[Rehabilitation success after psychosomatic rehabilitation as a function of psychotherapy dose]

Increasing the effectiveness of psychosomatic rehabilitation by prolonging the treatment is a subject of controversial debate. The number of sessions over time defines the dosage in psychotherapy. While the dose-response model assumes an optimal therapy dose, the good-enough level model assumes a correlation of the rate of change with the total sessions. A randomized control group study was conducted to investigate the extent to which an adaptive therapy concept with a two-week intensive phase and early intervention could increase rehabilitation success.

A total of 494 rehabilitants between the ages of 21 and 64 (47% women) who completed a classical or an integrative psychosomatic rehabilitation at the Rehazentrum Oberharz between 2020 and 2022 were analysed. Rehabilitation success was mapped by the Reliable Change Index of individual symptom reduction (depression severity or psychological and somatoform disorders) and as a socio-medical parameter (physician's assessment of potential work ability (WA) after two weeks). Two-factorial ANOVAs and hierarchical binary logistic regressions were calculated, and sick leave before rehabilitation was statistically controlled.

Dosage showed no effect on symptom reduction (p = 0.29) and potential WA after two weeks (p = 0.90). However, when stratified by disease severity, there was a mean effect of dosage (p = 0.05) and twice the probability of WA after two weeks (odds 2.13; p = 0.01) for those with mild disease at the start of measure (p = 0.05).

In the early stages of an affective disorder, early and intensified intervention can counteract the chronification of mental disorders.