Influence of motivational placebo-related factors on the effects of exercise treatment in depressive adolescents

• Published in: European child & adolescent psychiatry 2022-07, Vol.31 (7), p.1-14
• Main Authors: Wunram, Heidrun Lioba, Hamacher, Stefanie, Oberste, Max, Neufang, Susanne, Belke, Luisa, Jänicke, Franziska, Graf, Christine, Schönau, Eckhard, Bender, Stephan, Fricke, Oliver
• Format: Article
• Language: English
• Subjects: Adolescent; Adolescents; Affect; Change agents; Child; Child & adolescent psychiatry; Child and Adolescent Psychiatry; Childhood depression; Children; Conditioning; Enjoyment; Exercise; Exercise Therapy; Humans; Medicine; Medicine & Public Health; Mental depression; Motivation; Neurobiology; Original Contribution; Physical activity; Physical fitness; Physical training; Placebos; Psychiatry; Sports; Teenagers
• ISSN: 1018-8827; 1435-165X; 1435-165X
• DOI: 10.1007/s00787-021-01742-5

Recent meta-analyses reveal a moderate effect of physical activity (PA) in the treatment of adolescent depression. However, not only the underlying neurobiological mechanisms, also the influences of placebo-related motivational factors (beliefs and expectancies in sporting, enjoyment and prior sports experiences), are still unclear. Based on the data of our prior study “Mood Vibes”, we hypothesized that placebo-inherent factors like positive prior sports experiences and motivational factors, (positive beliefs, expectancies, and enjoyment related to PA), would increase the effects of an add-on exercise-therapy in juvenile depression. From 64 included depressed adolescents, 41 underwent an intensive add-on PA-therapy. Motivational factors were assessed using sport-specific scales. The changes in depression scores under treatment were rated by self-rating scale (German “Childhood Depression Inventory”, (DIKJ)). A mixed model for repeated measures (MMRM) was used to analyze the effects of the different motivational variates on DIKJ. While prior sports experiences had no impact, motivational factors showed a significant effect on PA-induced changes in DIKJ scores ( p  = 0.002). The demotivated participants improved less, whereas it was sufficient to be neutral towards sporting to benefit significantly more. Motivational placebo-related factors (beliefs, expectancies and enjoyment regarding PA) affected the outcomes of an exercise treatment in depressed adolescents. Yet, a neutral mindset was sufficient to profit more from PA. Prior sporting in the sense of positive conditioning and as a protective factor did not play a role. Knowledge about these influences could in a second step help to develop tailored therapies.