Symptoms of depression can vary widely - and they don’t always involve the sadness or weepiness that people commonly associate with it. Many people will experience intellectual or psychological changes that affect their thinking, sleep, or energy level.

In addition, different types of depression may produce additional symptoms:

 
• Major depression  
• Bipolar disorder  
• Dysthymia  
• Seasonal affective disorder (SAD)

Major Depression

Experts generally agree that a person has clinical depression when he or she experiences some or all of these symptoms nearly every day for at least two weeks:

 
• Depressed mood  
• Persistent feelings of hopelessness, guilt or worthlessness  
• Fatigue or lack of energy  
• Slowed behavior (the feeling of “dragging oneself around”)  
• Reduction or loss of pleasure in life  
• Decreased motivation  
• Negative or pessimistic thinking  
• Loss of interest in friends, activities, hobbies or work  
• Change in eating habits; weight gain or loss  
• Sleep problems, including waking up early  
• Frequent crying  
• Difficulty concentrating, remembering, or making decisions  
• Irritability  
• Being anxious or worried a lot  
• Thoughts of death or suicide  
• Suicide attempt

Understandably, depression can affect all aspects of a person’s life (and the lives of family and close friends, too) because it puts a damper on one’s overall ability to function. A clinically depressed person often becomes unable to enjoy anything, even things they once enjoyed (a condition called “anhedonic”).

 
• Some people are truly disabled during a bout of depression.  
• Others can continue to function in the sense of holding down a job and meeting other obligations - but just being alive becomes a chore.  
• Depression is believed to contribute to at least half of all suicides.

In addition to having the general symptoms of depression, a person experiencing an episode of major depression, also known as melancholia, may also have:

 
• Frequent headaches  
• Other aches and pains with no apparent cause  
• Digestive problems  
• Sexual dysfunction

In children and adolescents, signs of depression may be more recognizable and may include:

 
• Falling grades  
• Irritability  
• Conduct problems  
• Social withdrawal  
• Complaints of physical problems such as headaches and stomachaches  
• Low energy  
• Poor concentration  
• Changes in eating or sleeping patterns

In the elderly, depression may be accompanied by a focus on physical ailments, such as stomach upset or aches and pains.