One of the main drawbacks of computer-assisted psychology tools developed up to now is related to the real time customisation and adaptation of the content to each patient depending on his/her activity. In this paper we propose a new approach for mental e-health treatments named Intelligent e-Therapy (eIT) with capabilities for ambient intelligence and ubiquitous computing. From a technical point of view, an eIT system is based on four fundamental axes: ambient intelligence for capturing physiological, psychological and contextual information of the patient; persuasive computing for changing/reinforcing behaviours; ubiquitous computing for using the system at any place, and at any time; and multiple technological platforms support. (Contains 1 figure.)