Global Distress Factor
Over the last two decades, it has become clear that virtually all patient self-report outcome measures commonly used in psychotherapy research are, to a large extent, measuring a common factor, usually referred to as global distress.
The most popular outcome measures are highly correlated with one another. For example, Brophy et al (1988) found that the The Symptom Checklist-90-R sub-scales all load on a common factor, and likewise correlate with similar scales from other measures. Doefler et al (2002) found that the OQ-45 and the BASIS-32 are highly correlated with one another. Miller et al (2003) likewise found that the Outcome Rating Scale correlates with the OQ-45. Enns et al (1998) performed factor analyses on the Beck Depression Inventory and the Beck Anxiety Inventory. To quote from the abstract...
"However, the parameter estimate was very high (0.784) and a unidimensional, single-factor model of negative affectivity approached the criteria for good fit. It was concluded that the Beck Anxiety and Depression Inventories assess distinct anxiety and depression phenomena to a limited extent when used in a clinically depressed sample."
What does Global Distress correlate with?
-Eating Disorder Symptoms
-Quality of Relationships
-Day to Day Functioning