Developmental Psychopathology. Группа авторов

      What is psychopathology? How do we know when a child or adolescent has clinically significant symptoms of a psychological or behavioral disorder? How do we ensure that medical and mental health professionals, patients, and other stakeholders assess for, and communicate about, mental illness in a consistent way? Formal diagnostic systems and other approaches to the classification of psychopathology allow us to answer these questions to varying degrees. In this chapter, we will discuss different approaches to understanding, classifying, and diagnosing psychopathology in children and adolescents. We conclude with a summary of the limitations of each approach and introduce the benefit of a developmental psychopathology approach to conceptualizing psychopathology.

Diagnosis and Classification

Psychopathology is the study of mental disorders. Mental, or psychological, disorders are characterized by behavioral patterns and cognitive, emotional, and physical symptoms that deviate from a normative developmental trajectory and are not typical of individuals living in the same cultural context. “Mental disorders are usually associated with significant distress or disability in social, occupational, or other important activities” (American Psychiatric Association, 2013, p. 20) because symptoms of mental illness can have serious negative impacts on people’s physical health, education, employment, relationships, and well‐being. Unsurprisingly, then, scientists, philosophers, doctors, and other scholars have taken an interest in psychopathology since ancient times. Historically, how have we decided what psychological symptoms or behaviors are considered abnormal? How do we keep track of this knowledge or information to ensure that everyone with an interest in mental health or a role in treating mental health concerns is educated and “on the same page” when it comes to psychopathology? In the modern era, we have facilitated communication about mental health and tried to understand and organize knowledge about psychopathology using classification systems.

      Classification is the act of categorizing things according to a set of criteria. Things in the same category tend to share similar characteristics or features. For example, biologists interested in taxonomy, the science of classification, might classify sea creatures according to dimensions such as size, diet, or gestation process. Classification systems for psychopathology aim to organize the observed symptoms of psychological disorders. The most commonly used and well‐known classification system for mental disorders in the United States (US) is the Diagnostic and Statistical Manual of Mental Disorders (DSM). The most recent version of the DSM, the DSM‐5, contains 22 classes of disorders. Within each class, specific diagnoses are listed and most of these diagnoses list a set of criteria and number of symptoms that must be met for an individual’s functioning to be considered abnormal and for a diagnosis to be given. The diagnoses in each class share similar features. For example, one class of disorders in the DSM‐5 is the anxiety disorders. These disorders “share features of excessive fear and anxiety and related behavioral disturbances” (APA, 2013, p. 189). Diagnoses within the anxiety disorder class differ from one another in the types of situations and objects that cause fear, anxiety, and avoidance behavior, and all the diagnoses within the anxiety disorder class differ from diagnoses in the other classes in important ways. According to the DSM‐5, the organization of symptoms into disorders and disorders into classes based on their shared features is “a historically determined cognitive schema imposed on clinical and scientific information to increase its comprehensibility and utility” (APA, 2013, p. 10). In other words, historical scientific research and clinical wisdom was utilized to organize and classify symptoms in a way that would allow for easier communication between mental health providers, patients, and other stakeholders.

How do classification systems for psychopathology improve our understanding of an individual’s mental illness and communicate about it more easily? Once mental health providers assess for the presence of psychopathological symptoms or observe certain behaviors in their patients, they can use a classification and diagnostic system to organize their findings and come to a differential diagnosis. The process of diagnosing an individual gives mental health providers a starting point, including guidance about the cause of this person’s difficulties, the likely course their symptoms might take, and the outcomes they might experience without intervention. These considerations can have important implications for treatment planning. Classification and diagnostic systems also act as a “shorthand” between providers, with insurance companies, and with government agencies. Rather than describe all the symptoms an individual is experiencing one by one, which could be a time‐consuming process that potentially violates an individual’s right to privacy, mental health providers and other involved agencies can quickly communicate the overall “gist” of a person’s presenting problems by using a classification system to give them a diagnostic label.

      It is important to note that although individuals with the same diagnosis experience some of the same symptoms, they often present with very heterogeneous symptom profiles. Additionally, there is no one etiology underlying the symptoms of these disorders. Therefore, a psychological disorder diagnosis, as described in the DSM‐5, is only a list and description of symptoms that appear to occur together, resulting in a phenotype or set of observable characteristics. This phenotype is often associated with specific outcomes, suggesting that intervention on the phenotype is necessary. But why should we use a classification and diagnostic system, like the DSM‐5, if there are sometimes large differences between individuals with the same diagnosis or uncertainty regarding the cause of diagnoses? In short, it is because diagnoses are useful to us (Frances & Widiger, 2012). They help us do all the things already discussed in this chapter, such as communicate with other professionals and patients, conceptualize patient problems, and identify the most effective interventions possible.

      Psychopathology classification and diagnostic systems are, however, not infallible (Frances & Widiger, 2012) nor definitive. They are simply our best attempt to describe and organize the psychological, behavioral, and emotional phenomena that clinicians and researchers observe in their practices, laboratories, and in the real world. We will now review the history and content of two of the most well‐known and widely used psychological disorder classification and diagnostic systems – the DSM and the International Classification of Diseases (ICD).

The Diagnostic and Statistical Manual of Mental Disorders (DSM)

The DSM is the most well‐known and widely used classification and diagnostic system for psychological disorders in the US. The DSM was born out of the American Psychiatric Association’s (APA) desire to create a coherent system of communication in the field of psychiatry, and the first edition was published in 1952. The DSM‐I contained 128 diagnoses organized into different classes of disorders (Blashfield et al., 2014). The distinct disorders were derived from the clinical experiences of APA members and not through research, as available studies at that time were extremely limited. Each category and diagnosis contained a brief description of that class and the disorders’ symptoms, traits, and behaviors (Blashfield et al., 2014). Of significant note, the DSM‐I contained few references to children or adolescents, or how psychopathology would present itself in these periods of development.

The DSM would go on to be substantively revised five times (DSM‐II, III, III‐R, IV, and 5), with the number of diagnoses listed increasingly steadily since 1952 (see Figure 1.1). Whereas the DSM‐I contained 128 diagnoses, the DSM‐5 contains 541 diagnoses organized into 22 diagnostic categories. Between the publication of DSM‐I in 1952 and the publication of DSM‐II in 1963, studies examining the reliability of psychiatric diagnoses and the clinical utility of categories of diagnoses increased (Blashfield et al., 2014). This provided the APA with some empirical evidence for drafting DSM‐II and began the shift that would lead the DSM from being a descriptive, clinically based classification system to an empirically supported one.

      The publication of DSM‐III was significant because it aimed to bring psychiatry in line with the rest of medicine by ensuring that more information was provided in the text about the symptomology, demographics, etiology, and course of each disorder, basing this information on available empirical evidence.