Congenital heart disease (CHD) is associated with daily stressors and functional impairments that can cause negative emotions. Emotion regulation abilities may determine whether people with CHD develop psychopathology or adapt to the illness-related regulatory demands. This three-arm randomized clinical trial evaluates the efficacy of emotion regulation interventions in individuals with CHD.

Patients with CHD over 18 years will be randomly assigned to a CHD-specific web-based emotion regulation intervention, a general web-based emotion regulation intervention, or a waitlist control group with delayed intervention access (8 weeks). The interventions are based on cognitive behavioral therapy, including everyday emotion regulation exercises and psychoeducation via video and audio files. Four and eight weeks after baseline, emotion regulation, well-being, depression, anxiety, perceived stress, life satisfaction, and illness identity will be assessed.

Both interventions are expected to improve emotion regulation abilities, well-being, depressive symptoms, anxiety, perceived stress, life satisfaction, and illness identity four and eight weeks after baseline compared to the waitlist control group. The disease-specific intervention is hypothesized to be superior as it targets everyday emotional problems in CHD patients.

Background: Congenital heart disease (CHD) is associated with significant everyday stressors and impairments in functioning that can induce various negative emotions such as fear, anger, or sadness. When faced with negative emotions caused by the chronic illness, emotion regulation abilities might be central for determining whether individuals with CHD develop symptoms of psychopathology or successfully adjust to the illness-related regulatory demands. Therefore, training emotion regulation abilities offers a promising approach to enhancing psychological well-being in individuals affected by CHD. As patients with CHD face specific challenges, disease-specific emotion regulation interventions may be beneficial in promoting successful adjustment to the condition. Nevertheless, no studies have been conducted to test the effectiveness of emotion regulation interventions for individuals with CHD.

Method: The present three-armed randomized clinical trial evaluates the efficacy of web-based emotion regulation interventions in individuals with CHD. Patients with CHD over 18 years old will be randomly assigned to:

1. A CHD-specific web-based emotion regulation intervention.
2. A general web-based emotion regulation intervention.
3. A waitlist control group with delayed intervention access (8 weeks).

The interventions are conducted via mobile phone or desktop browsers and are based on cognitive behavioral therapy, including everyday emotion regulation exercises and psychoeducation via video material and audio files. Four and eight weeks after baseline, emotion regulation abilities, well-being, depression, anxiety, perceived stress, life satisfaction, and illness identity will be assessed as outcome measures.

Hypotheses: Both interventions are expected to enhance emotion regulation abilities four and eight weeks after baseline compared to the waitlist control group. In addition, the interventions are hypothesized to improve well-being, depressive symptoms, anxiety, perceived stress, life satisfaction, and illness identity. The disease-specific intervention is assumed to be superior to the general emotion regulation intervention as it targets everyday emotional challenges in CHD patients.

Inclusion criteria:

• sufficient German language skills (C1)
• permanent internet access during the study period
• diagnosis of a congenital heart disease
• ≥ 18 years of age

Exclusion criteria:

• incapacity to provide informed consent
• acute suicidality

The group allocation variable will be masked during the data analyses to minimize possible bias concerning the statistical procedure. For this purpose, an independent researcher will delete all information in the dataset indicating the group allocation. Therefore, the evaluator does not know which expression of the group variable represents the CHD-specific intervention, the general intervention, or the waitlist control group.