The effect of anxiety on change in depression in cognitive therapy for major depression

The presence of anxiety in individuals with major depression is generally thought to lead to impaired treatment response. However, findings on the effect of anxiety on treatment for depression have been mixed. In this study, we present a preliminary finding (Study 1) showing that high anxiety level at intake was associated with quicker rate of change in cognitive therapy for major depression. The purpose of the current study is to replicate the preliminary finding (Study 2) and to explore potential mechanisms. Participants in both studies were patients treated for major depression at the Beck Institute of Cognitive Therapy and Research. Results showed a trend for higher intake anxiety to increase rate of change in Study 2. In both studies, subscales of the BAI that measure physiological anxiety symptoms appeared to drive the effect. Higher anxiety was associated with greater stressful perceptions of everyday events and lower coping efficacy in Study 1. High anxiety also predicted sudden gains in Study 1, but not in Study 2. In Study 2, change in anxiety in one session predicted change in depression in the next session, suggesting that at least for some patients, a change in anxiety precedes a change in depression. These results are unexpected and have implications for cognitive therapy, co-occurring conditions, and the nature of anxiety. Preliminary investigation of mechanisms suggests that the "energy" provided by physiological symptoms of anxiety might help overcome the vegetative symptoms of major depression. Other mechanisms might involve alternate interventions strategies and the possibility that depression is secondary to anxiety. These results are preliminary and must be interpreted with caution. Extension of these findings is important, with a particular emphasis on the mechanisms.