It is often the case that people believe they are suffering from depression when in reality they simply feel sad. Sadness is caused by an event that occurs in the moment, unlike MDD (major depressive disorder), when the individual suffers from a constant feeling of mixed emotions over a long period of time. MDD is a mood disorder that causes one to constantly feel sad and alone. It also leads to a loss of interest in past hobbies and activities and affects the way one feels, thinks and behaves. There are many symptoms and signs of MDD and they always have a cause, but there are always diagnoses and prevention measures for this terrible mood disorder. It is important to understand the symptoms and signs of someone who may be suffering from MDD. This will make it easy to distinguish who may need help, or more importantly, professional help. The most obvious sign for someone with MDD is a constant feeling of sadness and emptiness. It may also include feelings of guilt and preoccupation with failures or past events. A person with MDD may also have trouble sleeping and always feel tired, regardless of how much sleep they got the night before. It is also possible that the individual is constantly oversleeping. There will most likely always be a loss of interest in past hobbies or daily activities like school. Suija, Kalda and Maaroos explained, after their 2009 study of how patients with depression rated themselves, that twenty-four percent of depressed patients said that their social activities were a factor in their problems. health. Only fourteen percent of non-depressed patients agreed. http://proxy4.vaniercollege.qc.ca:2234/ehost/pdfviewer/pdfviewer?sid=e461a...... middle of article... ...s Collection. Internet. May 1, 2014. Beck, Aaron T., MD, and Brad A. Alford. Depression: causes and treatment. Np: University of Pennsylvania, 2009. Print. Canadian Government. Health and social services Quebec. Government of Quebec, 2014. Web. May 1, 2014. Mayo Foundation for Medical Education and Research. Depression (major depressive disorder). HONcode, 2014. The web. May 1, 2014. .Suija, Kadri, Ruth Kalda and Heidi-Ingrid Maaroos. “Patients suffering from depressive disorder, their comorbidity, their visit rate and their disability in relation to self-assessed physical and mental health: a cross-sectional study in family medicine.” BMC Family Practice 10. (2009): 1-8. Academic research completed. Internet. May 1 2014.