Enrollment was open to men and women, ages 18–72
yr, who had a body mass index (BMI) of 30–45
and suffered from MDD. They also were required to have at least one additional risk factor for CVD, which included elevations in waist circumference, blood pressure, fasting blood glucose levels, triglycerides, or reduced HDL cholesterol, as defined by the National Cholesterol Education Program (Adult Treatment Panel III) [12
]. In addition, type 2 diabetes or medications for any of these conditions were considered CVD risk factors. Exclusion criteria included a weight loss of ≥5% of initial weight in the prior 6 months, current individual or group psychotherapy, or occurrence of a cardiovascular event in the last 12 months. Participants taking selective serotonin reuptake inhibitors had to have been on a stable dose for at least 3 months prior to enrollment; individuals taking other types of antidepressants were excluded (due to their potential effects on weight). A total of 253 applicants responded to advertisements in the local media, of whom 202 were successfully contacted for a phone screening interview. (The other 51 individuals could not be reached.) Of these 202, 166 were excluded following the phone screen, the majority of whom did not meet criteria for a current depressive episode. The remaining 36 applicants were invited to attend an in-clinic screening visit at which the details of the study were explained, written informed consent was obtained, and a clinical psychologist met with participants to assess the presence of MDD using a Structured Clinical Interview for the DSM-IV (SCID) [13
]. Of these 36, 12 did not attend the visit, 5 decided they were not interested after learning more about the study, 4 did not meet the depression criteria, and 1 required treatment for another psychiatric disorder. Fourteen participants attended a second screening visit, which included collection of a fasting blood sample. One participant later determined that she would not be able to attend the group meeting when scheduled. A second participant withdrew from the program because of a family emergency, immediately before treatment began. This left 12 participants who began the trial. The study's protocol and procedures were approved by the University of Pennsylvania's Institutional Review Board.
Participants attended 16 weekly, 90-min group sessions (in groups of 6 participants) led by a clinical psychologist (LF). Half of each session was devoted to behavioral weight management skills, based on Brownell's LEARN Program for Weight Management [14
]. Participants were weighed each week, given calorie goals (i.e., 1200–1500
kcal/d) based on their initial weight, encouraged to increase exercise gradually to 180
min/wk, and taught skills such as self-monitoring and stimulus control. The other half of each session consisted of group CBT for depression, based on Bieling et al.'s group treatment for depression [15
]. Participants were introduced to the cognitive model of depression and taught to identify and modify their negative automatic thoughts and core beliefs. Participants were weighed at each group session and completed the Beck Depression Inventory-II (BDI-II) [16
] to track the course of symptoms of depression. The BDI-II is a 21-item questionnaire that assesses mood over the previous 2 weeks. Total scores range from 0 to 63, with higher values indicating greater symptoms of depression. Scores of 0–13 reflect minimal (i.e., subclinical) symptoms, whereas values of 14–19, 20–29, and ≥30 indicate mild, moderate, and severe symptoms of depression, respectively.
Participants completed outcomes assessments at baseline and week 16 at which weight, height, and other characteristics were measured. Body weight was measured on a digital scale (Detecto, model 6800A) while participants were dressed in light clothing, without shoes. Height was measured using a wall-mounted stadiometer (Veeder-Root, Elizabethtown, NC). Waist circumference and blood pressure were assessed using methods described previously [17
]. Fasting blood samples were obtained (and analyzed by Quest Diagnostics, Horsham, PA). Symptoms of depression were assessed using the HDRS by a trained, independent clinician who was masked to the aims of the study. The HDRS was the study's primary outcome for assessing changes in mood.
Changes in weight, HDRS scores, and CVD risk factors (from baseline to week 16) were assessed by within-subjects repeated-measures t-tests. Eleven of 12 participants completed the study. One participant dropped out at week 12 because of her mother's declining health; her data were carried forward from week 11 (i.e., her last in-clinic weight and BDI-II score). A second participant became pregnant at week 14. She continued attending group until the end of treatment, but no data after her pregnancy are included in the analyses. A third participant showed significant worsening in symptoms of depression at week 13, at which point treatment was intensified and therefore no longer consistent with the study protocol. She received individual treatment sessions with the study psychologist (LF), was evaluated by the study psychiatrist (RB), and was then referred to appropriate adjunctive treatment. (The participant continued to attend groups until the end of the study, but her data following treatment intensification, at week 13, were not included in data analysis.).