Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behavior, feelings and sense of well-being.Depressed people can feel sad, anxious, empty, hopeless, worried, helpless, worthless, guilty, irritable, hurt, or restless. They may lose interest in activities that once were pleasurable, experience loss of appetite or overeating, have problems concentrating, remembering details, or making decisions, and may contemplate, attempt, or commit suicide. Insomnia, excessive sleeping, fatigue, loss of energy, or aches, pains, or digestive problems may also be present.

Depressed mood is not always a psychiatric disorder. It may also be a normal reaction to certain life events, a symptom of some medical conditions, or a side effect of some drugs or medical treatments. Depressed mood is also a primary or associated feature of certain psychiatric syndromes such as clinical depression.

What Are the Symptoms of Depression?

For major depression, you may experience five or more of the following symptoms for at least a two-week period:

• Persistent sadness, pessimism

• Feelings of guilt, worthlessness, helplessness, or hopelessness

• Loss of interest or pleasure in usual activities, including sex

• Difficulty concentrating and complaints of poor memory

• Worsening of co-existing chronic disease, such as rheumatoid arthritis or diabetes

• Insomnia or oversleeping

• Weight gain or loss

• Fatigue, lack of energy

• Anxiety, agitation, irritability

• Thoughts of suicide or death

• Slow speech; slow movements

• Headache, stomachache, and digestive problems