The Patient Health Questionnaire-9 (PHQ-9) is a quick, 10-question test that attempts to objectify an inherently subjective topic: depression. You can take the test here.
Each question asks about your mental health and various behaviors over the past two weeks. Based on your response, you receive a score of 0-3 for each question. At the end of the test, the responses are tallied and a "depression score" is assigned as follows:
0-4: None or minimal
15-19: Moderately severe
The test is far from comprehensive. It does not, for instance, ask about...