Early developments in general change mechanisms predict reliable improvement in addition to early symptom...

General change mechanisms (GCMs) have been shown to predict treatment outcome in cognitive behavioral therapy (CBT). Early changes in GCMs (early-change-GCMs) and in symptom severity were also linked to treatment outcome, but evidence is still limited. We investigated whether early-change-GCMs from patients' and therapists' perspectives in addition to early changes in symptom severity predict treatment outcome. Data from a university-based outpatient clinic was analyzed (N = 911 completers). Most treatments were provided by therapists in CBT training. Outcomes were symptom severity and life satisfaction. Continuous post-treatment scores and categories of reliable improvement (improved vs. not improved) were investigated. Some patient-rated early-change-GCMs and early changes in symptom severity proved to be predictors for continuous outcomes (p < .05) in symptom severity and life satisfaction. In addition, some patient-rated early-change-GCMs predicted reliable improvement in life satisfaction. By contrast, therapist-rated early-change-GCMs and early symptom severity change predicted reliable improvement in symptom severity. Early-change-GCMs explained between two and four percent additional variance in outcomes. Thus, it is important to consider early changes in GCMs in addition to early changes in symptom severity in routine monitoring.