Abstract
INTRODUCTION: A substantial proportion of patients with bipolar disorder experience daily variability in mood that seems associated with poor prognostic factors, including impaired functioning, and increased risk of hospitalisation and relapse. The present SmartBipolar randomised controlled trial (RCT) investigated whether group (1) daily smartphone-based outpatient monitoring and treatment including CBT elements with clinical feedback (intervention group) versus group (2) daily smartphone-based monitoring and treatment with CBT elements without clinical feedback (content was the same as intervention group but without clinical feedback) (control group) or group (3) daily smartphone-based mood monitoring only without CBT elements or other smartphone content (control group), improved mood instability and other clinically relevant patient-related outcomes in patients who have had a bipolar disorder for more than two years, and typically many years. METHODS: This study was a pragmatic, randomised controlled trial with a follow-up period of 6 months. The outcomes were (1) mood instability (primary), (2) questionnaire-based evaluations of quality of life, depressive symptoms, manic symptoms, perceived stress, as well as smartphone-based measures of mood, activity, stress, anxiety, irritability, and sleep. Group differences were quantified using linear mixed models. RESULTS: A total of 201 patients with progressed bipolar disorder were included as part of their specialised outpatient treatment in the Mental Health Services in the Capital Region of Denmark. The trial began in March 2021 with last patient follow-up in July 2025. Intention-to-treat analyses showed no differences in the primary outcome mood instability (difference: 0, 95%CI: -0.16; 0.16, p = 0.98). In addition, there were no differences in other patient-reported outcome measures. LIMITATIONS: This was an unblinded trial. CONCLUSION: There was no positive or negative effects of smartphone-based monitoring and treatment on primary or secondary outcomes in the present trial. CLINICAL TRIALS REGISTRATION: NCT04230421. Registered January, 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40345-026-00418-w.