Background
Sudden gains are significant symptom improvements occurring between therapy sessions. Approximately 20% of individuals with generalized anxiety disorder (GAD) experience sudden gains during psychotherapy (Deschênes and Dugas in Cogn Ther Res 37:805–811, 2013.
https://doi.org/10.1007/s10608-012-9504-1; Flückiger et al. in J Consult Clin Psychol 89(5):454, 2021.
https://doi.org/10.1037/ccp0000639). This study explores the frequency and impact of sudden gains during a novel cognitive-behavioral treatment (CBT) for GAD—Behavioral Experiments for Intolerance of Uncertainty (Dugas et al. in Behav Ther 53(6):1147–1160, 2022.
https://doi.org/10.1016/j.beth.2022.05.003)—a treatment designed to reduce intolerance of uncertainty via behavioral experiments that expose individuals to uncertainty-inducing situations and help them develop more adaptive beliefs and emotional reactions toward uncertainty (Robichaud et al. in Cognitive behavioral treatment for generalized anxiety disorder: from science to practice, Routledge, London, 2019).
Methods
The study tested three hypotheses: (1) at least 20% of participants would experience a sudden gain, (2) participants with sudden gains would demonstrate greater progress during treatment, and (3) these improvements would persist at 6-month follow-up. Forty-eight (48) adults with primary GAD completed 12 sessions of CBT. Sudden gains were identified using the Penn State Worry Questionnaire—Past Week (PSWQ-PW; Stöber and Bittencourt in Behav Res Ther 36(6):645–656, 1998.
https://doi.org/10.1016/S0005-7967(98)00031-X), which was administered weekly during treatment. GAD symptoms were assessed with the Worry and Anxiety Questionnaire (WAQ; Dugas et al. in Journal de Thérapie Comportementale et Cognitive 11:31–36, 2001) administered at baseline, post-treatment, and 6-month follow-up to track symptom changes over time.
Results
Fifteen participants (31.25%) experienced a sudden gain. Mixed ANOVAs revealed that participants with sudden gains achieved significantly greater symptom reductions from pre- to post-treatment (WAQ [F(1,46) = 4.51, p =.039, partial η2 =.09]). These improvements were sustained at 6-month follow-up (WAQ [F(2,82) = 4.91, p =.01, partial η2 =.11]).
Conclusions
Sudden gains during CBT for GAD are both frequent and impactful. In the context of Behavioral Experiments for Intolerance of Uncertainty, these gains contribute to superior outcomes observed at post-treatment and sustained over the long term. Their mechanisms of action and implications for enhancing treatment efficacy warrant further investigation.