Instruments
The set of questionnaires included the State-Trait-Cheerfulness-Inventory (STCI-T and -S) [Cheerfulness was measured using the STCI-T and -S [Symptom burden and well-being were assessed with the MIDOS [Life satisfaction was measured with the SWLS [The distress thermometer consists of a scale from 0 to 10 where participants can mark their level of stress in the current situation [Saliva samples were collected by a study nurse by having the patient chew on a cotton wool roll (Salivette® Sarstedt) for at least 60 s. Then the concentration of oxytocin in saliva [The researcher assisted the patients in completing the questionnaires. Depending on their performance level, she read the questions aloud or supervised independent completion.