What is clinical depression?

What doctors call major depressive disorder, a type of clinical depression, is signaled by changes in feelings and behaviors. If you're clinically depressed, you may feel sad or empty. Things that interested you or made you happy may not interest you now. For example, you may not enjoy your favorite hobbies or being with friends. You may have changes in your appetite or weight or be unable to sleep or sleep too much. You may feel slow, with little energy. You may feel worthless or guilty or have a hard time thinking or paying attention. You may think that life is not worth living, and you may even think about death or suicide. You may feel nervous and anxious. You may have pains such as backache, headache, or stomachache with no other medical cause.

What Are the Symptoms of Major Depressive Disorder?

People who have major depressive disorder have at least 1 of these 2 symptoms nearly every day for at least 2 weeks.


  • depressed mood that seems to continue nonstop, including feelings of sadness or emptiness
  • loss of interest or pleasure in activities that were once enjoyed, such as hobbies, movies, or sex

They also have at least 3 symptoms from this list.

  • feeling hopeless, helpless, guilty, worthless, or pessimistic
  • problems sleeping, including getting to sleep or staying asleep, or oversleeping
  • poor appetite or significant weight loss, or overeating, cravings for certain foods, and significant weight gain
  • fatigue, little energy, or feeling as if they are moving in slow motion
  • feeling restless and irritable
  • problems paying attention, remembering, thinking, or making decisions
  • feeling as if life is not worth living; thinking about or making suicide attempts
  • physical problems, such as headaches, stomach problems, or pain, that don't appear to have another cause and don't respond to treatment