I can provide some general possibilities as to why your friends might have used the term "depressed" to describe you:
Observable behavior: Your friends might have noticed changes in your behavior, such as persistent sadness, withdrawal from social activities, or a significant decrease in your usual level of energy and enthusiasm.
Emotional expression: If you have been expressing feelings of sadness, hopelessness, or emptiness to your friends, they might have interpreted it as a sign of depression.
Changes in interests: A loss of interest in activities you once enjoyed or a general lack of motivation might be evident to your friends.
Isolation: If you have been withdrawing from social interactions and spending less time with your friends, they may have noticed this and expressed concern.
Physical symptoms: Sometimes, depression can manifest in physical symptoms like changes in appetite, sleep disturbances, or unexplained aches and pains. If your friends have noticed such symptoms, it could be a reason for their concern.
Academic or work performance: Significant changes in your academic or work performance might have prompted your friends to worry about your well-being.
It's important to note that your friends' observations are not equivalent to a professional diagnosis. If you are concerned about your mental health or have been experiencing symptoms of depression, it's crucial to talk to a mental health professional. They can provide a proper evaluation and offer appropriate support and treatment if needed.
Remember, it's okay to ask for help when you need it, and seeking support from friends, family, or professionals can be an important step in addressing any mental health concerns you may have.