BACKGROUND: Healthcare workers (HCWs) face substantial daily work-related pressures, leading to frequent reports of depression, anxiety and post-traumatic stress disorder (PTSD) symptoms. OBJECTIVE: To compare the effects of Self-Help Plus in its digital version Doing What Matters in Times of Stress (DWM) to an equally structured activity in reducing anxiety and/or PTSD symptoms among HCWs. METHODS: We compared the proportion of participants with moderate-to-severe anxiety (General Anxiety Disorder Scale
GAD-7 ≥10) and/or PTSD symptoms (Impact of Event Scale-Revised (IES-R)) ≥26) between DWM and the alternative activity. We used an intention to treat analysis and performed χ FINDINGS: At 14 weeks, 14.5% of DWM and 27.6% of control participants showed at least moderate anxiety and/or PTSD symptoms (χ CONCLUSIONS: DWM is a promising strategy to reduce moderate-to-severe PTSD and/or anxiety symptoms in HCWs. Compliance is crucial to ensure efficacy. CLINICAL IMPLICATIONS: DWM is a scalable digital tool that could be considered as an intermediate or complementary intervention for distressed HCWs.