Effect of a One-Session ACT Protocol in Disrupting Repetitive Negative Thinking: A Randomized Multiple-Baseline Design

IACT, RFT, Worry, Rumination, Single-case experimental designdentified as a transdiagnostic process implicated in the onset and maintenance of emotional disorders. Recent research suggests that both forms of RNT are particularly counterproductive experiential avoidance strategies because individuals usually engage in them as the first response when experiencing distress. This leads to the extension of relational networks and discomfort as well as to the engagement in additional experiential avoidance strategies that soon provoke meaningful life limitations. The current study analyzed the effect of a one-session Acceptance and Commitment Therapy (ACT) protocol in reducing RNT through altering the discriminative functions of the most relevant self-related thought to engage in RNT. We used a two-arm, randomized multiple-baseline design. Participants were 11 adults experiencing RNT that had interfered with their functioning for at least the last six months and were suffering from moderate emotional symptoms. Four RNT-related measures were administered: a daily RNT self-register, measures of pathological worry, rumination (brooding), and frequency of negative thoughts. Nine participants showed significant reductions in at least three out of the four RNT measures during the 6-week follow-up. Effect sizes were very large in all RNT-related measures and in emotional symptoms, experiential avoidance, cognitive fusion, and valued living. Testing an ACT version for emotional disorders specifically focused on disrupting RNT is warranted. How to cite: Ruiz FJ, Riaño-Hernández D, Suárez-Falcón JC, & Luciano C (2016) Effect of a One-Session ACT Protocol in Disrupting Repetitive Negative Thinking: A Randomized Multiple-Baseline Design. International Journal of Psychology and Psychological Therapy, 16, 213-23