A major review in World Psychiatry by Pim Cuijpers and colleagues (2026) examines recent innovations aimed at improving the outcomes and uptake of psychological treatments for mental disorders. The paper highlights the growing importance of transdiagnostic psychotherapy approaches that target common psychological processes across disorders rather than treating each diagnosis separately.

The authors note that comorbidity between depression and anxiety is very high, and that many emotional disorders share overlapping mechanisms. For this reason, they argue that transdiagnostic treatments can offer a more flexible and efficient alternative to diagnosis-specific protocols, reducing fragmentation in care while maintaining effectiveness.

In their review of the evidence, Cuijpers and colleagues identify the Unified Protocol (UP) as the best-established example of a transdiagnostic psychotherapy. They emphasize that the UP is the earliest and most extensively studied model for depression and anxiety, and that a recent meta-analysis of 19 randomized trials found moderate effects compared with waitlist controls and small but significant advantages compared with other active treatments. More broadly, research on transdiagnostic therapies shows substantial effects on both depression and anxiety that are largely comparable to diagnosis-specific CBT.

The authors conclude that while transdiagnostic treatments are not clearly superior to disorder-specific therapies in terms of symptom reduction alone, they offer important practical advantages. They can therefore be helpful in many real-world clinical settings where patients often present with multiple, overlapping problems. Overall, the review positions the Unified Protocol as a scientifically robust model that exemplifies the strengths of the transdiagnostic approach.