Psychological treatments for eating disorders (EDs) and obsessive-compulsive disorder (OCD) have been shown to be effective in many studies. The specific mechanisms of change in treatments for EDs are not entirely clear, but it is suggested that psychoeducation, collaboration, exposure-based interventions, cognitive therapy, interpersonal effectiveness, and value-based interventions may be active treatment ingredients. Psychoeducation and collaboration between patient and therapist are essential to provide information about the disorder and its causes, challenge negative appraisals and self-criticism, and foster a collaborative environment. Exposure and behavioral experiments are often used in the treatment of both disorders. The goals of exposure include reducing anxiety by repeated contact with a feared stimulus and eliminating avoidance, safety, or escape behaviors, as well as increasing distress tolerance and extinction learning. Cognitive therapy, interpersonal effectiveness, and value-based interventions in ED treatment aim to increase self-efficacy and self-esteem through decreasing interpersonal problems and shifting values that are based on appearance.

Exposure therapy is widely recognized as an effective psychological treatment for OCD but it is not successful in every case. Poorly executed exposure techniques could be implicated. Negative perceptions contribute to poor execution, pitfalls, or the underutilization of this therapy altogether. This, along with common ED misconceptions that are cultural and disorder-specific, can also result in poor treatment for those with EDs. It is important that the therapist has a thorough understanding of the patient’s presentation to ensure that exposures target the precise core fear for new learning. Lack of understanding can lead to mistakes and missed opportunities to enhance exposure, such as failing to explain the rationale, reducing safety behaviors, or overusing a hierarchy. An inexperienced therapist may not understand the importance of discussing the role of family and friends and how their accommodation can perpetuate symptoms, hindering new learning and preventing lasting change. The therapist should be able to identify the core fear, triggers, and avoidance behaviors in the patient and use strategies to enhance inhibitory learning and maximize the chances of successful treatment.

Cognitive behavioral therapy (CBT) and exposure and response prevention (E/RP) remain the treatments of choice for OCD, but for many clients outcomes are suboptimal. In the first part of this chapter, we present the CBT approach to OCD, alongside four promising areas to inform and refine current interventions, namely, optimizing E/RP with inhibitory learning principles; understanding complexity in OCD, differences in disgust, and harm avoidance; and using imagery rescripting for clients with intrusive images. In the second part, we provide an updated CBT and E/RP approach to OCD that integrates these areas into the standard assessment and treatment protocol. The approach emphasizes the importance of a clear developmental formulation with links of past relevant experiences to current OCD, and understanding the context, function, and unintended consequences of obsessions and compulsions. OCD measures and screening tools are introduced.

Cognitive behavior therapy (CBT) is the treatment of choice for people with body dysmorphic disorder (BDD). The first part of the chapter describes the clinical features and processes of BDD, and introduces an updated CBT model of the self as an aesthetic object that evolves around the notion that people with BDD experience distressing mental imagery of their disliked features, maintained by self-focused attention and safety-seeking behaviors. In the second part of the chapter, we present an updated assessment and treatment protocol to BDD. We use case material to illustrate how to engage clients and socialize them into a psychological way of working to overcome their appearance concerns. We illustrate assessment and formulation, how to set up effective behavioral experiments, how to conduct mirror retraining, imagery rescripting, and compassion-focused techniques. BDD screening and diagnostic measures are also presented.

This chapter describes the primary interventions for the fear of aversive consequences presentation of ARFID, including:

• Examples of how avoidance of feared food or eating situations keeps the problem going

• Examples of how facing fears through exposure can actually reduce anxiety

• Creating a hierarchy of feared food and eating situations

• How to design and implement at-home exposures to these feared food and eating situations