Depression is a syndrome from which 12% of men and 20% women suffer. Behavioral activation (AC) is a structured and brief psychotherapeutic procedure which has shown its efficacy in the treatment of depression. It follows two objectives: 1. increase engagement in activities associated with feelings of pleasure and/or control; 2. reduce involvement in activities maintaining negative affects or increasing their risk. This psychotherapeutic approach is composed of different tools such as psychoeducation and activities monitoring. After completing a BA program, subjects reported significantly less anxiety and depression symptoms, but studies haven't focussed on the improvement of psychological processes (PP) which are often biased in anxiety and depressive disorders (eg, avoidance and ruminations). This literature review presents PP on which BA could have an impact.