Depression and anxiety are amongst the most prevalent psychiatric conditions, affecting up to 8.8% of the population in the UK [1
]. It is estimated that depression in adults could cost the nation over £9 billion a year and could lead to 109.7 million working days lost per year [2
]. To address the problem, there is a strong evidence base for psychological therapy featuring cognitive behaviour therapy (CBT) [3
]. However, conventional CBT is delivered face-to-face, meaning that the resources which would be needed to treat everyone who could potentially benefit for depression are vast.
The past decade has seen growing use of computers and the internet as an adjunct to face-to-face CBT, and in some cases as an alternative to individual contact with a clinician. A computer can be used in different ways; to provide information in written or audio/video formats; as a tool for screening or diagnosis; as a self-help tool, which entails following a structured programme on-line; to simulate situations and permit graded exposure in highly controlled conditions; and as a means of communication between patients and health care professionals for administrative or therapeutic purposes. The attractions of computer-mediated CBT (cCBT) include: its capacity to deliver structured input consistently with precision, low cost, easy accessibility and potential to offer a flexible approach in a non-stigmatising environment. Yet if best use of this resource is to be made, clear knowledge about the effectiveness and costs of alternative cCBT programmes is needed to guide planning and provision of care.
The main focus of this paper is on the delivery of computerised CBT (cCBT) for treating depression with or without anxiety. From a pragmatic perspective, users, clinicians and commissioners of health care are most likely to ask 'what works for people with depression?'. Since we were engaged in a study of MoodGYM, which is a publicly-available cCBT programme developed by the Centre for Mental Health Research at the Australian National University [4
], we wanted to place this study in the context of relevant literature concerning both MoodGYM and other similar programmes which are also primarily designed to treat depression. There have been different reviews on the topic, but their quality and comprehensiveness of their scope has not been studied yet. We therefore set out to review existing reviews, appraise these and draw together what they indicate regarding cCBT for depression, particularly if their results could help us to compare alternative cCBT packages for the same disorder.