The role of expectations in mental disorders and their treatment

Expectations are defined as cognitions which are future-directed and focused on the incidence or non-incidence of a specific event or experience1. In the treatment of mental disorders, examining and modifying patients’ expectations is discussed as a central mechanism of change2, 3. This focus on expectations does not disregard any past experiences, but considers them only of relevance if they determine predictions about future events. The relevance of expectations for clinical conditions and their treatment can be illustrated by the following example: temporary ear noises are no problem for most people, as long as the affected persons expect them to vanish promptly. However, the same experience is difficult to bear if affected people expect them to last forever. Analogously, it may be not the negative mood, the unpleasant stimulation, the adverse life event per se that determines whether exposed people develop a mental or psychosomatic disorder, but the expectation about the timeline of the aversive condition, expected future threats, expected curability, and expected competence to cope with the unpleasant experiences. Neurobiology and psychological sub-disciplines such as developmental psychology and social psychology have focused on expectations for decades. They provide us with detailed knowledge on how expectations are formed, under what circumstances they are modified, or when they persist despite contradictory experiences. Expectations lead to brain activities that sensitize for the expected experience4, and they are closely linked to affective reactions5. “Prediction error” paradigms and their association with dopaminergic activation, amygdala activation during aversive coding, and the role of contextual information in the generation of expectancies are just a few neurophysiological examples of how the topic has been investigated. Associative learning, influences via group norms and media, and the phenomenon of sticking to expectations despite expectation violations (cognitive “immunization”) are psychologically relevant concepts to better understand why specific expectations are present. We currently face the challenge of investigating the role of expectations from a clinical perspective and transferring this knowledge into psychotherapeutic and psychopharmacological practice. This approach may allow for a better understanding of the dynamics of mental and psychosomatic disorders, guiding the development of tailored interventions based on highly effective mechanisms. Moreover, focusing on expectations and their persistence helps to explain why some treatments fail. Some mental disorders are “expectation disorders” by definition. This is particularly so in the case of anxiety disorders, such as phobias, panic disorder and generalized anxiety disorder. In these cases, patients expect adverse consequences when being exposed to specific stimuli, situations, or experiences (e.g., the phobic stimulus, the experience of palpitations). In obsessive-compulsive disorder, the patient expects dreadful consequences if compulsive behaviors are prohibited. The role of expectations in post-traumatic stress disorder (PTSD) seems to be more complex. While most people feel secure and do not expect horrible events, this basic confidence in everyday life situations is violated if people suffer from trauma6. Some patients with PTSD do not want to talk about the trauma because they do not expect to be able to bear the emotions that will arise. In other mental disorders, expectations are not part of the diagnostic criteria, but are also of relevance. For example, individuals suffering from depression show more depression-specific negative expectations7. Even in general medical conditions, expectations and expectation-associated concepts (e.g., fear avoidance in chronic pain) have been shown to predict persistence and survival8. Expectations about treatment success are the most prominent predictor of outcome, both in psychopharmacological and psychological interventions, and they are considered to be a major determinant of placebo effects9. In most psychopharmacological trials, placebo responses represent a substantial proportion of the overall treatment effect. Optimizing treatment expectations can result in improved outcome and prevention of treatment side effects, while the induction of negative expectations can abolish the effects of highly effective medications10. If expectations are one of the most powerful predictors of outcome, interventions must maximally modify illness-specific expectations, and positive outcome expectations should be sufficiently established before treatment starts. One of the traditional psychological interventions that may be considered a powerful tool to change expectations is exposure therapy. However, traditional exposure therapy needs to be reformulated to better focus on the change of expectations (e.g., explicit comparison between pre-exposure expectations and post-exposure experiences)3. Expectation-focused psychological interventions (EFPI)7 place a strong focus on analyzing and summarizing disorder-specific expectations of the patient, developing situational tests to check the credibility of these expectations, and re-evaluating expectations by comparing pre-existing expectations with the experience during exposure. In addition to disorder-specific expectations, the baseline expectations about positive and negative effects of interventions should play an important role in treatment planning. If patients have negative attitudes about drug therapy, these attitudes should be addressed before starting medication. In psychological therapies, positive outcome expectations should be established before more challenging interventions are suggested. Considering the large effects that must be attributed to placebo mechanisms in psychiatry, expectations and their modification can be considered the most powerful mechanism for successful treatment. Therefore, there is an urgent need to utilize knowledge about expectations to improve treatment outcomes. Winfried Rief, Julia Anna Glombiewski Department of Clinical Psychology and Psychotherapy, Philipps-University of Marburg, Marburg, Germany