Dimensional Latent Factor Structure of Psychopathology in Adults With Chronic Illness

The goal of the present study was to determine if the internalizing and externalizing model of psychopathology is applicable in a sample of adults with chronic illness. Confirmatory factor analyses were used to examine the factor structure of internalizing and externalizing symptoms in a sample of adults (N = 172) with a unique chronic physical health condition (postural orthostatic tachycardia syndrome; POTS) and in a sample of adults without any chronic illness diagnoses (N = 199). Measurement invariance was used to compare levels of internalizing and externalizing symptoms across samples. Confirmatory factor analyses suggested that psychological distress in individuals with chronic illness can be effectively characterized by an internalizing dimension composed of distress and fear subcomponents as well as an externalizing dimension. Measurement invariance testing reached adequate levels of fit, allowing for examination of latent means; individuals with chronic illness had higher scores on the internalizing dimension and lower scores on the externalizing dimension than healthy controls. Regression analyses suggested that among those with a chronic illness, internalizing symptoms were significantly, negatively related to acceptance of illness and higher health-related quality of life. Findings suggest that assessing internalizing symptoms broadly may allow for better identification of chronically ill individuals experiencing psychological distress than a focus on categorical diagnoses. However, professionals also need to be aware of the overlap between physical and psychological symptoms in adults with chronic illnesses in order to avoid inaccurate diagnoses. Public Significance Statement This study supports the use of broad, dimensional, symptom-based measures to assess for psychological distress in individuals with chronic illnesses. Individuals with chronic physical illnesses experience more symptoms related to mood and anxiety and fewer problems relating to impulsive and problematic behavior than individuals without chronic illnesses.