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

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.

Whole body vibration added to treatment as usual is effective in adolescents with depression: a partly randomized, three-armed clinical trial in inpatients.

There is growing evidence for the effectiveness of exercise in the treatment of adult major depression. With regard to adolescents, clinical trials are scarce. Due to the inherent symptoms of depression (lack of energy, low motivation to exercise), endurance training forms could be too demanding especially in the first weeks of treatment. We hypothesized that an easy-to-perform passive muscular training on a whole body vibration (WBV) device has equal anti-depressive effects compared to a cardiovascular training, both administered as add-ons to treatment as usual (TAU). Secondly, we presumed that both exercise interventions would be superior in their response, compared to TAU. In 2 years 64 medication-naïve depressed inpatients aged 13-18, were included. Both exercise groups fulfilled a supervised vigorous training for 6 weeks. Depressive symptoms were assessed by self-report ("Depressions Inventar für Kinder und Jugendliche"-DIKJ) before intervention and after weeks 6, 14 and 26. Compared to TAU, both groups responded earlier and more strongly measured by DIKJ scores, showing a trend for the WBV group after week 6 (p = 0.082). The decrease became statistically significant for both intervention groups after week 26 (p = 0.037 for ergometer and p = 0.042 for WBV). Remission rates amounted to 39.7% after week 6 and 66% after week 26, compared to 25% after week 26 in TAU. These results provide qualified support for the effectiveness of exercise as add-on treatment for medication-naïve depressed adolescents. The present results are limited by the not randomized control group.