When stress is too great for a person and his or her adjustment mechanism is unresponsive, depression may be triggered. When Your Loved One is Depressed, says that in a marriage, if one partner is chronically depressed, the other probably will be too. Researchers have found that some people are powerful mood transmitters and others are mood receivers. Mood transmitters can control the mood of a family or group of coworkers just by being in the room. Mood receivers are very susceptible to the changing moods of those around them.
Foods greatly influence the brain's behavior.
We believe that a poor diet, especially constant snacking on junk foods, is a common cause of depression. The levels of brain chemicals called neurotransmitters, which regulate our behavior, are controlled by what we eat, and neurotransmitters are closely linked to mood and behavior. The neurotransmitters most commonly associated with mood are dopamine, serotonin, and norepinephrine. When the brain produces serotonin, tension is eased. When it produces dopamine or norepinephrine, we tend to think and act more quickly and are generally more alert.