Major depression is a prolonged deep sensation of sadness or feeling 'down', blue, hopeless, helpless or worthless. The following are common symptoms associated with depression:

• Feelings of sadness, loneliness, hopelessness
• Loss of interest or pleasure in activities
• Changes in weight or appetite
• Changes in sleep patterns
• Feeling guilty or worthless
• Difficulty concentrating, remembering things or making decisions
• Fatigue or loss of energy
• Restlessness or irritability
• Thoughts of death or suicide
• Headaches, joint pain, back/shoulder pain, stomach pain/indigestion

Depression is NOT something you can just snap out of or get over. The first step is to understand facts about depression, and to understand that you are not alone. About one in six Americans experience an episode of depression at some time during his/her adult life.

Often, but not always, depression runs in families, and the course it takes is quite variable. Some people may only experience one significant depressive episode in their entire life, while others suffer with chronic depression which requires lifetime treatment.

Depression and pain are often closely related. Sometimes, depression can cause unexplained physical symptoms. Up to 50% of people who are depressed also feel general pain and don't know why. Research is looking for ways to address both the physical and emotional impact of depression symptoms.

Antidepressants don't work for everyone. If you've taken anti-depressants and were dissatisfied with the results, you may have treatment resistant depression.

The behavior of depressed children may differ from adults, so it's important to know the symptoms. You may notice: sadness, withdrawing from family and friends, extreme sensitivity to failure, poor concentration, changes in ability to sleep, and increased irritability.

Depression is caused by chemical imbalance in your brain. Your brain is made up of billions of nerve cells called neurons. These neurons send and receive messages to your entire body using chemical messengers called neurotransmitters. The levels of neurotransmitters, such as serotonin and norepinephrine, affect emotions. When they aren't in balance, the neurons cannot communicate effectively with the rest of the body. This imbalance can cause depression.

Take our Depression Self Assessment