The term “depressed” is used loosely to refer to feeling down or sad. However, the depressive disorder known as “depression” is a much more serious condition that lasts for extended periods of time, not just a day or two every now and then. It results in feelings of sadness and anxiety and can cause a loss of appetite and a loss of interest in doing things the sufferer once enjoyed. Inability to sleep, as well as excessive sleep, is a symptom, in addition to lack of concentration.

The cause of depression is not known, but its presence is associated with substances called neurotransmitters. Neurotransmitters are chemical messengers in the brain, and those most often linked to depression include serotonin, dopamine, norepinephrine and y-aminobutyric acid.

A deficiency or imbalance in these chemicals may lead to depression. Some nutrients from the foods you eat promote production and action of these neurotransmitters; therefore, nutrient deficiencies can affect proper function and risk for depression.