A series of meta-analyses points to the benefits of different psychotherapy approaches in the treatment of persons with schizophrenia such as psycho-educational family interventions or cognitive behaviour therapy for psychosis. However, the advantages of these specific psychotherapeutic interventions as compared to non-specific supportive interventions are moderate. This challenges the validity of the presumed specific therapeutic ingredients.

To analyse the significance of specific therapeutic ingredients of evidence-based psychotherapy approaches for schizophrenia all efficacy studies with component control designs were identified by systematic electronic searches. Subsequently, moderator analyses of the standardized weighted effect sizes differences between psychotherapy approaches with different therapeutic components were performed. The effect size differences were integrated by transforming them into weighted mean point-biserial correlations between single therapeutic components and outcome variables. Furthermore, studies relating common factors such as therapeutic alliance or self-efficacy expectations of patients with outcome were searched, and weighted mean Pearson's correlations between common factors and outcome variables were calculated.

The findings indicate that specific therapeutic components such as psycho-education, cognitive restructuring or skills training represent key therapeutic ingredients of evidence-based psychotherapy for schizophrenia. However, also common factors such as positive therapeutic relationship, changing expectations for self-efficacy or successful mastery efforts are associated with positive outcomes.

There is an urgent need to dismantle the actual therapeutically active components in order to promote the targeted, personalized and, thereby, efficient implementation of evidence-based psychotherapy approaches for persons with schizophrenia in routine care.