Determining the effectiveness of cognitive behavioral therapy interventions based on the transdiagnostic approach in the treatment of common mental health problems: Presenting an experience from the Islamic Republic of Iran.

This trial recommends that the transdiagnostic CBT approach can be effective in improving common mental health problems and functions among individuals by trained general healthcare providers in the primary healthcare system. The results can be more useful in decision making when defining the process of providing mental healthcare in the National Primary Healthcare System.