The Effects of Online Mindfulness-Based Intervention on Posttraumatic Stress Disorder and Complex Posttraumatic Stress Disorder Symptoms: A Randomized Controlled Trial With 3-Month Follow-Up

OBJECTIVES: Mindfulness-based interventions have recently been shown to be a promising option for treating posttraumatic stress. The current study aimed to investigate the effects of an online mindfulness-based intervention on ICD-11 posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) symptoms at a 3-month follow-up. METHODS: An RCT design with three measurement points (pre-intervention, post-intervention, and 3-month follow-up) was used to investigate the effects of an 8-week online mindfulness intervention. In total, 53 traumatized young adults (M(age) = 23.21, SD(age) = 2.81; 84.9% female) participated in the study: 17 in the intervention group and 36 in the waiting list control group. RESULTS: Intervention group and waiting list control group comparison revealed that the intervention was effective for reducing CPTSD disturbances in self-organization symptoms (d = −0.84 [−1.44; −0.24]), specifically, negative self-concept (d = −0.66 [−1.25; −0.07]) and disturbances in relationships (d = −0.87 [−1.47; −0.27]), at 3-month follow-up. There were no between-group effects for PTSD symptoms from pre-test to follow-up. CONCLUSION: This is one of the first RCT studies to report follow-up effects of an online mindfulness-based intervention for ICD-11 PTSD or CPTSD symptoms. Our study yielded that the effects of mindfulness-based internet intervention on CPTSD symptoms tend to retain over time. TRIAL REGISTRATION: This study was registered with ClinicalTrials.gov (NCT number: NCT04333667; https://clinicaltrials.gov/ct2/show/NCT04333667). Registered April 3, 2020.