The specificity and mechanism of sudden gains
Sudden gain, a sudden and large drop in symptom severity in one between sessions interval, was first discovered in cognitive-behavioral therapy (CBT) for depression (Tang & DeRubeis, 1999). Since then, sudden gains have been found in several different therapies for depression, and their mechanisms seem to be associated with specific therapy factors. The present paper investigated further into the specificity and mechanism of sudden gains through two studies. In study 1, we examined to what factors the patients attribute their sudden gains, and when sudden gains occur (within the pregain session vs. within the between-session interval following the pregain session). Consistent with prior study based on observers' ratings, the patients in the sample also attributed their sudden gains to behavior changes. The patients also did not attribute the majority of sudden gains to positive life events. Patients' mood ratings at the beginning and end of session also show that sudden gains occurred in the between-session interval following the pregain session. Study 2 investigated sudden gains in CBT for panic disorder at a university training clinic. The results suggest that sudden gains also exist in CBT for panic disorder, and they appear very similar to those found in CBT for depression. The findings offer empirical support to the specific mechanism of CBT, and they suggest that sudden gains might be a general phenomenon in the treatment of affect disorders.