A brain injury (e.g. stroke, traumatic brain injury) occurs all of a sudden and is often followed by complex neurological and psychological consequences. These consequences do not only affect the patients with the brain injury as Muriel Lezak already stated in 1988: "Brain damage is a family affair". Symptoms of depression and anxiety as well as an increased caregiver burden are common, but there is still a lack in randomized controlled trials that investigate the efficacy of multicomponent interventions for informal caregivers. The main aim of the current study is to close this scientific gap with an innovative method for this special population. OSCAR (the Internet-based supportive coaching) uses the Internet as a communication- and information brokering medium and is designed as a "guided-self-help tool" where a qualified therapist individually supports every participant. The key objective is to investigate the feasibility, acceptance and efficacy of an Internet-based supportive coaching (OSCAR) for informal caregivers of adult individuals with an acquired brain injury. It is expected that the Internet-based supportive coaching (OSCAR) leads to a better coping of emotional distress reactions and caregiver burden.