Depression is more than just feeling unhappy or fed up for few days; depression is when you feel constantly sad for weeks or months and find it hard to enjoy anything or feel positive about the future.1
Depression can range from mild to severe and is a serious mental health condition that affects people differently.
When depressed, some people might experience psychological difficulties including a persistently low mood, feeling unhappy, tearful or that everything in their lives feels hopeless. Other symptoms can include low self-esteem, feeling anxious and worried, or getting no pleasure from life.
However, symptoms of depression can also be physical, including disturbed sleep, lack of energy or motivation, loss of libido or unexplained aches and pains.1 People with severe depression might also experience suicidal thoughts and desires, self-harm or find it impossible to function.
Reference:
1 NHS overview on Clinical depression, https://www.nhs.uk/mental-health/conditions/clinical-depression/overview/ (accessed January 10th, 2022)