Background: In the UK, bibliotherapy schemes have become a widespread source of support for people with common mental health disorders such as depression. However, the current evidence suggests that bibliotherapy schemes that are offered without guidance are not effective. It may be possible to improve the effectiveness of self-help books by incorporating into them some of the "common factors" that operate in personal therapeutic encounters, for example therapist responsiveness.
Aim: The aim was to test whether and to what extent authors have incorporated common factors into self-help books.
Method: A model of how common factors might be incorporated into CBT-based self-help books was developed and a sample of three books were examined against the model criteria.
Results: The sampled self-help books were found to have common factors to a greater or lesser extent, but some types of common factors were more prevalent than others. Factors addressing the development and maintenance of the therapeutic alliance were less often apparent.
Conclusions: Self-help books have the potential to provide a valuable service to people with depression, but further work is necessary to develop them. It is suggested that future generations of self-help books should pay explicit attention to the use of common factors, in particular developing and investigating how factors such as flexibility, responsiveness and alliance-rupture repair can be woven into the text.