Not everyone who is depressed experiences every symptom. Some people experience a few symptoms, some many. Also, severity of symptoms varies with individuals. 

• Changes in appetite or weight. Many people with depression find that their appetite either decreases or increases. Their weight may shift dramatically, either up or down.
• Sleep disturbances. People with depression may have difficulty falling asleep and may wake up periodically throughout the night. They may wake too early or oversleep. Or they may have trouble staying awake during the day.
• Sluggishness. Depression slows people down -- emotionally, mentally, and physically. People with depression often talk, react, and walk slower than they did before becoming sick.
• Agitation. Depressed people may show signs of agitation, such as fidgeting, pacing, and wringing hands.
• Sexual problems. Depression can drastically hurt a person's sex life. It lowers both desire and enjoyment of sexual activity.
• Digestive disturbances. Nausea, heartburn, indigestion, and abdominal pain are common in depressed people. Other gastrointestinal complaints include constipation and diarrhea.
• Other physical complaints.  Depression can also cause headaches, back and neck aches, muscle cramps, blurred vision and chronic pain. 

• Avoidance and withdrawal. People with depression may avoid everyday or enjoyable activities and responsibilities. They may withdraw from their roles as spouse, parent, friend, student, or employee. The bedroom  or even the internet can become a favorite place to escape and find solitude.
• Clinging and demanding.  The depressed person may become more dependent on some relationships and behave with an exaggerated sense of insecurity.
• Activities in excess. A depressed person may appear to be out of control. He or she may drink too much, abuse drugs, or overeat.
• Restlessness. The restlessness brought on by depression may lead to such behaviors as fidgeting, chain smoking, and going on spending sprees.
• Painful or suicidal gestures. Depressed individuals cause themselves physical pain or take extraordinary risks, such as standing or driving in dangerous places. Tragically, many attempt to end their own lives.

• Negative thoughts.  A depressive mood can bring on an onslaught of negative thoughts, most of which will disappear or diminish once the depression has lifted.
• Difficulty organizing thoughts. People with depression often have problems concentrating or remembering. They may find themselves unable to follow a conversation, an article, or even a TV show plot. Decisions become increasingly difficult.
• Negative view. People with depression may become pessimistic, perceiving themselves, their life, and their world in a very negative light.
• Worthlessness and guilt. Depressed people may obsess over their perceived faults and "failures," feel tremendous
• Helplessness and hopelessness. Depressed people often believe that there is nothing they can do to relieve their feelings of depression and that the illness will never lift.
• Delusions and hallucinations. A person with depression may sometimes see or hear things that do not exist, or believe that an imagined event occurred.
• Death. Depressed people may have frequent thoughts of death and suicide.

• Sadness. Depression brings on feelings of deep sadness. The person may feel despondent and hopeless, perhaps with a sense of doom.
• Loss of pleasure or interest. People with depression lose interest in activities that once brought them pleasure. Experiencing pleasure is increasingly difficult.
• Boredom. People with depression often feel bored  regardless of their environment.
• Anxiety. The person may become anxious, tense, and panicky.
• Turmoil. The person may feel worried and irritable. remorse, and declare themselves worthless. Many blame themselves for feeling and behaving as they do.

 * Ambiguity of diagnosis. The diagnosis  may be a  lengthy process which can be uncertain and ambiguous. (For some people, however, a definitive diagnosis -- coming months or years after the onset of symptoms -- is a relief.   For others, however, it comes as a terrible shock. Both reactions are quite normal.)  

*The unpredictability factor.  Concerns about the unknowns of depression: its course and outcome, concerns about work, family impact and frustrations, about physical limitations and accompanying problems. (It is not uncommon for these concerns to be expressed as anger.) 

*The hidden symptom factor.   Family and friends expect more than the patient feels capable of.  For example, the common symptom of fatigue is frequently misunderstood as laziness or lack of initiative.  This may cause people with depression to doubt their own self-worth.