Brief scales for the measurement of target variables and processes of change in cognitive behaviour therapy for major depression, panic disorder and social anxiety disorder.

BACKGROUND: The measurement of process variables derived from cognitive behavioural theory can aid treatment development and support the clinician in following treatment progress. Self-report process measures are ideally brief, which reduces the burden on patients and facilitates the implementation of repeated measurements. AIMS: To develop 13 brief versions (3-6 items) of existing cognitive behavioural process scales for three common mental disorders: major depression, panic disorder, and social anxiety disorder. METHOD: Using data from a real-world teaching clinic offering internet-delivered cognitive behavior therapy (n=370), we drafted brief process scales and then validated these scales in later cohorts (n=293). RESULTS: In the validation data, change in the brief process scales significantly mediated change in the corresponding domain outcomes, with standardized coefficient point estimates in the range of -0.53 to -0.21. Correlations with the original process scales were substantial (r=.83-.96), internal consistency was mostly adequate (α=0.65-0.86), and change scores were moderate to large (|d|=0.51-1.18). For depression, the brief Behavioral Activation for Depression Scale-Activation subscale was especially promising. For panic disorder, the brief Agoraphobic Cognitions Questionnaire-Physical Consequences subscale was especially promising. For social anxiety disorder, the Social Cognitions Questionnaire, the Social Probability and Cost Questionnaire, and the Social Behavior Questionnaire-Avoidance and Impression Management subscales were all promising. CONCLUSIONS: Several brief process scales showed promise as measures of treatment processes in cognitive behaviour therapy. There is a need for replication and further evaluation using experimental designs, in other clinical settings, and preferably in larger samples.