The aim of the study is the examination of brain plasticity on on affective symptoms after neuromodulation with fMRI (functional magnetic resonance imaging) neurofeedback. During the fMRI neurofeedback training, patients with depression as well as patients with schizophrenia are trained to consciously regulate the activity of areas which are associated with the cognitive reappraisal of emotional stimuli.The aim is to improve the patients' subjective emotional processing and perception in everyday life as well as to investigate the impact of neurofeedback on resting-state networks in the brain. Healthy participants will be investigated as control group.

The ability to regulate emotions is a central element of mental health that is significantly affected in various psychiatric disorders. Its importance for development and maintenance of depressive symptomatology has been widely shown; e.g. patients with depression have a significantly reduced ability to regulate emotions in response to negative stimuli. However, emotion regulation abilities may pose as an important resilience factor that can counteract the development of depressive symptoms. The loss of the ability to regulate emotions is not only observed in depression, but is also a core factor in negative symptoms of schizophrenia.

Cognitive reappraisal training is an established method to improve emotion regulation. The cognitive reappraisal of a stimulus or situation works by reinterpreting the emotional stimulus or situation and can change the course of the emotional response. Over the last years this form of cognitive reappraisal training has become a standard approach in the treatment of affective disorders.

The prefrontal cortex (PFC) plays an important role in emotion regulation. In line with this it has been shown that patients with reduced emotion regulation ability display impaired functioning of the PFC. Aim of the study is to train patients to consciously upregulate activity in the PFC and thereby to increase emotion regulation ability. On the behavioral level this is expected to correlate with a reduced experience of negative mood. In order to regulate the PFC, participants are instructed to use cognitive reappraisal strategies. Cognitive reappraisal is an effective and well-investigated strategy to improve emotion regulation and is a standard cognitive-behavioral psychotherapeutic intervention. During cognitive reappraisal the meaning of a picture is reinterpreted in order to reduce the emotional reaction. Recent fMRI studies have shown that cognitive reappraisal is associated with an increase in prefrontal activity and a decrease of amygdala activation.

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.

Inclusion Criteria:

• Depression according to ICD-10 (F32.x, F33.x, F31.3 or F34.x); Schizophrenia according to ICD-10 (F2x); or healthy subjects
• Fluent German language skills

Exclusion Criteria:

• any contraindication to MRI examination or claustrophobia
• pregnant or lactating women
• acute suicidal tendency
• persons incapable of giving consent