Differential patterns of physical symptoms and subjective processes in generalized anxiety disorder and unipolar depression.

Given the substantial comorbidity between generalized anxiety disorder (GAD) and unipolar depressive disorders (UDDs), some have suggested that these disorders be combined in future editions of the DSM. However, decisions regarding nosology should not only account for current manifestations of symptom profiles, but also the potential diagnostic utility of associated characteristics, which, given past research, may suggest greater distinctiveness between these disorder classes. In the present investigation, we examined the role of one-item indices of physical, emotional/motivational, and cognitive symptoms in differentiating GAD from UDDs. We assessed these symptoms with one-item measures in order to provide an initial examination of the viability of these constructs as diagnostic criteria. In Study 1, in an unselected college sample, muscle pains and aches, gastrointestinal symptoms, emotion intensity, and intolerance of uncertainty were associated with GAD symptoms; conversely, low positive affect was associated with UDDs symptoms. In Study 2, we extended these findings to a clinical population and found that muscle pains and aches, positive affect, goal motivation, emotion intensity, and intolerance of uncertainty were higher in GAD than in UDDs. Copyright 2009 Elsevier Ltd. All rights reserved.