· Lack of interest in or pleasure from activities typically enjoyed
· Difficulty thinking or concentrating
· Feelings of worthlessness, hopelessness, helplessness or guilt
· Changes in sleep habits and energy levels
· Significant weight gain or weight loss
While the exact cause of depression is not known, the leading scientific theory is that depression is caused by an imbalance of the brain’s neurotransmitters. Neurotransmitters are chemical messengers that send signals between brain cells. Depression is most often treated with antidepressant medications. It is believed that antidepressant medications work by increasing the levels of these neurotransmitters.