Major Depression also called Clinical depression is a mental health disorder identified by continual depressed mood or loss of interest in activities, causing significant impairment in daily routine or normal daily life.
Possible causes include a blend of biological, psychological and social sources of distress. Research indicates that these factors may cause changes in brain function, including altered activity of certain neural circuits in the brain.
The continual feeling of sadness or loss of interest that characterizes major depression can lead to a range of behavioral and physical symptoms. These may include and not limited to changes in sleep, appetite, energy level, concentration, daily behavior or self-esteem. Depression can also be associated with thoughts of suicide.