Symptoms of depression range from the obvious low mood to the seemingly unrelated tell tale sign of memory loss.  The severity and types of symptoms vary with individuals and vary over time.  Since depression manifests itself with such a wide array of experiences, it may difficult to diagnose and often goes untreated.  Recognizing the symptoms, however, is the most important step in successful treatment of depression.  These symptoms include:

• Persistent sad or "empty" mood
• Anxiety
• Irritability
• Unexplained crying
• Fatigue or unexplained loss of energy
• Loss of enthusiasm
• Memory loss
• Unexplained weight loss or weight gain
• Insomnia, early-morning awakening, or oversleeping
• Restlessness
• Difficulty concentrating or making decisions
• Feelings of being in "slow motion"
• Feelings of hopelessness
• Feelings of pessimism
• Feelings of guilt
• Feelings of worthlessness
• Feelings of helplessness
• Loss of interest or pleasure in hobbies and activities once enjoyed
• Decreased interest in sex
• Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders, and chronic pain
• Thoughts of death or suicide or attempted suicide