Читать книгу Abnormal Psychology - William J. Ray - Страница 178

Technically, when an individual is seen to have more than one disorder at the same time, the disorders are referred to as comorbid. In the National Comorbidity Survey, a large number of individuals with one disorder were found to have one or more additional diagnoses (Kessler et al., 1994). For example, individuals with generalized anxiety disorder will often also show symptoms of depression. Further, these two disorders have overlapping genetic and environmental risk factors (Kendler, Neale, Kessler, Heath, & Eaves, 1992). The number of diagnoses found in the National Comorbidity Survey was associated with the severity of the symptoms. This has suggested to researchers that there exists a general underlying vulnerability to psychopathology that may be independent of the particular symptoms expressed (Pittenger & Etkin, 2008).

comorbid: descriptive term used when an individual has more than one disorder at the same time

internalizing disorders: disorders that are experienced internally such as anxiety and depression

externalizing disorders: disorders that are manifested in the external world by the person’s behavior, such as conduct disorder (CD), antisocial personality disorder, and other behavior-based disorders

A related approach is to consider which disorders co-occur with one another. In general, two clusters have been found. The first is referred to as internalizing disorders. The focus of these disorders is the inner world of the person, and they include anxiety and depression. The second cluster is referred to as externalizing disorders. The behavioral focus of these disorders is the external environment of the person. These disorders include conduct disorder, oppositional defiant disorder, antisocial personality disorder, substance use disorder, and in some studies attention deficit/hyperactivity disorder (ADHD). These studies of comorbidity clusters have led scientists to search for common factors such as genetics, brain processes, and environmental risk profiles that might be associated with each cluster. Overall, research has supported the idea that mental disorders can be clustered and that it is possible to identify underlying risk factors (Kendler, et al., 2011).

Given these new perspectives, it is not surprising that with new scientific discoveries the field of mental illness is in flux. In this section, I want to describe the nature of some of the current considerations of how we should approach the field of psychopathology from these larger perspectives. In later chapters of this book, I will describe specific approaches in greater detail.