Losing interest, sleeping often, isolating yourself, frequent crying, and severe sadness are all symptoms of depression, among others. Whether you have lost interest in things you used to enjoy, want to sleep all the time or at least stay wrapped up in bed, or see yourself isolating from your essential relationships and withdrawing from life, depression is a miserable experience that can leave you lifeless and even wanting to die. The good news is that most people with depression, even severe depression, can get better with treatment.