Sudden gains occur in a range of disorders and treatments and are of clinical and theoretical significance if they can shed light on therapeutic change processes. This study investigated the relationship between sudden gains in panic symptoms and preceding cognitive change during cognitive behavioural therapy (CBT) for panic disorder.

Participants with panic disorder completed in session measures of panic symptoms and catastrophic cognitions. Independent samples t-tests were used to compare the post-treatment score of those who met criteria for one or more sudden gain during treatment with those who did not, and to compare within-session cognitive change between pre-sudden gain sessions and the previous (control) session.

Twenty-two (42%) of 53 participants experienced a sudden gain during treatment. Participants demonstrating a sudden gain showed more improvement in panic symptoms from pre- to post-treatment than those without a sudden gain. The within-session cognitive change score in the pre-gain session was significantly greater than in the control session.

Sudden gains occurred in individual CBT for panic disorder and within-session cognitive change was associated with sudden gains. This is consistent with the cognitive model of panic disorder and highlights how sudden gains can help to identify key change processes.

Cognitive behavioural therapy (CBT) for panic disorder encourages patients to learn about and make changes to thoughts and behaviour patterns that maintain symptoms of the disorder. Instruments to assess whether or not patients understand therapy content do not currently exist.

The aim of this study was to examine if increases within specific knowledge domains of panic disorder were related to improvement in panic symptoms following an intensive 2-day panic treatment.

Thirty-nine Veterans enrolled in an intensive weekend panic disorder treatment completed knowledge measures immediately before the first session of therapy and at the end of the last day of therapy. Four panic disorder experts evaluated items and reached consensus on subscales. Subscales were reduced further to create psychometrically sound subscales of catastrophic misinterpretation (CM), behaviours (BE), and self-efficacy (SE). A simple regression analysis was conducted to determine whether increased knowledge predicted symptom change at a 3-month follow-up assessment.

The overall knowledge scale was reduced to three subscales BE (n = 7), CM (n = 13) and SE (n = 8) with good internal consistency. Veterans’ knowledge of panic disorder improved from pre- to post-treatment. Greater increase in scores on the knowledge assessment predicted lower panic severity scores at a 3-month follow-up. A follow-up analysis using the three subscales as predictors showed that only changes in CM significantly contributed to the prediction.

In an intensive therapy format, reduction in panic severity was related to improved knowledge overall, but particularly as a result of fewer catastrophic misinterpretations.