Introduction: The therapeutic adherence includes those behaviors of the subject that correspond to the recommendations agreed by the health professional. It is a complex phenomenon and determined by several factors. Objective: To analyze the therapeutic adherence and the factors involved, in young people and adults with problematic substance use, from the characterization of users and professionals. Methodology: Ex post-exploratory / descriptive study with mixed design. Two ad hoc questionnaires were applied, clinical histories and an observation grid were used. Participants were 31 users and 6 professionals (psychologists and psychiatrists) of both sexes from a private psychiatric institution. Results:The majority of users adhere to the treatment, especially those of male sex, from 41 to 50 years old, single and with full secondary. They presented social su...