For someone who has not been diagnosed, it can be difficult to know where the line is between feeling low and having depression.
The below test - created by Drs Robert L Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues with a grant from Pfizer Inc - aims to help an individual work out whether they could be depressed.
There are many symptoms of depression, including low mood, feelings of hopelessness, low self-esteem, lethargy and sleep problems. The more symptoms someone has, the more likely they are to be depressed.
Take the test to fid out whether or not you're likely to be suffering from depression. Remember, this test is for information only and is not intended to replace a consultation with a GP.