The third wave of cognitive behavioral therapy and the rise of process‐based care

The term cognitive behavioral therapy (CBT) identifies a family of interventions that are widely recognized as the set of psychological treatments with the most extensive empirical support. CBT is not monolithic, however, and it has been through several distinct eras, generations, or waves. The first generation of this tradition was behavior therapy: the application of learning principles to well-evaluated methods designed to change overt behavior. By the late 1970s, behavior therapy had moved into the era of classic CBT: a new generation of methods and concepts focused on the role of maladaptive thinking patterns in emotion and behavior, and the use of methods to detect and change those patterns. The arrival of a “third wave” of CBT was declared 13 years ago. The claim was that a change was occurring in orienting assumptions within CBT, and that a set of new behavioral and cognitive approaches were emerging based on contextual concepts focused more on the persons’ relationship to thought and emotion than on their content. Third wave methods emphasized such issues as mindfulness, emotions, acceptance, the relationship, values, goals, and meta-cognition. New models and intervention approaches included acceptance and commitment therapy, dialectical behavior therapy, mindfulness-based cognitive therapy, functional analytic psychotherapy, metacognitive therapy, and several others. The idea that a “third wave” of CBT had arrived led to significant controversy. The metaphor of a “wave” suggested to some that previous generations of work would be washed away, but that was not the intent and that was not the result. Waves hitting a shore assimilate and include previous waves – but they leave behind a changed shore. It seems to us that we are now in a position to begin to evaluate what will be left behind in a more permanent way from third wave CBT. There is no doubt that several concepts and methods that have been central to third wave interventions (mindfulness methods; acceptance-based procedures; decentering; cognitive defusion; values; psychological flexibility processes) are now permanently part of the CBT tradition and indeed of evidence-based therapy more generally, in large part because evidence suggests that they are helpful. These newer concepts and methods now largely co-exist side by side with previously established ones, with the dialectic between them serving as a useful spur to theoretical and technological investigation. In some cases, we now know that traditional CBT methods work in part by changing processes that became central after the arrival of third wave methods. Third wave methods have been added to packages that include traditional behavioral and cognitive methods, resulting in useful approaches. Research has begun to identify moderators indicating when older and newer methods work best with different populations, suggesting that evidence-based practitioners can serve their clients by knowing methods from all of the CBT generations. While new concepts and methods are important, in our opinion, there is a more profound set of changes that has been introduced by the third wave. A subtle but important change is that there is now greater recognition of the central importance of philosophical assumptions to methods of intervention and their analysis. Science requires pre-analytic assumptions about the nature of data, truth, and the questions of importance, and some of the differences between the waves and generations of CBT work were philosophical, not empirical. Recognizing this, the Inter-Organizational Task Force on Cognitive and Behavioral Psychology Doctoral Education recently concluded that all CBT training should place more emphasis on philosophy of science training, in the hope of increasing the coherence and progressivity of research programs. An examination of assumptions leads naturally to a concern for theories, models, and processes. The third wave has been far less focused on protocols for syndromes, and more focused on evidence-based processes linked to evidence-based procedures. Increased emphasis on processes of change and their biobehavioral impact has meanwhile been strengthened by Research Domain Criteria and transdiagnostic models, among other trends. A notable result is that there is now much more focus on moderators and mediators of change, and the construction of intervention models that emphasize the role of changeable transdiagnostic processes (i.e., functionally important pathways of change that cut across various diagnostic categories). In part because of its greater process focus, modern CBT and evidence-based therapy is more open to the investigation of a wider range of approaches from humanistic, existential, analytic, and spiritual traditions. This promises over time to reduce the dominance within intervention science of walled off schools of thought, or trademarked intervention protocols, and to bring different wings of the field together in an evidencebased search for coherent and powerful sets of change processes. As a purely syndromal focus weakens and a process focus strengthens, human psychological prosperity and the thriving of whole persons, not merely psychopathology, is also becoming more central. Behavioral and mental health is ultimately about health, not solely the absence of disorders. This set of changes is accelerating a transition in evidencebased care toward a process-based field that seeks to integrate the full range of psychosocial and contextual biological processes. Such a field is so broad that it stretches the very term CBT almost to a breaking point and we would not be surprised if that term soon wanes in importance. Researchers and practitioners alike seem ready for a turn toward process-based therapy (PBT), in which processes, procedures and their linkage are evidence-based, and are used to alleviate the problems and promote the prosperity of people. Similar to the trend toward personalized and precision medicine, focusing on changeable processes that can make a difference in