In both primary care medicine and health psychology, the literature reflects a growing interest in the most efficient ways to implement the integrative model of health care, including recognition of the primary care provider as the gatekeeper of mental health services. However, less work has been done addressing the specific challenges to implementation such as how primary care providers refer patients for mental health services. Specifically, little is known about how medical providers assess the need for mental health services, or about their working theoretical paradigm for understanding the relationship between physical and psychological symptoms.

This study investigated the referral process of medical providers in primary care as a means to understand the barriers to integrating physical and mental health care. A chart review was conducted on 119 primary care patient charts to track the referral practices of PCPs by extracting several variables to highlight the presence of referrals made using integrative criteria. Following, six PCPs were interviewed using semi-structured qualitative interviews to obtain more information about how they conceptualized their patients' symptoms and made subsequent referrals to mental health services.

Results showed that patients presented their problems to their PCP with mixed symptomology. That is, while patients initially presented to their PCPs with physical complaints, patients endorsed a large number of both physical and psychological symptoms during the medical visit. PCPs recognized a limited psychosomatic connection between their patients' physical and psychological symptoms. PCPs generally utilized a diagnostic process that implicitly splits physical and psychological processes, and therefore generally conceptualized their patients' physical symptoms as being caused by (rather than intricately connected to) psychological ones. As a result, PCPs almost always referred their patients to mental health services for psychiatric disorders, rather than related physical ones.