The new technique of real-time fMRI enables subjects to influence their brain activity in certain areas based on neurofeedback. Ongoing brain activity as measured by fMRI is reported to the participants in real time via brain computer interface (BCI). In order to influence brain activity, mental strategies are usually recommended to the participants that have been shown to increase activity in the respective area. Due to the identification of contingency between feedback and mental strategies participants are able to control their own brain activity consciously. It has been shown that psychiatric symptomatology can be improved using this non-invasive technique. In the current study it will be investigated whether neurofeedback of the PFC has a positive influence on affective symptoms in patients with depression and schizophrenia, respectively. In detail it is researched whether the upregulation of activity in the PFC can lead to an increase in subjective well-being. Two groups of patients (depression (N=40) and schizophrenia (N=40)) as well as a group of healthy participants will receive neurofeedback-training of the PFC. Aim of the study is an improvement of depressive (or negative) symptoms as well as the investigation of the impact of neurofeedback on resting-state networks in the brain.