Abstract: The present invention is a medical treatment system using an information processing terminal and an information processing network, and a method using said system, wherein the objective of the invention is to provide: a system that performs optimal medical treatment to a patient on the basis of a diagnostic cross-sectional assessment and/or a disease-specific assessment, such that treatment using process-based CBT is possible; and a method using said system. Toward this end, this system (100) has: a block (10A1: diagnostic cross-sectional assessment part) having a function for, while using normal lifestyle date, assessing the degree to which a patient is adaptively behaving, or non-adaptively behaving, in response to psychosocial issue, lifestyle adaptation, stress, etc.