Internet-based acceptance and commitment therapy for bipolar disorder: A randomized controlled pilot trial

Gulimire Isak; Manqi Cai; Zhihui Zhang; Zhihong Ren

doi:10.1016/j.psychres.2025.116608

Internet-based acceptance and commitment therapy for bipolar disorder: A randomized controlled pilot trial

Psychiatry Res. 2025 Jun 22:351:116608. doi: 10.1016/j.psychres.2025.116608. Online ahead of print.

Authors

Gulimire Isak¹, Manqi Cai¹, Zhihui Zhang¹, Zhihong Ren²

Affiliations

¹ Key Laboratory of Adolescent Cyberpsychology and Behavior (CCNU), Ministry of Education, Wuhan 430079, PR China; Key Laboratory of Human Development and Mental Health of Hubei Province, School of Psychology, Central China Normal University, Wuhan 430079, PR China.
² Key Laboratory of Adolescent Cyberpsychology and Behavior (CCNU), Ministry of Education, Wuhan 430079, PR China; Key Laboratory of Human Development and Mental Health of Hubei Province, School of Psychology, Central China Normal University, Wuhan 430079, PR China; School of Psychology, Liaoning Normal University, Dalian 116029, PR China. Electronic address: ren@ccnu.edu.cn.

PMID: 40570697
DOI: 10.1016/j.psychres.2025.116608

Abstract

Internet-based Acceptance and Commitment Therapy (iACT) offers a promising, scalable intervention format for individuals with bipolar disorder (BD), yet its feasibility and preliminary efficacy remain underexplored. This pilot randomized controlled trial evaluated the acceptability, feasibility, and initial efficacy of a 7-day self-guided iACT program delivered via a secure, mobile-responsive platform. Seventy individuals were screened, of whom 60 clinically stable adults with BD (aged 18-60) met eligibility criteria and were randomized to either the iACT group (n = 30) or an active control group receiving digital psychoeducation (n = 30), yielding a recruitment rate of 85.7 %. Retention at post-intervention was 100 %. In the iACT group, 93.3 % (28/30) met predefined adherence criteria (completion of ≥5 modules), indicating high intervention engagement. Between-group comparisons using ANCOVA (controlling for baseline scores) showed that the iACT group demonstrated significantly greater improvements in psychological flexibility (AAQ-II), reduced cognitive fusion (CFQ), improved social functioning (SDSS), and lower manic symptoms (YMRS), with small-to-medium effect sizes (Cohen's d = -0.28 to -0.59). Differences in depression symptoms (SDS) approached statistical significance (p = .054). High recruitment, retention, and adherence support the feasibility of brief iACT for BD. Preliminary efficacy signals justify a definitive RCT to evaluate clinical effectiveness.

Keywords: Acceptance and commitment therapy; Bipolar disorder; Cognitive Fusion; Depression; Internet-based intervention; Mania; Pilot trial; Psychological Flexibility.