Pathological Smartphone Use (PSU) is an emerging phenomenon that needs to be understood. Although there are extensive studies in Pathological Internet Use (PIU) empirical research appears to be still insufficient. It is important to note that Media System Dependency (MSD) Theory assumed that social system and media system as the factors to explain Pathological Internet Use (PIU).The main objective of this research is to extend the MSD Theory with a new construct called personality system and examine its effect on PSU. In this study, the target respondents are the Millennial cohort who are born between 1981 and 1996, often early adopters of new technologies as well as extensive users of the Smartphone. The preliminary phase of the research uses a qualitative approach the gain observable facts which is followed by quantitative data analysis aimed at testing the plausibility of the proposed model among urban Millennial (age 20 - 35 years old). The research introduced an integrative MSD model and it is suggested personality is the main factor behind smartphone pathology phenomenon.