This paper presents a mobile treatment system developed as part of the FP7 ICT4Depression project. The project targets the efficient treatment of minor and major depression. To this end, treatments that have traditionally been administered via relatively simple web-based interfaces, have been translated for use on a smart phone. The delivery of the treatments is supported by an evidence-based approach to patient progression and treatment adherence monitoring. The mobile system consists of a graphical user interface, biomedical sensors to measure the patient's affective state, a medication adherence system, an activity monitor and a server based reasoning system to combine the various sensor data streams and obtain abstracted information relating to patient status and progression, thereby allowing for appropriate feedback and advice for both patient and medical staff.