The Automatic Thoughts Questionnaire (ATQ; Hollon & Kendall, 1980). The ATQ measures depressogenic thought frequency. This measure is commonly used in depression studies examining the impact of cognitive therapy. However, the ATQ-B is a revision to this measure by Zettle and Hayes (ATQ-B, Zettle & Hayes, 1986) aimed at assessing the believability of these depressive thoughts if they occur and it has been used as a proxy measure for defusion in the ACT community. We recommend that you use both subscales; the ATQ-F for frequency of automatic/depressive thoughts and the ATQ-B for believability of (or fusion with) these thoughts. Scoring for the measure is typically a simple sum score for the F sub scale and the B sub scale. The F and B scores can be used in analyses as separate entities and have been shown to be differentially related to outcomes (e.g., frequency of thoughts was not reduced at post treatment but believability of them was reduced) in studies of depression using behavioral interventions.
Reference: Zettle, R. D. & Hayes, S. C. (1986). Dysfunctional control by client verbal behavior: The context of reason giving. The Analysis of Verbal Behavior, 4, 30 38.