Letters. Duckworth and Gilbody debate whether Google should offer an online screening test for depression—namely, the patient health questionnaire 9 (PHQ-9). As the website Patient points out, PHQ-9 “is not a screening tool for depression, but it is used to monitor the severity of depression and response to treatment. However, it can be used to make a tentative diagnosis of depression in at risk populations, such as those with coronary heart disease or after stroke.” Using PHQ-9 as an online screening tool is highly inappropriate. To read the full article, log in using your NHS OpenAthens details.