Online screening test for depression is inappropriate
BMJ 2017; 359 doi: https://doi.org/10.1136/bmj.j4736 (Published 17 October 2017) Cite this as: BMJ 2017;359:j4736
- Avril Danczak, GP
- Central and South Manchester Specialty Training Programme for General Practice, Health Education England North West, Education and Research Centre, Wythenshawe Hospital, Manchester M23 9LT, UK
- avril.danczak{at}btinternet.com
Duckworth and Gilbody debate whether Google should offer an online screening test for depression—namely, the patient health questionnaire 9 (PHQ-9).1
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.”2 Using PHQ-9 as an online screening tool is highly inappropriate.
Such screening can also be totally inaccurate. Positive responses indicating depression can be the result of hypothyroidism (affected patients might have less energy, be gaining weight, and be feeling bad about themselves as a result), anaemia, or other chronic undiagnosed disease. The potential for harm through overdiagnosis or wrong diagnosis is inevitable.
The possibility of inappropriate drug advertising direct to patients via Google is also particularly worrying. As Google uses algorithms related to previous searches, could we see unintended consequences, such as links to suicide websites too?
Screening is seen as a “no brainer” by many, with little appreciation of the limitations and harms possible. Perhaps all adverts for screening should come with disclaimers explaining whether they meet Wilson and Jungner’s criteria for an effective screening programme.3
Footnotes
Competing interests: None declared.