It is much less likely that your initial image of a bird would be something like a penguin or ostrich. A sparrow or robin is closer to the prototype of bird than a penguin or ostrich, although the latter two animals are certainly birds.
Similarly, DSM-5 recognizes that most people with a specific disorder show signs and symptoms similar to the prototype for that disorder; however, DSM-5 also allows for some variability in the way people can manifest these diagnostic features.
You can see elements of the prototypical approach to classification in the DSM-5 criteria for major depression. Although there are three essential features of the disorder, children can manifest the signs and symptoms of the disorder in nine different ways. Only five of these signs or symptoms are required for the diagnosis. For example, some depressed children experience cognitive difficulties, such as problems concentrating on their schoolwork, beliefs that they are worthless, or recurrent thoughts about death. Other children with depression experience physical problems, such as decreased appetite, insomnia, and fatigue. The prototypical approach allows flexibility in the way children experience each disorder.
Dimensional Classification
Dimensional classification assumes that disorders fall along a continuum of severity ranging from mild to severe. It involves describing the severity of the individual’s distress and/or disability on this continuum. One advantage of dimensional classification is that it conveys more information than simple categorical or prototypical classification. For example, rather than merely diagnosing a child with autism, a clinician can describe the child as having mild impairment in social communication but severe behavioral impairment (e.g., repetitive actions and difficulty adjusting to changes in routine). A second advantage of the dimensional approach to classification is that it allows clinicians to monitor changes in children’s functioning across time. For example, a child may continue to meet diagnostic criteria for autism after several years of behavior therapy; however, his repetitive behavior might improve from “severe” to “mild.”
Previous versions of the DSM were criticized for their exclusive reliance on the categorical and prototypical approaches to classification. Consequently, the developers of DSM-5 attempted to incorporate aspects of dimensional classification into the newest edition of the manual. Dimensional classification is most easily seen in the DSM-5 Cross-Cutting Symptom Measure, a rating scale that can be used to evaluate the severity of children’s signs and symptoms. The rating scale allows dimensional classification on 10 broad domains including physical symptoms and sleep problems, anxiety and depression, anger and irritability, and mania and psychotic symptoms. Children’s severity on each domain can be described on a 5-point continuum ranging from “none or not at all” to “severe or nearly every day.”
Table 1.1 shows a clinician’s ratings of an adolescent using the Cross-Cutting Symptom Measure. These ratings show that the adolescent is experiencing moderate to severe problems with depressed mood and irritability but fewer difficulties with anxiety and worry. The ratings provide additional data, above and beyond the adolescent’s diagnosis, and can be used as a baseline from which to assess the youth’s progress in treatment.
Some DSM-5 disorders also allow clinicians to provide additional information about their clients using specifiers. A diagnostic specifier is a label that describes a relatively homogeneous subgroup of individuals with the same disorder. Usually, specifiers are created based on the person’s signs and symptoms. For example, some children with ADHD are primarily hyperactive and impulsive but listen to their parents and teachers, whereas other children with ADHD daydream in class but remain quiet and still. Although all of these children are diagnosed with ADHD, clinicians might assign the specifier “predominantly hyperactive–impulsive presentation” or “predominantly inattentive presentation” to children in the first and second groups, respectively. These specifiers provide a more precise description of children’s behavior than the diagnostic label alone.
Table 1.1
Review
DSM-5 uses a categorical approach to classification because it requires children to meet specific criteria to be diagnosed with a disorder. Youths who do not meet all criteria are not diagnosed with the disorder.
DSM-5 also uses a prototypical approach to classification for many disorders. Children can show a subset of possible signs and symptoms that reflect a typical child with the disorder.
DSM-5 uses a dimensional approach to classification for several disorders. Clinicians can indicate the severity of children’s disability or distress on a continuum ranging from mild to severe.
What Are the Advantages and Disadvantages of Diagnosing Children?
Possible Benefits
Diagnosis has a number of benefits. Perhaps the most obvious benefit to diagnostic classification is parsimony. Imagine that you are a psychologist who has just assessed a 3-year-old child with suspected developmental delays. You discover that the child shows severe and pervasive problems with social communication and repetitive behavior. Instead of describing each of these symptoms, you can simply use the appropriate diagnostic label: autism spectrum disorder.
A second advantage to diagnosis is that it can aid in professional communication. Another mental health professional who sees your diagnosis knows that your client exhibits the signs and symptoms of autism described in DSM-5. The second professional does not need to conduct her own assessment of the child to arrive at an independent diagnosis to know something about the child’s functioning.
A third advantage is that a diagnosis can aid in prediction. If you know that your client has autism, you can use the existing research literature to determine the child’s prognosis or likely outcome. For example, most children with autism show chronic impairment in social and communicative functioning; however, prognosis is best among children with higher cognitive abilities and better developed language skills. The research literature also indicates that children who participate in treatment before age 4 often have the best developmental outcomes. You might share this information with the child’s parents so they can make more informed decisions regarding the child’s education and treatment (Pijl, Buitelaar, de Korte, Rommelse, & Oosterling, 2019).
A fourth and closely related benefit of diagnostic classification is that it can help to plan treatment. If you know that your client has autism, you can also use the existing research literature to plan an intervention. For example, a number of studies have indicated that early, intensive behavioral interventions can be effective in improving the social and communication skills of young children with autism. Other forms of treatment, such as art and music therapy, have far less empirical support (Volkmar, Reichow, Westphal, & Mandell, 2015).
Fifth, diagnostic classification can help individuals obtain social or educational services. For example, the Individuals With Disabilities Education Improvement Act of 2004 (IDEIA) is a federal law that entitles children with autism to special education because of their developmental disability. Special education might involve enrollment in a special needs preschool, early intensive behavioral training paid by the school district, provision of a classroom aide or tutor, academic accommodations, occupational skills training, and other services.
Sixth, diagnostic classification can be helpful to caregivers. Although no parent is happy when his or her child is diagnosed, many parents feel relieved when their child’s
