BMJ Open 2:e000800 doi:10.1136/bmjopen-2011-000800
  • Health informatics
    • Research

Do adverts increase the probability of finding online cognitive behavioural therapy for depression? Cross-sectional study

  1. Christopher J Williams3
  1. 1School of Nursing and Midwifery, Plymouth University, Plymouth, UK
  2. 2School of Computing and Mathematics, Plymouth University, Plymouth, UK
  3. 3Institute of Health and Wellbeing, MVLS University of Glasgow, Glasgow, UK
  1. Correspondence to Professor Ray B Jones; ray.jones{at}
  • Received 21 December 2011
  • Accepted 15 March 2012
  • Published 16 April 2012


Objective To estimate the effect of online adverts on the probability of finding online cognitive behavioural therapy (CBT) for depression.

Design Exploratory online cross-sectional study of search experience of people in the UK with depression in 2011. (1) The authors identified the search terms over 6 months entered by users who subsequently clicked on the advert for online help for depression. (2) A panel of volunteers across the UK recorded websites presented by normal Google search for the term ‘depression’. (iii) The authors examined these websites to estimate probabilities of knowledgeable and naive internet users finding online CBT and the improved probability by addition of a Google advert.

Participants (1) 3868 internet users entering search terms related to depression into Google. (2) Panel, recruited online, of 12 UK participants with an interest in depression.

Main outcome measures Probability of finding online CBT for depression with/without an advert.

Results The 3868 users entered 1748 different search terms but the single keyword ‘depression’ resulted in two-thirds of the presentations of, and over half the ‘clicks’ on, the advert. In total, 14 different websites were presented to our panel in the first page of Google results for ‘depression’. Four of the 14 websites had links enabling access to online CBT in three clicks for knowledgeable users. Extending this approach to the 10 most frequent search terms, the authors estimated probabilities of finding online CBT as 0.29 for knowledgeable users and 0.006 for naive users, making it unlikely CBT would be found. Adding adverts that linked directly to online CBT increased the probabilities to 0.31 (knowledgeable) and 0.02 (naive).

Conclusions In this case, online CBT was not easy to find and online adverts substantially increased the chance for naive users. Others could use this approach to explore additional impact before committing to long-term Google AdWords advertising budgets.

Trial registration This exploratory case study was a substudy within a cluster randomised trial, registered on (reference: NCT01469689). (The trial will be reported subsequently).


  • To cite: Jones RB, Goldsmith L, Hewson P, et al. Do adverts increase the probability of finding online cognitive behavioural therapy for depression? Cross-sectional study. BMJ Open 2012;2:e000800. doi:10.1136/bmjopen-2011-000800

  • Contributors RBJ had the idea for the study, is principal investigator, grant holder, was responsible for day-to-day management of the project, carried out most analyses, wrote and edited the paper. LG contributed to the research proposal, is co-grant holder, undertook day-to-day management, did some of the analyses, helped write and edit the paper. CJW contributed to the research proposal, is co-grant holder and edited the paper. PH advised on the interpretation of the data and edited the paper. MNKB advised on the interpretation of the data, co-wrote and edited the paper.

  • Funding The project was funded by a grant from the BUPA Foundation Philip Poole-Wilson Seedcorn Fund. All authors are independent from the funding body.

  • Competing interests CJW is the designer and author of the LLTTF site.

  • Ethics approval Ethics approval was provided by South West Ethics Committee. Ethics committee approval reference: 11-H0203-8.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No other data are available to share.

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