Six online consultations will take place based on the psychosocial assessment and the initial psychosomatic interview every two weeks, resulting in 300 min in 3 months. A structured, telemedicine-supported, modularized, brief psychosomatic intervention is planned with a focus on psychoeducational elements, promotion of self-management, improvement of illness acceptance, modification of self-monitoring, and learning to cope with altered performance levels. The six modularized telemedical sessions taking into account the specific deficits identified in the psychosomatic evaluation. Within the sessions, starting points are identified with the patients, which the patients can work on independently between the sessions.

Measured with the Hospital Anxiety and Depression Scale (HADS). The HADS questionaire consists of fourteen items pertaining to the two subscales for anxiety and depression. Scores for the anxiety and depression subscale range from 0 to 21, with higher score indicating more severe anxiety or depression. Values can be interpreted as normal from 0-7 points, mild (8-10 points), moderate (11-14 points), and severe (15-21 points).

Measured with the Chalder Fatigue Skala (CFS). The 11-part self-report instrument consists of a total scale and two subscales, physical and psychological fatigue. The maximum total score is 33, with higher scores indicating higher levels of fatigue. The maximum score for physical fatigue is 21 (7 items) and for mental fatigue is 12 (4 items). Additionally, a binary code can be calculated for each of the 11 items (0 and 1 = 0; 2 and 3 = 1) to identify cases of severe fatigue. A total score of 4 or more indicates severe fatigue.

The post-exertional malaise scale (PEM-scale) uses five different 5-point Likert scales to assess the frequency or severity of PEM symptoms and a 7-point Likert scale to assess the duration of PEM evaluate resulting in a maximum score of 46.

The Multidimensional Fatigue Inventory questionaire (MFI-20) is a 20-item self-assessment instrument consisting of five subscales: (1) general fatigue, (2) physical fatigue, (3) decreased activity, (4) decreased motivation, and (5) mental fatigue. Each subscale consists of four items with response options on a five-point Likert scale (1 = yes, that applies, 5 = no, that does not apply). Higher scores indicate higher levels of fatigue

The Bell Disability Scale includes eleven statements about the level of physical function. The scale is rated in increments of 10, from 0 (very severe, constantly bedridden) to 100 (healthy).

The work ability index questionnaire (WAI) contains seven questions concerning work, work ability and health, resulting in a total score ranging from seven to 49, with higher values representing greater work ability.

The Brief Illness Perception Questionnaire (IPQ) assesses cognitive and emotional illness perception. The here used short IPQ contains eight new items as well as part of the causal scale previously used in the IPQ-R. All items except the causal question are rated on a scale of 0 to 10. Five of the items assess cognitive representations of illness: consequences (Item 1), time frame (Item 2), personal control (Item 3), treatment control (Item 4), and identity (Item 5). Two of the items capture emotional representations: concern (item 6) and feelings (item 8). One item assesses the comprehensibility of the illness (Item 7). The causal representation is assessed using an open-response item in which patients are asked to list the three most important causal factors for their illness (Item 9)