Depression (mental illness)
The ICD-10 is used around the world to diagnose people with illnesses like depression. According to the ICD-10, for a person to be diagnosed with depression, their symptoms have to last for at least two weeks. The symptoms must happen every day, or almost every day. These symptoms also have to cause problems in a person's life (like their work life, family life, social life, or other important parts of their life).