About 10% of men and 20% of women will experience a major depression at some point in their lifetime. It is still not known why women tend to be more vulnerable. Major depression can occur in the aftermath of very upsetting life events and circumstances, or it may occur for no apparent reason, when everything else seems to be going well. Either way, major depression is believed to involve chemical messengers or neurotransmitters in the brain. Signs and symptoms of major depression include:

• Depressed mood
• Decreased interest or pleasure in activities
• Significant weight loss or gain
• Not sleeping or sleeping too much
• Being restless or being slowed down
• Fatigue or loss of energy
• Feelings of worthlessness or guilt
• Decreased concentration or ability to make decisions
• Thoughts of death

Major depression is more than “the blues” and includes a range of symptoms. The disorder is very responsive to treatment. Left untreated, it can become increasingly harder to treat and can progress to psychosis and/or suicide. Major depression can be a recurrent illness; it can return quickly, or even years after successful resolution. Major depression can be treated with either psychotherapy or antidepressants, although both are frequently used together.