Overview of Chapters in This Book

This volume presents current knowledge across the three aforementioned dimensions of transdiagnostic research: transdiagnostic mechanisms, theory, and treatment. Following this overview chapter, Harvey (Chapter 2) provides an overview of the impetus, benefits, and challenges confronting transdiagnostic research and treatment. In particular, she presents the case for the unique challenges and opportunities for transdiagnostic research in child and adolescent populations. Taking a developmental framework, Harvey suggests that a transdiagnostic approach may be uniquely suited to account for developmental differences in typical and atypical development (which may be easier to achieve by considering dimensional constructs), the presence of multiple reporters, and the high rate of comorbidity. She points to a number of general advantages of taking a transdiagnostic approach, including rapid transfer of treatment breakthroughs, an increased attention to basic science in developing our treatments, and an integration of our disciplines.

Part II highlights research on basic intra- and interpersonal processes that influence the development and maintenance of psycho-emotional- behavioral problems across disorder classes. Authors took care to explain how basic mechanisms account for problem development within a transdiagnostic framework. Authors were asked to (1) define their basic process of interest, (2) describe what makes this process transdiagnostic, (3) review the empirical literature describing the relation of the process to multiple diagnostic classes, problem sets, or clinical profiles in youth, and (4) outline future directions for continued research within a transdiagnostic framework.

Compas, Watson, Reising, and Dunbar (Chapter 3) use a developmental framework to explore how stress, coping, and emotion regulations serve as transdiagnostic risk factors to explain diagnostic co-occurrence. They present research on exposure to stressful events and chronic adversity as transdiagnostic sources of risk and the ways that children and adolescents regulate their emotions and cope with stress as transdiagnostic protective factors. Using terms familiar to the developmental psychopathology literature (e.g., multifinality, equifinality), they encourage a new way of envisioning transdiagnostic work, including an emphasis on developmental trajectories and multiple causality.

Arditte and Joormann (Chapter 4) review the literature on cognitive processes and the critical roles they play in the experience and regulation of emotion. They distinguish between the multiple levels of cognition (attention, memory, interpretation) and illustrate how each level of cognitive process may universally or distinctively contribute to the onset and maintenance of mood and anxiety disorders.

Chu, Skriner, and Staples (Chapter 5) review evidence for the mechanistic role of behavioral avoidance in promoting and maintaining psychological distress across four major youth diagnostic classes (anxiety, depression, conduct, and impulse disorders). Although research on avoidance predominantly centers on anxiety and mood disorders, the authors make the case that avoidance may play a critical role in maintaining disruptive disorders (e.g., ADHD, oppositional defiant disorder [ODD]), too. Their model proposes that avoidance serves different functions depending on when it manifests itself in the sequence of pathological events.

La Greca and Lai (Chapter 6) provide a comprehensive review of peer relations and interpersonal stressors as transdiagnostic processes. Peer rejection and victimization can serve as universal risk factors for multiple forms of future disorders, and peer acceptance and close friendships can serve as protective factors. This developmental perspective on risk and protective factors creates a road map for examining initial development of problem behavior and also provides direct targets for treatment intervention.

Smith and Dishion (Chapter 7) focus their review on how parent- child interactions might interact with youth problem behavior. The authors make a specific case for mindful parenting as an antidote to the coercive cycle that often builds conflict in the home. They review the evidence for mindful parenting factors, such as positive behavior support, healthy limit setting, and family relationship building, as a universal mechanism for supporting healthy family functioning.

Part III offers a reexamination of traditional therapy models and theories within a transdiagnostic framework. In each chapter, the authors describe how a focus on common processes that underlie disparate diagnostic classes can offer unique insight into client problems and contribute to innovative treatment applications. Authors were asked (1) to describe the “traditional” version of the treatment model, (2) to discuss whether the treatment model was initially designed to be transdiagnostic, and if not, (3) to say what aspects of the treatment merit consideration as a transdiagnostic approach, (4) to review effectiveness data for the treatment model across multiple disorders, and (5) to describe the limits and future directions of the treatment model in transdiagnostic use. Four groups of experts across four major treatment modalities weighed in on this topic.

Kendall, O’Neil, Villabp, Martinsen, Stark, and Banneyer (Chapter 8) review the history and evidence for cognitive-behavioral therapy (CBT) as an integrative treatment model that has broad applicability across numerous disorders. Despite the fact that most evaluations of CBT have been applied to specific identified disorders, the authors make the case that CBT is designed to have broad applicability: the basis of the model is a diathesis-stress model, intervention packages for specific disorders share many common interventions, and aspects of the therapeutic structure are transdiagnostic (therapeutic posture, directiveness, goal orientation).

Young, Mufson, and Benas (Chapter 9) build the case that interpersonal therapy for adolescents (IPT-A) has great promise as a transdiagnostic treatment because the treatment focuses on the universal process of interpersonal relationships. Problems arise and are perpetuated by problematic patterns in interpersonal interactions, whereas quality relations can buffer against problems such as depression and anxiety. The authors review the basic relational mechanisms that explain the onset of mood and anxiety disorders, the critical therapeutic techniques that could be effective across disorder sets, and the outcomes that one would expect to see change.

Dialectical behavior therapy (DBT) was a trendsetter in multiproblem treatments. Ritschel, Miller, and Taylor (Chapter 10) describe how DBT was developed as a principles-based treatment to address the severe and complex presenting problems associated with suicidal behavior and borderline personality disorder. Since its initial development, DBT has been adapted and used for other clinical populations, but because DBT simultaneously drew from multiple theories and implemented diverse therapeutic strategies, it set itself up uniquely as a potential transdiagnostic intervention. In particular, DBT addresses several core mechanisms common to many disorders, including emotion dysregulation, distress tolerance, mindful awareness, social effectiveness, and balanced family interactions.

Coyne, Birtwell, McHugh, and Wilson (Chapter 11) make the case that acceptance and commitment therapy (ACT) is also uniquely suited as a transdiagnostic therapy because it is concerned not with the elimination of syndromes but rather with building broad, flexible behavioral repertoires. Rather than focusing on symptom reduction, ACT promotes acceptance of aversive private experiences in the service of commitment to freely chosen values. Their mechanism of choice is the broader “functional context” of language and behaviors in human experience. To the extent that one can change how one relates to his or her own thoughts, feelings, and actions (i.e., change the relational frame), one can learn to tolerate emotional barriers that interfere with quality living. To the extent that this process is universal to any kind of suffering, this treatment model is inherently transdiagnostic.

Part IV spotlights exemplar treatment protocols that have applied transdiagnostic therapy across diverse clinical settings and client populations. Authors describe the theory underlying their respective approaches, highlight the universal processes that are targeted in the treatment protocol, and report empirical evidence supporting the therapy. Authors were asked to (1) describe the targeted clinical population and treatment intervention, (2) illustrate what makes the treatment explicitly transdiagnostic, (3) discuss distinct developmental considerations in the development or delivery of the treatment, and (4) review the available empirical evidence for the treatment. As this area represents a large domain of future growth, these chapters also highlight future directions in treatment development.

Ehrenreich-May, Queen, Bilek, Remmes, and Marciel (Chapter 12) describe the rationale and subsequent development of two unified protocols, for children and for adolescents, respectively. These protocols follow solidly from the theoretical principles first outlined by Barlow and colleagues (2004; Barlow et al., 2010) in their descriptions of a unified approach to “emotional disorders” but also reflect a lengthy process of iterative treatment development to tailor such work for youth. The protocols are described in detail and, although only open trial and case series results have been published to date, randomized controlled trials (RCTs) of the adolescent (UP-A) and child (UP-C: Emotion Detectives) protocols are nearing completion. These RCT data are viewed as a needed next step to supporting the feasibility and comparative utility of transdiagnostic treatments for anxiety and depressive disorders in youth.

Following this, a fascinating chapter by Lochman, Powell, Boxmeyer, Ford, and Minney (Chapter 13) details the evolution of a treatment, Coping Power, that truly targets a singular mechanism, anger and its regulation, and suggests far-reaching implications for its utility as a transdiagnostic approach. Lochman and colleagues make the case that Coping Power is flexible and comprehensive enough in its structure to accommodate a number of co-occurring problems, beyond the disruptive behavior concerns alone that the intervention was originally designed to influence. Lochman and colleagues illustrate this point throughout their discussion of Coping Power’s components, pointedly tying its processes and strategies to their impact on related behavioral and emotional domains.

Much like DBT, multisystemic therapy (MST) is a comprehensive approach somewhat born of the necessity that a highly impaired population, in this case juvenile offenders, requires a variety of flexible and overlapping intervention strategies, guided by an overarching theoretical and systemic view. Helpfully distinguishing the related classes of transdiagnostic, modular, and principle-based interventions for the reader, Schoen- wald (Chapter 14) does a masterful job of describing MST as a “principle- based, measurement-based, and flexible” intervention that guides case conceptualization and treatment selection for a variety of target populations. Schoenwald further illustrates how MST provides guidance when a population is sufficiently novel to warrant the inclusion of additional techniques and gives examples of such extensions.

Suarez, Ellis, and Saxe (Chapter 15) provide an example of a treatment, trauma systems therapy for adolescent substance abuse (TST-SA), that started with an existing treatment complexity-youth trauma and its aftermath—then extended its reach to be inclusive of a commonly comorbid problem area, adolescent substance abuse. Rather than simply adding new treatment components to address a related concern, Suarez and colleagues describe how their approach views both youth trauma and substance abuse singularly as “dysregulated emotional and behavioral states that occur in the context of a potentially unstable, and at times threatening, environment” and uses central principles of change to address these challenging problems.

Looking through the lens of eating disorders in youth, Le Grange and Loeb (Chapter 16) then describe how individual eating disorders are fundamentally intertwined with one another, both in terms of current symptom presentations and over the longitudinal course of illness. Although it was originally designed for treatment of anorexia nervosa, Le Grange and Loeb convincingly describe the transdiagnostic applications of family-based treatment (FBT) across eating disorder categories in youth. They support this position through both empirical findings across relevant diagnoses and succinct description of how FBT strategies apply both broadly across dysregulated eating patterns and more specifically within the context of varying clinical presentations.

Chapter 17, by Payne, Tsao, and Zeltzer, discusses a focal application of the unified protocol to a new systemic and intrapersonal context: that of a pediatric population with pain. Payne and colleagues note the high incidence of emotional disorders in pediatric samples, along with the potential common mechanisms of change across emotional disorders and pain management. The authors describe the unified model in further detail, along with the substantive adaptations and revisions they have made to better suit the unique challenges faced by children with chronic pain.

In Part V, following the previous sections’ review of contemporary transdiagnostic science and treatment, we were fortunate to have Ollen- dick, Fraire, and Spence, in Chapter 18, provide commentary on the current state of the research. They critically evaluate the current literature base and acknowledge the promise of current efforts but caution the field to wait until further evidence accumulates.

Returning to the simultaneous excitement and confusion that we sought to address, Chu and Ehrenreich-May (Chapter 19) conclude this book with an endeavor to identify the challenges ahead for the trans- diagnotic movement in youth psychopathology. We address the concerns raised by Ollendick and colleagues and look to even further challenges ahead to fully establish the meaning and reach of transdiagnostic research. Although transdiagnostic research and treatment are in their infancy, the current volume demonstrates that they are in a rapid period of development and empirical evaluation. The road ahead is filled with both promise for efficiency in our youth treatments and caution about the need for further research to see this promise fulfilled.