Lynch et al. (Reference Lynch, Laws and McKenna2010) provide a fascinating meta-analysis showing that when cognitive behavioural therapy (CBT) is compared with a psychotherapy or pill placebo control group, CBT is no more effective in reducing symptoms of schizophrenia or bipolar disorder than other approaches, and is only slightly better at improving depression. This finding stands in stark contrast to the large literature that shows that CBT is effective when compared with waiting-list controls (e.g. Roth & Fonagy, Reference Roth and Fonagy2005). Rather, the finding is consistent with a now overwhelming body of evidence suggesting that all the main established psychotherapies are equivalently effective (e.g. Luborsky et al. Reference Luborsky, Singer and Luborsky1975; Wampold et al. Reference Wampold, Mondin, Moody, Stich, Benson and Ahn1997; Ward et al. Reference Ward, King, Lloyd, Bower, Sibbald, Farrelly, Gabbay, Tarrier and Addington-Hall2000). Whilst CBT works, it does not appear to work better than other approaches. We suggest that the research focus should now move from establishing the effectiveness of any one technique, towards studying what common mechanisms underlie all therapeutic contact. Similarly, we suggest that practitioners should now decide what therapy to practise on grounds other than simple efficacy.

Component isolation studies do not support the argument that CBT operates through the theoretically expected mechanisms. These studies involve two therapy groups that are identical in all ways, except that one group has had the theoretically ‘active’ component removed. A recent meta-analysis (Ahn & Wampold, Reference Ahn and Wampold2001) showed that removing the theoretically ‘active’ component had no effect on the effectiveness of the therapies. Further, the data trended towards suggesting that the group without the theoretically active component was actually more effective (an effect in the opposite direction).

Component isolation studies coupled with evidence of equivalence between psychotherapies suggest that all therapies operate through the same common mechanisms. Counselling psychology has long suggested this is the case, proposing mechanisms such as the quality of the therapeutic relationship (Rogers, Reference Rogers1957), whilst others have focused on the process of engaging in psychotherapy (Wampold, Reference Wampold2007), or the cognitive changes associated with all therapeutic change (Higginson et al. Reference Higginson, Mansell and Woodin press). Lynch, et al.'s (Reference Lynch, Laws and McKenna2010) study suggests that future research would be better advised to focus on empirically establishing the mechanisms by which all therapies work.

Unfortunately, with increasing evidence that CBT is not more effective than other therapies, the CBT movement appears to be in some crisis, and to be responding not with an increased focus on mechanisms, but rather by spawning endless ‘third-wave’ CBT approaches. These have not been shown to be superior to what is currently available, largely as they are not being compared with other existing therapies. Indeed, some third-wave approaches (see Mansell, Reference Mansell, House and Loewenthal2008) appear to bear little resemblance to CBT as originally conceived. Perhaps in diversifying the practice of CBT in the search of superior efficacy, we are witnessing the dissolution of the ‘brand image’, and the shift to an approach that cannot be distinguished from counselling psychology. We certainly hope that attitudes within the CBT community will become so inclusive, but in this case there needs to be a greater focus on common mechanisms, and less on increasingly arbitrary divides between the ‘in-group’ (CBT) and the ‘out-group’ (counselling psychologists).

With the argument for the overwhelming superiority of the effectiveness of CBT being empirically disproven, practitioners are now left with the question of which therapy to choose, to which there are at least four possible answers. First, a defeatist approach would be that the decision is irrelevant, as all therapy is equal. Second, a more pragmatic approach would be to focus therapeutic activity around the currently best-supported mechanisms. This would be aided greatly by more empirical work into what these mechanisms are. Third, therapists could focus on outcomes other than simple effectiveness. An attractive approach would be to choose the cheapest therapy (Bower et al. Reference Bower, Byford, Sibbald, Ward, King, Lloyd and Gabbay2000). Alternatively, other outcomes could be studied such as authenticity (Wood et al. Reference Wood, Linley, Maltby, Baliousis and Joseph2008); there is suggestion that whilst therapies are equivalent on the outcome of the presenting problem, CBT may outpace humanistic therapy on cognitive exploration, but underperform on affective exploration and insight (Shechtman & Pastor, Reference Shechtman and Pastor2005) – thus superiority, equivalence, or inferiority may be outcome specific (Joseph & Wood, Reference Joseph and Woodin press).

Fourth, the decision could be based on moral grounds. All therapeutic contact is based on the therapist's assumptions and beliefs (Wood & Joseph, Reference Wood and Joseph2007). For example, there is a basic philosophical distinction to be made between directive and non-directive therapies. An unintended consequence of directive psychotherapies may be to disempower the client, and direct them to a life course that is wrong for them (Joseph & Linley, Reference Joseph and Linley2006).

Debates over the role of therapy are not new, but recent years have seen the debate become overshadowed by arguments for effectiveness when in fact this is in part a political and moral decision (Proctor, Reference Proctor, Joseph and Worsley2005). We welcome Lynch et al.'s (Reference Lynch, Laws and McKenna2010) landmark study as it provides a compelling argument that the psychological science of therapeutic practice needs to chart a new course, one that can now focus on finding common mechanisms, and seriously debate the considerations underpinning the choice of therapy. Such work is especially urgent if new attempts to improve access to psychotherapy services (Layard, Reference Layard2006; Boyce & Wood, Reference Boyce and Wood2009) end up supporting one therapy over another, on the false assumption that it is superior, to the disenfranchisement of other effective therapies.