Of the 171 mental health consumers attending the two psychiatric rehabilitation programs, 98 were thought to be potentially eligible for the study after discussion with program staff (). Of these, 75 consumers showed interest in the study and signed informed consent to be screened formally for eligibility and for baseline data collection. Sixty-three of these completed all baseline data collection and enrolled. The suburban site participants were younger and were predominantly White (). Of the 31 African Americans, 51% were women. About half had at least a high school education, and most had never been married. Mental health diagnoses reflected a population with serious mental illness in psychiatric rehabilitation programs with over half having a schizophrenia spectrum disorder. Participants on average took at least two psychotropic medications, with most taking an atypical antipsychotic. The mean RBANS total score reflected a population with cognitive impairment, as populations with schizophrenia have been shown to have an average score of about 70 (39
). RBANS mean scores in the general population are 95. The CES-D and Symptom Checklist-90 General Symptom Index (GSI) showed high levels of mental health symptoms. A CES-D score of 16 or higher is associated with clinical depression. The SCL-90 GSI in a non-psychiatric population has a mean of 0.31 (41
). Over half of participants smoked tobacco, one third had hypertension and a fifth had diabetes mellitus.
Participant flow in weight loss intervention in psychiatric rehabilitation centers
Baseline characteristics of participants enrolled in weight loss intervention at psychiatric rehabilitation centers
Average attendance across all participants and all weight management classes was 87 percent for days that participants were present at the rehabilitation center and 70 percent overall, including days that participants did not come to the centers. Similarly, average physical activity class attendance was 74 percent for days participants were at the center and 59 percent overall. To be counted as attending physical activity class, participants had to exercise for at least 20 minutes of the 45 minute class.
Of the 63 participants, we obtained 6 month follow-up physical measurements on 52 and all measurements on 51 individuals, or 81 percent of our sample (Figure). The 11 participants without follow-up data left the rehabilitation centers before the end of the study. Five left for psychiatric hospitalizations, four left for employment, one moved to another day program and one moved to another daytime activity. One participant had a mental health relapse and left the center before we were able to complete all study follow-up. However, 58 participants completed at least eight weeks of the intervention, and we did record intervention weights for those participants.
Differences in weight were achieved after the intervention (, ). For the 52 participants completing baseline and follow-up weights, mean weight loss was 4.5 pounds. On average, participants lost 1.9% of body weight. shows the distribution in weight loss with participants’ weight change in three pound increments. Mean weight loss was 11.6 pounds or 6.1 percent of body weight for the 52 percent of participants (n=27) who lost at least three pounds. Thirty-one percent of participants (n=16) lost at least 4 percent of their body weight. Body mass index decreased by 0.8 kg/m2. We found a non-significant relationship between higher initial BMI and greater weight loss (p<0.23). In sensitivity analyses, participants attending at least 8 weeks of the intervention (n=58 had mean weight loss of 4.8 pounds (S.D. 12.1) (p<0.01) (data not shown). Analyses including all enrolled participants assuming those not completing follow-up measurements remained at their baseline weight showed mean weight loss of 3.4 pounds (S.D. 11.3), (P<0.01).
Physical health measures before and after weight loss intervention in psychiatric rehabilitation centers (N=52)
Distribution of weight change after weight loss intervention in psychiatric rehabilitation centers
Waist circumference decreased in 75 percent of participants with mean waist circumference change of 3.1 cm overall. Sixty-nine percent of participants increased the distance they walked in 6 minutes, with mean increase in 6 minute walk of 8 percent overall. Daily minutes of moderate physical activity in bouts of at least ten minutes increased by 8 minutes, or the equivalent of 56 minutes per week.
Depression scores on the CES-D improved from baseline to follow-up (). Sixty-two percent of participants had a CES-D score of 16 or higher at baseline consistent with clinical depression, and 52% had a CES-D score of 16 or higher at follow-up (p<0.06) (data not shown). Health status scores showed non-significant decreases for General Health and Physical Functioning subscales and a non-significant increase for the Social Functioning subscale. Lehman Quality of Life scores showed no change overall.
Self-reported measures before and after weight loss intervention in psychiatric rehabilitation centers (N=51)
Reported daily intake of fat and dietary cholesterol decreased from before to after the intervention while reported fruit and vegetable servings and dietary fiber increased. The General Self-Efficacy and Eating Habits Self-Efficacy scales showed no change. The Sticking to Exercise scale of Exercise Self-Efficacy showed a small negative change. The modified Binge Eating Scale showed no significant change in mean score, although 24.5% at baseline had at least moderate binge eating and only 16.3% at follow-up had moderate binge eating (p<0.007). Total and LDL cholesterol, glucose and insulin levels and HOMA-IR showed non-significant decreases, while triglycerides and diastolic blood pressure showed non-significant small increases.
Possible Weight Loss Correlates
We did not find differences in weight change by race, gender, psychiatric diagnosis or by cognitive level (data not shown). In addition, we did not detect differences in weight change between participants receiving different types of psychotropic medications, including atypical antipsychotics and olanzapine. Although depression level improved after the intervention, change in weight was not related to change in depression levels. We also did not find relationships between self-efficacy constructs, attendance or reported dietary intake and weight change. In addition, eating habit self-efficacy was not related to reported diet or dietary change. Exercise self-efficacy was not associated with exercise attendance.
This six month pilot study documented the feasibility and preliminary efficacy of a behavioral weight loss intervention in adults with serious mental illness in a psychiatric rehabilitation setting. Participants decreased their weight and their waist circumference, and they attained modest increases in physical fitness as measured by six-minute walk and in moderate intensity physical activity. Depression scores decreased as did the percentage of participants reporting at least moderate binge eating behavior after the intervention. The degree of weight loss attained should be associated with decreased blood pressure and cardiovascular disease risk (42
Rehabilitation center attendees showed interest in the weight loss intervention. Almost two-thirds of all potentially eligible consumers (and over one third of all consumers at the programs) were recruited, completed all screening and baseline measures and enrolled in the study. The weight loss intervention was well accepted by subjects as evidenced by their participation in weight management and exercise classes, and retention was high.
We saw some objective evidence that participants made lifestyle changes during the study. The distance traveled during the 6 minute walk test, a proxy for physical fitness, and physical activity measured by accelerometry both increased. These are consistent with physical activity class participation. Participants also reported less fat and dietary cholesterol intake and increased fruit, vegetable and dietary fiber daily.
This study adds to the growing body of evidence from small studies showing that persons with serious mental illness can benefit from short-term behavioral weight loss interventions (3
). Most studies of weight loss interventions for those with chronic mental illness emphasize dietary change; fewer incorporate group physical activity, and of those, most consist of only weekly physical activity (13
). A recent study from Israel in long-term psychiatric inpatients with schizophrenia incorporated exercise five times per week and showed a 1.8 (SD 2.3) unit decrease in BMI at 3 months for the intervention compared to a 0.34 (SD 4.3) decrease in the comparison group (44
). Studies focusing on nutritional interventions showed differences in weight in intervention groups compared to controls (loss or reduced gain) between 2 and 11 pounds. Littrell et. al. studied persons with schizophrenia or schizoaffective disorder taking olanzapine and showed 9 pounds of weight gain in controls and no weight loss in the active group after a 4 month educational intervention (21
). Brar, et. al. showed a 1kg decrease in weight compared to control after a 14 week behavioral intervention in patients with schizophrenia or schizoaffective disorder switched from olanzapine to risperidone (19
). In a 16 week behavioral intervention in 17 patients with schizophrenia taking only one atypical antipsychotic, Weber et.al. reported a 5.4 pound weight loss in the intervention group compared to 1.3 pounds loss in controls (23
). A study by McKibbin of a 6-month behavioral weight loss intervention for persons with schizophrenia and diabetes showed a 5 pound weight loss in the intervention group and a 6 pound weight gain in controls (18
Studies incorporating some physical activity component in the intervention, mainly once to twice weekly walking groups, with or without a control group, also showed a similar range of weight loss. Richardson et.al. performed a pre/post study including persons with a range of serious mental illnesses in an 18 week intervention (16
). They reported only one-third of participants completed the study; of these, mean weight loss was 5.3 pounds. Ball et. al. studied persons taking a specific range of olanzapine dose and showed no overall difference in weight loss between intervention and control groups with 69% follow-up, although men in the intervention group did lose weight (13
). Menza et.al. studied persons with schizophrenia or schizoaffective disorder taking atypical antipsychotics and showed a 6.6 pound weight loss in the intervention group and 7.0 pound gain in the control group with 65% follow-up at 12 months (15
Most of the current literature highlighted above focuses on particular diagnoses and/or medications, reports results only for intervention completers or does not include a strong physical activity intervention component. Moreover, many do not follow guidelines for reporting randomized or non-randomized evaluations of behavioral interventions (24
Our study is one of the first to integrate weight management and physical activity classes into a psychiatric rehabilitation environment. The study population was ethnically diverse with a high burden of mental health symptoms and cognitive deficits. Unlike most previous weight loss studies for persons with serious mental illness, we included all interested and eligible rehabilitation center attendees, and did not limit to participants with only on one mental health diagnosis or class of antipsychotic medication.
In this lifestyle intervention study without a control group, weight changed the expected amount from before to after the intervention. Because adults typically gain weight over time, we may have expected net weight loss to be even greater in a controlled trial (18
). Average weight gain in populations with serious mental illness has not been reported but is likely higher than the general population. This information would be helpful in interpreting intervention results. We were also limited by sample size and by our lack of control group in detecting changes in instrument measures that may be related to weight loss. Although participants reported some dietary changes, we did not find these to be related to weight change. However, the dietary screeners capture less information about high-calorie beverages, which appeared to be one large calorie source that our participants decreased. We also did not find a statistical relationship between exercise participation and weight loss, although it is possible that the regular, moderate intensity physical activity in a previously sedentary group contributed to the intervention’s success. On-site physical activity classes may be particularly beneficial for a chronically mentally ill population as only participation is required, whereas dietary changes which rely on individual behavior may be more challenging.
Other measures that we thought might be either on the pathway to weight loss, such as self-efficacy, or associated with weight loss, like quality of life or health status, did not change after the intervention. Self-efficacy can decrease when individuals realize how hard it is to make sustained change in behaviors. Although most of these measures have been used previously in persons with serious mental illness, it is possible that our participants’ cognitive impairments may have limited the utility of some measures. At the same time, while not captured on standard instruments, we observed that participants often helped each other motivate to join in the exercise classes and believe that this type of social support made important contributions to intervention success.
Strengths of this pilot study include engaging an understudied, vulnerable population in a behavioral weight loss intervention. We obtained high rates of study enrollment, intervention participation and follow-up data collection. The small sample size and pre-post test design were appropriate for a pilot study, but the results need confirmation in larger, controlled studies. In addition, we had limited power for subgroup analyses.
This study has limitations. In addition to the lack of a comparison group, we did not specifically assess how well the participants understood the intervention or components. We also did not measure nutrition, weight management or physical activity knowledge. Moreover, while the participant selection process for the intervention would likely generalize to other psychiatric rehabilitation settings where staff know consumers well and work with them closely, it may not be best for mental health settings where this is not the case. In addition, we were not able to measure the effect of educating the kitchen staff to change the food environment on individual patient outcomes.
While these study results are relevant particularly for persons with chronic mental illness, the success of this pilot weight loss intervention has broader implications for populations with obesity in institutional settings. By appropriately tailoring the intervention and holding sessions at a time and familiar place where participants already attend regularly, we minimized barriers to group participation in a population with transportation, health and social barriers that make them generally poor candidates for traditional behavioral weight loss programs. Including exercise classes provided important opportunities for participants unlikely to reach moderate physical activity goals on their own. Day programs for elderly or disabled adults, prisons, schools or nursing homes may all be settings where similar programs to decrease obesity could be tested and implemented.
In summary, we tailored a behavioral weight loss intervention to the needs of persons with serious mental illness in psychiatric rehabilitation programs. Over the course of six-months, this intervention appeared feasible and effective in participants with a broad range of psychiatric and cognitive impairments. Randomized controlled studies of comprehensive weight loss interventions incorporating weight management and physical activity for persons with serious mental illness are needed to provide evidence of successful interventions that can be disseminated to ameliorate the health burden of obesity in this vulnerable population.