Depression Caused by Food

The National Alliance of Mental Illness (NAMI) defines depression, which affects 15 million U.S. adults, as a serious medical illness. Its symptoms include extreme sadness, irritability, anxiety, changes in sleeping patterns and energy, and feelings of guilt and low self-worth. Depression, NAMI reports, is the leading cause of disability in the United States. Depression is caused by chemical imbalances in the brain, and the foods you eat can often cause these imbalances.

Chemical Effects

• Decreased serotonin levels in the brain, according to a study by Dr. Richard Wurtman and J.J. Wurtman of the department of brain and cognitive sciences at MIT, can cause food cravings to change, often putting us off carbohydrates. Serotonin is a neurotransmitter that is involved in mood regulation, specifically anxiety reduction, reports Randy Blaun and Andreas Wiesenack in the May 1, 1996, edition of Psychology Today.
  The Wurtmans hypothesized that a lack of carbohydrates can increase the likelihood of depression. Carbohydrates increase the production of serotonin. David Benton and Rachael Donohue of the department of psychology at the University of Wales, Swansea, explain in their study "The Effects of Nutrients on Mood" that tryptophan, the precursor of serotonin, is an amino acid. The Wurtmans report that "Carbohydrates stimulate the secretion of insulin ... insulin secretion speeds tryptophan's entry into the central nervous system ... There it is converted into serotonin."
  High protein diets produce more amino acids that have to get to the brain. According to the Wurtmans, more amino acids mean more contention for tryptophan to hitch a ride into the brain. If it doesn't get there, serotonin levels plummet and a bad mood ensues.

Psychological Effects

• It's really the components of the food we eat that affect us. The Wurtmans found that "Those who were carbohydrate-cravers felt less depressed and more alert. Those who did not crave carbohydrates felt sleepy and fatigued."
  Benton and Donohue found that a lack of vitamins resulted in grouchiness and poorer cognitive skills as well. Benton reports that a diet with thiamine resulted in better moods compared to a diet without thiamine. Foods with thiamine include legumes, cereal, pork, peas and nuts.
  Benton and Donohue also state that "Iron deficiency is associated with reports of poor mood, lethargy and problems of sustaining attention."

Diets

• Skipping breakfast is a poor start to the day. Dr. Susan Biali writes in the July 29, 2009, issue of Psychology Today, "Eating a balanced breakfast and making a point to eat regularly will keep your blood sugar and mood stable."
  Biali also says eating just enough protein makes food stick. "Eating protein with every meal helps the food last longer in your stomach and bloodstream, prevents blood sugar crashes, and also keeps you 'up' and alert for two to three hours afterward." But, she says, keep in mind that too much protein makes a person crabby.
  A lack of B vitamins can also trigger depressive moods. "Research has found that many people who are depressed have low folic acid levels," Biali reports.
  Your bad mood might be because you haven't eaten enough of a certain food, or eaten enough in general. There has to be a balance of nutrients to produce a good mood.