherapist Judy Hodel, M.S.W, C.I.S.W, of Green Bay, WI, says, "Maybe women are just more willing to seek help."

It is critical to distinguish between serious, clinical depression and garden-variety "blues." Sorrow, fear, anger, and guilt are all part of the human experience. Ordinary sadness is a rational response to disappointing external events.

Clinical depression, however, may be triggered by errant brain biochemistry and/or unresolved psychological issues. Hodel identifies clinical depression "by the duration and the intensity. If the person stops normal activities, if there’s a change in eating and sleeping patterns, if there’s a loss of interest in things that usually interested them, if it lasts longer that two weeks, it’s probably a major depression."

According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, depression is defined by the following set of standards:

Poor appetite and significant weight loss, or increased appetite and significant weight gain;

Insomnia, or increased sleep;

Agitation, or sluggishness in movement and thought;

Loss of interest or pleasure in usual activities, or decrease in sexual drive;

Fatigue and loss of energy;

Feelings of worthlessness, self-reproach, or excessive or inappropriate guilt;

Diminished ability to think or concentrate, or indecisiveness;

Recurrent thoughts of death or suicide, or suicide attempts.

For purposes of psychological treatment, an individual is considered depressed if he or she exhibits at least four of the above symptoms nearly every day for at least two weeks.

Two major categories of depression are exogenous (i.e., reactive) depression, and endogenous depression. Exogenous depression typically results from loss of-or separation from-an important person or thing. Endogenous depression is usually severe, has no apparent cause, and may be accompanied by delusions.

Major depressive disorder interferes with day-to-day function at work, in social settings, and in other aspects of life. This severe type of depression is characterized by profound and prolonged feelings of emptiness, sadness, loss of interest or pleasure in nearly all activities, and possibly suicidal impulses. People with this disorder are likely to feel worse in the morning than they do at night

Dysthmia is a mild, extremely common form of depression. These individuals can function, but get little joy from everyday activities.

Seasonal affective disorder (SAD) typically occurs during the winter, and usually in northern climates. Symptoms include low mood, poor motivation, lack of energy, and weight gain.

Manic-depression is also known as bipolar disorder. Symptoms usually emerge in the late teens and early adult life. The manic phase is characterized by hyperactivity, increased irritability, and reduced need for sleep. Symptoms of the depressive phase are the same as symptoms of a major depressive disorder.

Postpartum depression is a set of conditions that affects 10 to 20 percent of women who have given birth, and it can last for months. Depending on the woman, it can manifest as depression, anxiety, obsessive-compulsiveness, or all three.

Mind and body are a single package, and what affects one area invariably affects the other. The nervous, immune, and endocrine systems of the body are in constant communication, explains physician and author Andrew Weil, M.D. Several studies have demonstrated that depression weakens immune function.

In one study, Bernard S. Linn, M.D., professor of surgery at the University of Miami School of Medicine, and Margaret Linn, Ph.D., professor of psychiatry at the University of Miami, investigated a group of 29 men. These men had all experienced a recent death or serious illness within their families. The researchers found that the men's white blood cells-which help protect the body from diseases such as cancer-were not functioning properly. Chronic depression is also believed to increase susceptibility to conditions such as rheumatoid arthritis, allergies, and even AIDS. Furthermore, depression has been associated with diabetic complications, chronic fatigue syndrome, and asthma attacks. It may also generate self-destructive behaviors, such as alcohol abuse and other dangerous addictions.

Although serious depression calls for professional medical intervention, improving one's diet is a step in the right direction. A balanced diet and nutritional supplementation can help minimize emotional instability. A good "mental-health" diet includes plenty of fresh vegetables, fruits, whole grains, seeds, pure water, and small amounts of low-fat fish, poultry, and dairy products. A diet rich in fiber and complex carbohydrates, and low in saturated fats and sweets, can effectively nourish body and mind.