Depression can vary widely in severity, and it's normal to have feelings of sadness from time to time. Most everyone experiences reduced self-esteem, pessimistic thoughts, or brief periods of social withdrawal when they fail to achieve something, or when they lose someone important to them. These feelings are usually temporary, and normally don't effect a person's ability to function. However, people with major depression tend to experience more severe changes in mood, and these changes often affect their daily functioning. There are a variety of symptoms associated with major depression, including poor appetite, weight loss, and reduced physical activity. Depressed individuals may lose interest in activities that would normal give them pleasure, have difficulty concentrating and making decisions, display indifference, and have recurrent thoughts about death or even attempt suicide. People with major depression often have faulty perceptions of reality, and are likely to exaggerate the importance of their negative experiences. In some cases, this can lead to delusions of unworthiness, misplaced feelings of guilt, and frustration with the self. Severely depressed people may even experience hallucinations such as hearing condemning voices. Fortunately, treatment for depression is highly successful, and may involve both psychological counseling and drug therapy. For more information about depression, consult a healthcare provider in your area.