By Ellen Feldman, MD
Altru Health System, Grand Forks, ND
• A 2017 randomized controlled trial compared a 12-month collaborative care intervention for patients with comorbid obesity and depression to care as usual. The authors found that patients in the intervention arm had significantly more weight loss and improvements in measures of depression than patients in the “care as usual” arm.
• This study investigated the same population to see if the intervention was associated with improvements in health-related quality of life and psychosocial functioning, as measured by several different scales at baseline, six months, and 12 months.
• At six months (but not 12 months), intervention participants reported significantly greater improvements in measures of mental health-related quality of life, sleep-related impairments, functional disability, and obesity-specific quality of life compared to the “care as usual” arm.
SYNOPSIS: This study tracked measures of quality of life and psychosocial functioning in patients participating in a randomized clinical trial with the goal of reducing symptoms of obesity and depression. The authors found that both quality of life and psychosocial functioning significantly increased at six months compared to patients with “care as usual,” but not at 12 months.
SOURCE: Rosas LG, Azar KMJ, Lv N, et al. Effect of an intervention for obesity and depression on patient-centered outcomes: An RCT. Am J Prev Med 2020,58:496-505.
Social stigma, low self-esteem, and exacerbation of chronic medical problems are a sampling of the factors complicating treatment of either obesity or depression. Because obesity is a risk factor for depression, and depression elevates the risk of obesity, these disorders frequently appear as comorbid conditions.1,2
Recent estimates reveal both of these conditions are common, with obesity occurring in 40% of U.S. adults and depression affecting 21% at some point during a lifetime.3 Few studies have looked at rates of comorbidity among these two disorders, but there is suggestive evidence that this association is most pronounced in women. Evidence also points to poorer health-related quality of life and more significant functional impairment in patients with comorbid obesity and depression (compared to either condition alone or to neither condition).1-3
Rosas et al, looking from a different vantage point, were interested in investigating if patients with improvements in depression and comorbid obesity endorse parallel improvements in quality of life and psychosocial functioning. They reviewed data from a cohort of patients enrolled in a study of a collaborative care intervention designed to treat patients with both conditions: I-CARE (Integrated Coaching for Better Mood and Weight.) This intervention took place over 12 months, during which participants enrolled in an obesity/weight-loss group (Group Lifestyle Balance) and an additional program targeting depressive symptoms (Program to Encourage Active, Rewarding Lives). At the conclusion of 12 months, Cohen d effect scores for the intervention group were 0.28 for reduced body mass index (BMI) and 0.23 for depressive symptoms, representing a small but significant effect associated with the interventions.
The two therapies were timed to produce synergistic results with nine health coach-directed in-person sessions followed by 11 home video sessions over the first six-months, and monthly phone sessions with the health coach over the last six months.
The Short Form-8 Health Survey (SF-8), measuring both physical and mental health quality of life, and the Obesity-Related Problem Scale were used to evaluate health-related quality of life. The SF-8 asks questions such as, “Over the past four weeks, how often have you been bothered by emotional problems such as irritability, anxiety, depression?” and, “During the past four weeks, how often did your physical health limit your social activity?”4 The Obesity-Related Problem scale asks specifically about weight-related concerns, such as how bothered by obesity a respondent feels when going shopping for clothes or attending a community activity.5
Sleep-related impairment questionnaires and the three-item Sheehan Disability scale were used to measure the level of psychosocial functioning. All measurements were taken at baseline, month 6, and month 12.
Out of an initial 409 study participants, 317 individuals (78%) completed the evaluations measuring quality of life and psychosocial functional level. At six months, respondents in the intervention arm reported significantly greater improvements in all but one measure of quality of life as well as all psychosocial function measurements compared to the control arm, but none of these improvements remained statistically significant at the 12-month mark. (See Table 1.)
The first step of analysis looked at quality of life and functional improvement in the intervention vs. control arm at six and 12 months. The second step looked at a relationship between these measures and an improvement in BMI and/or reduction of depressive symptoms. At six months, improvements in the mental component of
SF- 8, the Obesity-Related Problem Scale, measures of sleep disturbance, and the Sheehan Disability Scale all were associated with improved measures of depression, but not with lower BMIs. At 12 months, all these factors were associated with both lower BMI and lower measures of depression.
In multi-variable analysis, several interesting relationships were noted. Improvements in Obesity-Related Problem Scale results and sleep disturbance were associated with decreased BMI at 12 months. Improvements in all measures of quality of life and psychosocial functioning were associated with a clinically significant reduction in measures of depression at 12 months.
Rosas et al shed new light on an investigation looking primarily at the effect of a collaborative care intervention targeted for treatment of patients with comorbid obesity and depression. Although the primary findings from the initial study are impressive (with improvement in BMI and depressive symptoms at 12 months from study entrance), this team wanted to understand whether patient-reported outcomes, such as quality of life and functional improvement, follow the trend in clinical improvement. In this work, improvements in mental health-related quality of life, obesity-related quality of life, sleep disturbances, and functional status were significantly improved at six months when compared with patients in the treatment as usual group, but not at 12 months. In part, this may have to do with the change in intervention during the study, since the second six months of treatment was more of a maintenance phase approach with monthly phone check-ins.
Interestingly, this drop-off in effect does not appear to be because of a decrease in scores in the intervention group, but rather an increase in such measures in the “care as usual” group. For example, at six months, the difference between the mean values of the intervention and control groups in the mental component of the SF-8 was significantly different at 2.9. At 12 months, this difference narrowed to a non-significant 1.7, largely because of improvement in the control arm patients, since there was little movement in scores in the intervention group.
Future studies may help clarify these relationships, but there seems to be a suggestion that active intervention post-six months may be needed for continued response.
Multi-variable analysis pointed to another interesting finding. Improvement in obesity-related quality of life and sleep disturbances were associated with weight loss, while improvement in other measures of health-related quality of life and functional impairment measures were more strongly associated with decreased depressive symptoms. The inference here is that both depression and obesity need to be targeted to reach maximum measurable improvements in patient-defined measures of quality of life and functional impairment.
The primary care provider can expect to see many patients with comorbid depression and obesity. This study, while preliminary, can serve as a reminder of the importance of evaluating patient perception of improvement while also collecting and measuring clinical data. The results from this study also imply that treatment of both obesity and depression may yield more patient-perceived benefits than focusing on either one condition alone.
- Milaneschi Y, Simmons WK, van Rossum EFC, Penninx BW. Depression and obesity: Evidence of shared biological mechanisms. Mol Psychiatry 2019;24:18-33.
- de Wit L, Luppino F, van Straten A, et al. Depression and obesity: A meta-analysis of community-based studies. Psychiatry Res 2010;178:230-235.
- Carey M, Small H, Yoong SL, et al. Prevalence of comorbid depression and obesity in general practice: A cross-sectional survey. Br J Gen Pract 2014:64:e122-e127.
- University of Florida. SF-8 health survey (4-week recall). https://education.med.ufl.edu/files/2010/10/SF81.pdf
- Wadden TA, Phelan S. Assessment of quality of life in obese individuals. Obesity Research 2002;10:50S-57S.