Mobile mental health applications are regarded as a promising solution to meet increasing demands in mental health treatment. They are used to treat mental disorders and can only be successful if the treatment population accepts and appreciates them. This research analyses the acceptance of mobile mental health applications by young adults in Germany in order to identify inhibiting factors regarding their use. To describe people's intentions to use mobile treatment applications, an extended version of the technology acceptance model (TAM) is applied. In the past, TAM has already been used to access the acceptance and adaption of new medical applications. The findings suggest that knowledge about the existence and clinical effectiveness of mobile mental health applications are considerably low. Even though, mobile applications are considered easy to use, their effectiveness in treating mental disorders is questioned by the young adults. Furthermore, concerns that personal information can potentially be revealed arise. This can additionally inhibit the acceptance of these applications. To improve the acceptance and increase future usage, mobile mental health applications should be promoted as a supporting tool that is always available for anyone and can facilitate mental treatment.