The Patient Health Questionnaire (PHQ-9) (1) is a nine item questionnaire used to assess symptoms associated with depression. Use of the tool will help you better understand the frequency, intensity and impact to functioning of any symptoms your client may be experiencing. By using the questionnaire and noting the results over time, you will be able to understand the patient's overall level of depressive symptoms, changes to their symptoms and the impact of those symptoms on their functioning, and whether self-reported symptoms may reach a significant impact. When considering a diagnosis, you will still need to use clinical interviewing skills to determine whether the symptoms are causing clinically significant distress or impairment, and whether those symptoms are not better explained or attributed to other conditions the client is experiencing.
0-3 item rating assessing presence of symptoms over the past 2 weeks
Total score- 0-27 point scale
Determining clinically significant change is done by exhibiting a person moved from a depressed range (scores greater than or equal to 10) pre-treatment to a non-depressed range (scores less than or equal to 9) post-treatment. Improvement in scores should be 50% or greater of the patients’ pretreatment score; a 5 point or more change in scores indicates reliable change.
As a mental health professional, client care decisions are up to your discretion. However, we recommend attention to the following scenarios related to PHQ-9:
A positive score for question 9: “Thoughts that you are better off dead or of hurting yourself in some way”:
A total score of 20+ which indicates severe symptoms.
An increased change in score by 10+ points