Engel (+1) introduced the biopsychosocial model as an essential framework that enables physicians to appreciate the multiple causality of disease and the need for a comprehensive approach to patient care. Authors such as Molina (+2) have elaborated on the model's practical application in describing the dynamic interaction between biological, psychological, and sociocultural factors. The American Board of Psychiatry and Neurology (ABPN) deems skill in biopsychosocial formulation to be important for the competent practice of psychiatry (+3). Because of its importance to psychiatry as well as to the humanistic practice of medicine, we believe that teaching the biopsychosocial formulation to medical students is integral to the role of psychiatric clerkship directors and other psychiatric faculty members.

We agree with Perry et al. (+4) that a formulation has applications beyond long-term, expressive psychotherapy and that a formulation need not be elaborate and time-consuming. However, it has not always been clear to psychiatric educators how best to teach skills in effective formulation, and most of the familiar textbooks in psychiatry give little explanation of how to actually construct a formulation. In this article we describe how a process taught to our medical students during the preclerkship problem-based learning curriculum, namely, mechanistic case diagramming (+5), is adapted to teaching the principles of biopsychosocial formulation during the third-year clerkship in psychiatry.

Third-year students at the University of Hawaii John A. Burns School of Medicine were introduced to the biopsychosocial formulation in a 1.5- to 2-hour teaching session during the first 2 to 3 weeks of their psychiatric clerkship. The session involved discussion of two videotaped interviews, conducted by students, of actual patients. After group discussion of an interview, the interviewing student was asked to present the case, during which time either the instructor (A.G.) or one of the students wrote selected facts under the columns "biological," "psychological," and "social-cultural." The instructor explained that biological factors include genetic and acquired risk factors; that psychological factors include stressors, coping abilities, life stage issues, and any other significant life events; and that social factors include social support and other issues that could affect life in the community. We feel that our view of the psychological aspect of formulation is consistent with ABPN's explanation (+3) that it should include predisposing, precipitating, and perpetuating factors and phase-of-life issues. The students were taught that social factors should also include relevant cultural issues, which, in keeping with the description of Carrillo et al. (+6), may broadly include anything in a patient's background (including religion) that could affect their health-seeking behavior or their relationships with people.

The students were then asked to apply the technique of mechanistic case diagramming (+5) to draw linkages between the biological, psychological, and social-cultural factors as they saw appropriate. Most of the students were familiar with this technique from their first two years of medical school. Briefly, the aim of the technique is to trace, in stepwise fashion, using solid arrows in a diagram, the mechanisms leading from underlying factors (including genetic and social or environmental factors) to outward manifestations of illness. +Figure 1 contains a sample diagram.

After the instructor produced the diagram, the students were asked to present verbally, as a group effort, a formulation of the case. It was emphasized that a good formulation should be logical enough to diagram as a flowchart, practical enough to guide treatment and any explanations that would be provided to the patient, the family, and other professionals, and believable to its creator. To illustrate especially the second of these, after a discussion of DSM-IV diagnosis, the students were involved in a discussion of treatment planning. Important points of intervention in the patient's pathophysiology were identified (using dotted arrows) in the biological, psychological, and social areas of the diagram. It was emphasized that a strong and well-balanced formulation is an important foundation for a treatment plan and that the plan's effectiveness would be optimal by virtue of its having been comprehensive in approach.

Through construction and discussion of the diagram depicted in +Figure 1, students might be able to appreciate the importance of addressing general medical conditions (including, in this case, the thyroid disorder) that could exacerbate psychiatric symptoms; gathering more details about life history and providing supportive therapy to address issues that might affect medication compliance and increase stress; and finding a stable living situation to prevent the problems with homelessness—all in addition to what would seem the obvious treatment of prescribing an antipsychotic medication.

Sixteen students (nine men and seven women) from two third-year clerkship blocks in 2001 who were among the first to receive this teaching module were given pre- and postsession questionnaires (+Figure 2) designed to assess their comfort level with and their beliefs about the biopsychosocial-cultural formulation. The questionnaire was not anonymous, and it was collected by the instructor (A.G.). All items in all questionnaires were completed.

For the purposes of program evaluation, paired t tests were used to determine whether there were any significant pre-post differences, and Pearson correlations were computed to ascertain associations between variables. Publication of program evaluation results was approved by the Committee on Human Studies of the University of Hawaii.

In general, all students either agreed or strongly agreed that the session was enjoyable. There were significant positive changes between pre- and postsession overall scores (t=4.74, p<0.05), in students' self-reported understanding of (t=3.28, p=0.005) and comfort with presenting and writing (t=5.33, p<0.0001) a biopsychosocial-cultural formulation. There was also a significant positive change (t=2.42, p=0.028) in students' rating of the importance of showing linkages between the biological, the psychological, and the social. No other significant changes were observed.

In the presession questionnaire, positive correlations were observed between belief that the biopsychosocial-cultural formulation is useful in the care of all patients and belief in the importance of identifying relevant ethnic and cultural factors (r=0.73, p=0.0013); belief in the importance of identifying areas of strength (r=0.83, p<0.0001); and belief in the importance of summarizing and integrating facts in a way that can guide treatment (r=0.77, p=0.0005). In the postsession questionnaire, positive correlations were observed between belief that the biopsychosocial-cultural formulation is useful in the care of all patients and belief in the importance of identifying key biological, psychological, and social factors in a balanced way (r=0.70, p=0.0026) and belief in the importance of summarizing and integrating facts in a way that can guide explanations to patients, family members, and other professionals (r=0.56, p=0.024). There were no significant correlations in either pre- or postsession questionnaires between belief in the formulation's usefulness in the care of all patients and belief in the importance of providing a detailed summary of the case; detailing the biological mechanisms underlying psychiatric illness; tracing the origin of psychiatric symptoms according to psychoanalytic theory; identifying defense mechanisms; or showing linkages between the biological, the psychological, and the social.

Limitations of this study include the small sample size and the lack of any data about whether the sessions provide any lasting benefit in improving attitudes toward and skills in biopsychosocial-cultural formulation.

We also recognize the limitations in the biopsychosocial model. This model, as commonly presented, does not necessarily place clinical problems in a historical, developmental, and biographical context. Although our diagram (+Figure 1) may include life-stage issues (for example, in this case, desire for family and job satisfaction at age 41) as part of a mechanism-based sequence, the arrows in the diagram may not explicitly provide information about the temporal relationship of events (for example, losing a child at age 19 was a more remote event than becoming homeless at age 41). Also, although our diagram may include references to predisposing, precipitating, and perpetuating factors, these factors are not explicitly labeled as such, making it necessary for the clinician to prioritize which of them (usually the perpetuating factors) may be most accessible to intervention. Finally, our attempt to structure diagrammatically the biopsychosocial-cultural approach does not incorporate all of the issues that are important for bedside care, including ethics and pragmatic decision making (+7).

Despite these limitations, we believe that mechanistic case diagramming is a potentially useful starting point in comprehensively discussing patient care. We also believe that, as a technique familiar to our problem-based learning curriculum, it may constitute a useful step toward enhancing our medical students' ability to conceptualize and address psychosocial issues during the third year and beyond (which were recognized in an internal program evaluation as potential areas for improvement in our curriculum).

If it is true, as this preliminary study suggests, that medical students are more likely to value biopsychosocial-cultural formulation if they can appreciate its usefulness in integrating multiple perspectives in a way that effectively guides treatment and explanations, then mechanistic case diagramming (with treatment interventions included) would seem to be an optimal way to convey the importance of formulation in patient care. As a relatively concrete and atheoretical technique, mechanistic case diagramming could help students appreciate the applicability of biopsychosocial-cultural formulation to situations other than long-term expressive psychotherapy and to cases in general medicine. It might also be useful in enabling educators (in psychiatry as well as in other specialties) to assess in a semiquantitative fashion the degree to which students, residents, and other trainees think holistically and address psychosocial issues—similar to the way another educational tool, concept mapping (+8), has been used in evaluating critical thinking among residents.

Overall the sessions have been enjoyable, from both the instructor's and the students' perspectives, and the students have seemed pleased to revisit a technique they had learned during preclerkship problem-based learning, which itself emphasizes the importance of the holistic approach. Because of its potential usefulness in improving and assessing skills in the comprehensive, biopsychosocial approach to patient care, we recommend that mechanistic case diagramming be further studied and possibly integrated into psychiatry curricula.