310 The Nature of Mental Disorders
The terms “mental disorder,” “mental illness,” and “psychopathology” are often used interchangeably by those in psychology and related fields; all refer to the study of unusual or abnormal behaviors. Unlike terms and concepts in many of the physical sciences, however, there is not a single, agreed-upon by all operational definition for these terms. The primary definitional conflict hinges on this question: Can mental disorders be defined as a scientific term, or are they instead socially constructed?
This lack of a single definition can lead to confusion and communication problems both when mental health professionals, such as psychologists, psychiatrists, counselors, or social workers, attempt to talk to each other and to the general public. As a result, mental disorders are used and defined in a variety of ways. Before beginning our examination of anxiety disorders, we must discuss these definitions and decide which one (or ones) will guide this book. Below are descriptions of the most common perspectives.
Mental Disorders as Statistical Deviance
The statistical deviance perspective has enormous common sense appeal, as it involves defining abnormal behavior by comparing an individual’s behavior to the frequency of occurrence of the same behavior in the general population. A behavior is considered abnormal if it occurs rarely or infrequently in the general population. This definition lends itself very well to measurement, as researchers and clinicians can administer objective assessments to clients and get accurate measurements of just how far their depression, anxiety, hyperactivity, and so on are from the norm. As such, this definition is often seen as highly scientific.
Unfortunately, several problems are apparent when this model is examined closely. First, who determines how far from the norm is too far from the norm? It is not as if there is a stone tablet handed down from the psychopathology gods that has “Behaviors that are two or more standard deviations from the norm shall be considered abnormal” written on it. Instead, researchers and clinicians make that decision. Often, behaviors are considered “abnormal” if they occur in less than 5% of the population (1.645 standard deviations from the mean), but this is an entirely arbitrary cutoff. Another concern is that the tests that measure one’s deviation are developed from within a particular cultural framework. In other words, there is not an objective, scientific definition of “obsessive-compulsive disorder,” there is only the definition that the researchers developing the measure have (and someone else may not agree with it).
It is also worth noting that when viewing behavior, both sides of the normal curve would be considered “abnormal.” So, according to this model, both someone with very high and very low general anxiety would be considered abnormal. In the real world, though, it is usually only one tail of the curve that is viewed as problematic or a