Affective Considerations in Anxiety and Depression Comorbidity

Abstract

Generalized anxiety disorder (GAD) and major depressive disorder (MDD) co-occur at rates much higher than chance. Because of overlapping risk factors and higher rates of comorbidity than other anxiety disorders, researchers have proposed reclassifying GAD; one of the most influential proposals calls for GAD and MDD to be classified together as anxious-misery disorders, with the remaining anxiety disorders reclassified as fear disorders. The tripartite model attempts to explain comorbidity of depression and anxiety through positive affect, negative affect, and physiological hyperarousal. However, its theory that low positive affect is exclusive to depression has been questioned – instead, low rates of positive affect are found in all anxiety disorders, especially in GAD. The current study examines positive affect in anxious-misery symptoms and fear symptoms to determine if positive affect varies in a manner consistent with the model and if it supports the reclassification of mood and anxiety disorders. Using a sample of adolescents and young adults (n=904), correlations and linear regression were conducted on positive affect and mood disorder symptoms. Symptoms of depression, generalized anxiety, social anxiety, and panic disorder each had significant negative correlations with positive affect. A regression analysis controlling for the overlapping variance among symptoms demonstrated that depression showed the strongest negative relationship with positive affect, followed by generalized anxiety and social anxiety. There was no significant relationship between positive affect and panic disorder symptoms. These findings support the close relationship between depression and generalized anxiety but also demonstrate that positive affect may not be adequate to differentiate anxious-misery and fear disorders.