Objective The primary aim of this study was to determine whether enrolment in collaborative care management (CCM) for treatment of major depression would have a significant impact on 6-month changes in weight compared with patients treated by their primary care provider with usual care. The secondary aim was to determine whether clinical remission would also affect 6-month weight changes. Design A retrospective chart review study included 1550 patients who had been diagnosed with major depression or dysthymia and who had a Patient Health Questionnaire (PHQ-9) score of ≥ 10 with follow-up data (PHQ-9 score and weight) at 6 months. Subjects The study sample consisted of adult patients (aged ≥ 18 years) from primary care practices, representing all body mass index (BMI) categories. The exclusion criteria were a diagnosis of bipolar disorder, recent obstetric delivery or recent gastric bypass procedure. Measurements Weight was measured at index and 6 months, with BMI calculated from electronic medical record data. Patient assessment data (including PHQ-9 score and clinical diagnosis) and demographic variables (age, gender, marital status and clinical location) were also collected. Results With regression modelling, neither enrolment in CCM (P = 0.306) nor clinical remission (P = 0.828) was associated with a significant weight gain. Conclusion After 6 months, enrolment in CCM had no significant impact on weight gain or weight loss among patients treated for depression, nor was improvement to clinical remission a factor in the patient's weight after 6 months. Incorporating a weight loss management intervention within the model may be warranted if concomitant weight reduction is desired.
Keywords: collaborative care management; depression; obesity; primary care.