The commonest is depression.This may lead to further complications , which are as under (Mayo Hospital): * Loss of interest in normal daily activities. You lose interest in or pleasure from activities that you used to enjoy. * Depressed mood. You feel sad, helpless or hopeless, and may have crying spells. In addition, for a doctor or other health professional to diagnose depression, most of the following signs and symptoms also must be present for at least two weeks. * Sleep disturbances. Sleeping too much or having problems sleeping can be a sign you re depressed. Waking in the middle of the night or early in the morning and not being able to get back to sleep are typical. * Impaired thinking or concentration. You may have trouble concentrating or making decisions and have problems with memory. * Changes in weight. An increased or reduced appetite and unexplained weight gain or loss may indicate depression. * Agitation. You may seem restless, agitated, irritable and easily annoyed. * Fatigue or slowing of body movements. You feel weariness and lack of energy nearly every day. You may feel as tired in the morning as you did when you went to bed the night before. You may feel like you re doing everything in slow motion, or you may speak in a slow, monotonous tone. * Low self-esteem. You feel worthless and have excessive guilt. * Less interest in sex. If you were sexually active before developing depression, you may notice a dramatic decrease in your level of interest in having sexual relations. * Thoughts of death. You have a persistent negative view of yourself, your situation and the future. You may have thoughts of death, dying or suicide. Depression can also cause a wide variety of physical complaints, such as gastrointestinal problems (indigestion, constipation or diarrhea), headache and backache. Many people with depression also have symptoms of anxiety. It is difficult to tell how much time it is going to take as children respond very quickly and older patients a bit difficult to tackle with, no specific time can be given with confidence. THIS IS ALSO KNOWN AS BUMP ON THE HEAD.