Since the appearance of the two previous editions of Mental Health Outcome Measures (first published by Springer Verlag in 1996, with a second edition published by the Royal College of Psychiatrists in 2001), there have been several intriguing developments in the field. First, an even wider range of important outcome domains are now measurable using well standardised instruments than were measurable before. Second, a greater emphasis upon positive outcomes has evolved (for example referring to the concept of recovery) among researchers, service users and clinicians. Third, the voice of the service user/consumer is now centre stage to a much greater extent than in earlier years. This third edition refers to these three core themes throughout its pages. Nevertheless, the fundamentals remain unchanged, namely:

1. • the scales used must have known and strong psychometric properties (Chapter 2)

2. • evidence (both qualitative and quantitative) needs to be ascertained from the most rigorously scientifically designed studies (Chapter 3), taking into account the complexity of the intervention (Campbell et al, 2000, 2007; Tansella et al, 2006)

3. • in many outcome studies, symptom and social domains (such as quality of life and employment) need to be assessed concurrently (Chapters 5, 8, 9, 11, 13, 14 and 16)

4. • scales need to be applicable and relevant to a wide of settings to allow valid international comparisons (Chapter 17)

5. • an inclusive approach to the whole range of mental disorders is required, so that people are included whose conditions have sometimes been excluded from care, such as personality disorders (Chapter 15).

At the same time, a clear trend is now identifiable not so much to look at mental disorders in terms of their producing chronicity, impairment and severe disability but instead to emphasise the hope of recovery (Chapter 4). Central to this view is the participation of service users in research (Chamberlin, 2005) and a more nuanced approach to potential collaboration between people disclosing experience of mental illness, and others, in the development and use of outcome measures (Sweeney et al, 2009).