Although the two conditions share many of the same symptoms, such as feelings of hopelessness, restlessness, and persistent anxiety, fundamental differences between anxiety and depression do exist. In people who are depressed, thoughts generally dwell on the past; while those suffering from anxiety tend to worry about how to control future events. Anxiety is a more active mental process, like anticipation about what may happen. Depression is a passive mental process, an acceptance that things are hopeless. There are differences in physical symptoms too. People who are anxious are usually physically aroused and agitated. Depression is more about slowing down. People who are depressed have no energy or drive.
Read the entire article here: Depression or Anxiety: How to Tell the Difference