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. Author manuscript; available in PMC: 2014 Feb 1.
Published in final edited form as: J Psychosom Res. 2013 Jan 3;74(2):161–169. doi: 10.1016/j.jpsychores.2012.11.010

Associations between physical activity and mental health among bariatric surgical candidates

Wendy C King 1, Melissa A Kalarchian 2, Kristine J Steffen 3, Bruce M Wolfe 4, Katherine A Elder 5, James E Mitchell 6
PMCID: PMC3556899  NIHMSID: NIHMS423605  PMID: 23332532

Abstract

Objective

This study aimed to examine associations between physical activity (PA) and mental health among adults undergoing bariatric surgery.

Methods

Cross sectional analysis was conducted on pre-operative data of 850 adults with ≥ class 2 obesity. PA was measured with a step activity monitor; mean daily steps, active minutes, and high-cadence minutes (proxy for moderate-vigorous intensity PA) were determined. Mental health functioning, depressive symptoms and treatment for depression or anxiety were measured with the Medical Outcomes Study 36-item Short Form, Beck Depression Inventory, and a study-specific questionnaire, respectively. Logistic regression analyses tested associations between PA and mental health indicators, controlling for potential confounders. Receiver operative characteristic analysis determined PA thresholds that best differentiated odds of each mental health indicator.

Results

Each PA parameter was significantly (P<.05) associated with a decreased odds of depressive symptoms and/or treatment for depression or anxiety, but not with impaired mental health functioning. After controlling for sociodemographics and physical health, only associations with treatment for depression and anxiety remained statistically significant. PA thresholds that best differentiated those who had vs. had not recently received treatment for depression or anxiety were <191 active minutes/day, <4750 steps/day, and <8 high-cadence minutes/day. Utilizing high-cadence minutes, compared to active minutes or steps, yielded the highest classification accuracy.

Conclusion

Adults undergoing bariatric surgery who meet relatively low thresholds of PA (e.g., ≥ 8 high-cadence minutes/day, representative of approximately one hour/week of moderate-vigorous intensity PA) are less likely to have recently received treatment for depression or anxiety compared to less active counterparts.

Keywords: anxiety, bariatric surgery, depressive symptoms, exercise, Roux-en-Y gastric bypass, severe obesity

INTRODUCTION

Mental disorders, such as depression and anxiety, have become the leading cause of disability in the developing world (1). National survey results indicate that adults with obesity, and in particular severe obesity (body mass index [BMI] ≥ 40 kg/m2), are disproportionately affected (2-8). This is especially true for women (2;7;9;10), who appear to suffer more psychological consequences from obesity, such as body image dissatisfaction, stigmatization, and discrimination (11-14).

Studies of clinical populations suggest that a sizeable portion of adults seeking bariatric surgery, the majority of whom are severely obese females, have current depression or anxiety disorders. For example, Kalarchian and colleagues, who assessed Axis I disorders (i.e., Mood, Anxiety, Eating and Substance disorders) with structured interviews independent of the surgery approval process in consecutive bariatric surgery cases (n=288), reported that 10.4% of preoperative patients had current major depressive disorder (42.0% lifetime), while almost a quarter (24.0%) had a current anxiety disorder (37.5% lifetime) (15). In comparison, using similar assessment methods Muhlhans and colleagues (n=146) reported a higher rate of major depressive disorder (25.3%; 50.7% lifetime), but a lower rate of anxiety disorders (15.1%; 21.5% lifetime) (16). These estimates straddle the prevalence of current major depressive disorder and anxiety disorders (13.3% and 19.6%, respectively) reported in a national sample of adults with severe obesity, and are almost two-fold higher than in normal weight adults (7.2% and 10.2%, respectively) (6).

There is evidence to suggest that depressive symptoms and the prevalence of major depressive disorder decrease after bariatric surgery (10;17;18). However, the same has not been consistently shown for symptoms of anxiety and anxiety disorders (17-19). In addition, preoperative depression and anxiety increase risk of their counterpart postoperative conditions (18;20), and have been shown to have a negative impact on long-term surgically induced weight loss (18;21;22). These findings underscore the importance of providing appropriate mental health care to pre- and post-operative patients with depression and anxiety disorders.

Typical management of depression and anxiety by clinical professionals involves counseling and/or antidepressant or anti-anxiety medication (23). In the past decade research has focused on whether physical activity (PA) may also help in the prevention or treatment of depression and anxiety. Recent meta-analyses and systematic reviews have concluded that exercise 1) is effective as a standalone treatment in reducing depressive symptoms among adults without clinical depression (24); 2) reduces depressive symptoms among patients with chronic illness (25); 3) compares favorably to antidepressant medications as a first-line treatment for mild to moderate depression (26); 4) alleviates depressive symptoms among adults with major depression (27), with comparable results to psychotherapy or antidepressant medications (28-30); and 5) improves depressive symptoms when used as an adjunct to medication (26). However, only a handful of studies have investigated whether exercise improves depressive symptoms in obese adults, with mixed results (31-33), and to our knowledge there are no published studies testing PA interventions to treat depression or anxiety in adults with severe obesity.

In recent years, a few studies have examined associations between PA and mental health in severely obese adults, and more specifically in bariatric surgery candidates. In 2006, Bond et al., administered the International Physical Activity Questionnaire-Short form (IPAQ-S) and the Medical Outcomes Study 36-item Short-Form (SF-36) to adults seeking Roux-en-Y gastric bypass (RYGB). No difference in mental health functioning, as assessed with the Mental Component Summary (MCS) score, or any of the SF-36 mental domain scores, was found between adults who reported sufficient PA (defined as reporting at least 30 minutes of moderate intensity PA for at least 5 days in the past week; n=31) vs. those who reported less PA (n=58) (32). In 2009, Bond et al., found some support for a relationship between postoperative PA participation, assessed with the IPAQ-S, and change in mental health functioning following RYGB. Specifically, improvement in the MCS score from pre- to 1 year postoperative was significantly higher among those who were active (defined in this study as reporting at least 200 minutes of moderate intensity PA in the past week) pre- and post-operative (n=68) or only postoperative (n=83), compared to those who reported less PA pre- and postoperative (n=39) (33). However, there was not a significant correlation between change in self-reported PA and change in SF-36 MCS score from pre- to 1 year postoperative, making interpretation of results difficult. More compelling evidence for a link between PA and mental health among bariatric patients was reported by Rosenberger et al. in 2011. Based on the 4-item Godin Leisure Time Questionnaire, PA frequency and intensity 1 year post-RYGB were independently associated with better mental health functioning, as measured by the SF-36 MCS score, and fewer depressive symptoms, as measured with the Beck Depression Inventory (BDI), at that same time point, after controlling for sex, age, ethnicity, preoperative body mass index, and preoperative SF-36 and BDI scores (n=131) (34). Similarly, Larson et al, found a significant association between a composite physical exercise score from the Sport Index of the Baecke Questionnaire, and mental health functioning (SF-36 MCS score) in 157 adults who were 1 to 6 years post-laparoscopic adjustable gastric banding (35). While these studies provide some evidence of a link between PA and mental health among bariatric surgery patients, they all rely on self-reported PA and do little to inform preoperative PA recommendations.

To address shortcomings in the literature, this study sought to determine whether objectively-measured PA was associated with mental health in a large (n=850) cohort of adults undergoing bariatric surgery. Specifically, we examined associations between ambulatory PA and three mental health indicators: impaired mental health functioning, depressive symptoms, and treatment for depression and/or anxiety. We aimed to determine whether associations 1) differed by various parameters of PA (i.e., active minutes, an inverse to sedentary time, high-cadence minutes, a proxy for minutes of moderate-vigorous intensity PA, and steps, a measure of total ambulatory PA), and 2) were independent of the effects of sociodemographics and physical illness and disability. In addition, we attempted to determine thresholds of PA that best differentiated mental health status.

METHODS

Sample

The Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) is an observational study designed to assess the risks and benefits of bariatric surgery (38). Between February, 2006 and February, 2009 patients at least 18 years old seeking bariatric surgery by participating surgeons at ten hospitals throughout the United States were asked to participate if they had not had previous weight loss surgery. By study enrollment closure (April 2009), 2458 participants attended a research visit prior to undergoing a bariatric surgical procedure as part of clinical care. The current analysis is limited to participants with preoperative PA and mental health data (n=850) (Figure).

Figure.

Figure

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Recruitment and Data Collection in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) Study.

The study was carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. All participating centers had institutional review board approval and all participants provided informed consent. The study, #NCT00465829, is registered at www.clinicaltrials.gov.

Measures

Measures were collected independently of the surgery approval process and clinical care. Participants were informed that their responses were confidential, although the informed consent document specified that investigators could take steps to prevent serious harm (e.g., if suicidal ideation were reported).

Physical activity

Preoperative PA was assessed in one half (n=1228; 50.0%) of LABS-2 participants with the StepWatch™ 3 Activity Monitor (OrthoCare Innovations, Washington, D.C.) (Figure). The StepWatch is a small (75×50×20 mm), lightweight (38g) microprocessor-controlled biaxial activity monitor, worn above the ankle that combines acceleration, position, and timing information to count strides per time interval. It is accurate in lean and obese individuals at “slow” (i.e. 1 mph) and “purposeful walking” (i.e. 2 and 3 mph) paces and with a variety of gait styles, with accuracy typically exceeding 98% (39). Trained research staff programmed the StepWatch to double count strides (i.e. to equal steps) in 1 minute intervals with sensitivity settings appropriate to participant’s height, cadence, and gait speed. Settings were verified at slow, normal and fast walking speeds. Participants were asked to wear the StepWatch for the seven consecutive days following their research visit. Raw StepWatch data from the manufacturer software were exported to a SAS version 9.2 database (SAS Institute Inc, Cary, NC). Step counts at the minute level were screened for signs of monitor malfunction. Non-wear periods were identified by intervals of at least 120 minutes with no activity (40). Daily wear time was calculated as 24 hours minus the duration of non-wear periods. Days with at least 10 hours of monitor wear time were considered valid. Algorithms developed in SAS used steps per minute data from valid days of participants with at least three such days (n=927; 75.6%) to calculate average daily values for the following PA parameters: steps; minutes of activity (number of 1-minute intervals with step count greater than 0); and high cadence minutes (number of 1-minute intervals with step count greater than 80).

Impaired mental health functioning

Self-reported functional health and well-being over the past four weeks was assessed with the Medical Outcomes Study 36-item Short-Form (SF-36), a widely used instrument with well-established validity and reliability (41). Items are used to generate a score in four physical health (physical functioning, role limitations due to physical problems, bodily pain, and general health) and four mental health (vitality, social functioning, role limitations due to emotional problems, and mental health) scales, as well as two summary scores: the Physical Component Summary (PCS) and the Mental Component Summary (MCS). Scores range from 0 to 100, with lower scores indicating greater impairments. Scores were standardized to a population normal distribution (mean=50, standard deviation=10) (42). Individuals whose MCS score was below 40 (i.e. at least one standard deviation below the national mean) were classified as having impaired mental health functioning (42).

Depressive symptoms

Symptoms of depression over the past week was assessed using the Beck Depression Inventory (BDI), version 1 (43), which has well-established validity and reliability (44) and is one of the most widely used instruments in psychological evaluations of bariatric surgery candidates (45). The 21 item test is scored by assigning a value of 0 (absence of the symptom) to 3 (severe symptoms) to each response resulting in a total score ranging from 0 to 63; higher scores indicate greater depressive symptomatology. Because many patients are advised to lose weight in preparation for bariatric surgery, no points were assigned to the one BDI item that assesses weight loss (I have lost more than 5 pounds) for participants who endorsed the statement, “I am purposefully trying to lose weight by eating less,” which was added as a yes/no item to the LABS-2 BDI form (38). The following cut-offs for the BDI were applied to the total score: 0-9, 10-18, 19-29 and 30-63, reflecting minimal (sub-clinical), mild, moderate and severe symptomatology, respectively. Due to the distribution of responses categories were collapsed [mild-severe symptoms (BDI score ≥10) and moderate-severe symptoms (BDI score ≥19)] for analysis.

Treatment for depression and anxiety

Participants self-reported history of treatment for psychiatric or emotional problems including reason(s) for treatment, hospital admissions, counseling with a mental health professional, and psychotropic medication use with the LABS-2 Psychiatric and Emotional Test Survey (38). Recent treatment for depression or anxiety was defined as counseling or hospitalization in the past 12 months for depression or anxiety, or current antidepressant medication (e.g., Fluoxetine, Paroxetine) or benzodiazapine anxiolytics (e.g., Lorazepam, Diazepam) use for “psychiatric or emotional problems.”

Covariates

Selection of potential confounders and mediators was based on the published literature (5;46;47). Waist circumference, height, and weight measurements were made by certified research staff. BMI was calculated as weight (kg) divided by height squared (m2). Demographics, smoking status, use of recreational drugs and walking aid use were assessed with LABS-2 questionnaires (38). The Alcohol Use Disorders Identification Test (48) was used to assess symptoms of alcohol use disorder experienced over the past year (49). Chronic medical conditions (hypertension, history of stroke, ischemic heart disease, congestive heart failure, hyperlipidemia, diabetes, sleep apnea, pulmonary hypertension, asthma, abnormal renal function, venous edema with ulcerations and urinary incontinence) were determined using a combination of clinical assessment, self-report, and medical chart review by trained researchers. The number of chronic medical conditions was summed (range: 0-12) to provide a rough estimate of disease burden, as disease severity was not taken into account and all diseases were weighted equally. Three of the four SF-36 physical scales were also utilized as measures of physical health: 1) physical functioning, which assesses ability to complete activities of daily living; 2) role limitations due to physical problems, which measures physical limitations in fulfilling social and occupational roles; and 3) bodily pain, which measures both the frequency and severity of physical pain. The fourth physical scale, general health perception, was not included because it measures both physical and mental health (50).

Statistical analysis

Characteristics of LABS-2 participants in the current analysis versus those who were excluded due to missing PA or mental health data (Figure) were compared with Pearson’s chi-square test for categorical variables and the Wilcoxon rank-sum test for continuous variables. Pearson’s chi-square test was also used to test for associations between mental health indicators. Logistic regression analyses were used to assess associations between PA parameters (entered as continuous variables) and 1) impaired mental health functioning, 2a) mild-severe depressive symptoms, 2b) moderate-severe depressive symptoms, and 3) recent treatment for depression or anxiety. For ease of interpretation, continuous PA parameters were entered with the following units: 100 active minutes/day, 1000 steps/day and 10 high-cadence minutes/day.

Next, we constructed multivariable logistic regression models adjusting for sex as well as any of the following factors that reached statistical significance (defined as P<.05): age, race, ethnicity, marital status, education, employment status, household income, smoking status, alcohol use disorder symptoms, recreational drug use, BMI, waist circumference, number of chronic medical conditions, walking aid use, and physical functioning, role limitations due to physical problems, and bodily pain scores. Use of antidepressant or anxiolytic medication was also considered as a covariate in models of impaired mental health functioning and depressive symptoms. Initial analyses with race, education, income, and employment led to collapsing categories when relationships did not differ significantly between all categories. Continuous measures were centered. All potential interactions between variables in the final models were tested.

Receiver operative characteristic (ROC) analysis was used to determine the threshold of each PA parameter that best differentiated odds of each mental health indicator. Analyses were repeated with categorical PA measures based on these thresholds. The C-statistic was used to compare the classification accuracy of competing models. Associations from logistic regression models are reported using odds ratios with 95% confidence intervals. Analyses were conducted using SAS, version 9.2.

RESULTS

Description of the sample

Characteristics of the analysis sample (n=850) are shown in table 1. LABS-2 participants who were excluded from analysis (n=1608) were similar (p>.05) for the most part. However, a greater proportion of the analysis sample was younger (median age 45 vs. 46 years; p=.01), Caucasian (88.6% vs. 84.4%; p<.01), employed full-time (74.1% vs. 65.6%; p<.0001), and had a household income ≥ $25,000 (86.0% vs. 79.2%; p<.0001), while fewer had impaired mental health functioning (19.7% vs. 30.3%; p<.0001). In addition, fewer used a walking aid (12.0% vs. 16.6%; p<.01), reflecting the exclusion criteria for PA assessment (i.e. exclusive wheel chair use and medical condition other than obesity that limits walking, such as multiple sclerosis).

Table I.

Characteristics of Study Participants (n=850).

n=850a
Sex
 Male 177 (20.8)
 Female 673 (79.2)
Age, years, median (IQR) [range] 45 (36-53) [18-78 ]
Race
 White 749 (88.6)
 Black 66 (7.8)
 Other 30 (3.6)
Ethnicity
 Hispanic 49 (5.8)
 Non-Hispanic 801 (94.2)
Marital status
 Married/regular partnership 546 (64.5)
 Single 142 (16.8)
 Divorced/Separated 145 (17.1)
 Widowed 14 (1.7)
Education
 ≤ High school 177 (20.9)
 Some college 341 (40.3)
 ≥ College degree 329 (38.8)
Employment status
 Employed 628 (74.1)
 Unemployed 35 (4.1)
 Homemaker 43 (5.1)
 Retired 37 (4.4)
 Disabled 96 (11.3)
 Other 9 (1.1)
Household income
 < $25,000 116 (14.0)
 $25,000-$49,000 224 (27.0)
 $50,000-$74,999 211 (25.5)
 $75,000-$99,999 140 (16.9)
 ≥ $100,000 138 (16.7)
Smoking
 Never 481 (56.7)
 Former 255 (30.0)
 Current/recent 113 (13.3)
Alcohol use disorder symptoms 60(7.1)
Recreational drug use 33(3.9)
Body mass index,b median (IQR) [range] 45.8 (42.0-51.3) [33.7-81.0]
Waist circumference, cm, median (IQR) [range] 130.0 (120.2-141.1) [ 94.9-194.4]
Number of chronic medical conditionsc, %
 0 41 (5.1)
 1 110 (13.6)
 2 160 (19.8)
 3 145 (18.0)
 4 108 (13.4)
 5 113 (14.0)
 ≥6 130 (16.1)
Walking aid use 100 (12.0)
Select SF-36 physical scores, median (IQR) [range]
 Bodily pain 39.6 (35.4-48.5) [18.0-60.4]
 Physical functioning 37.1 (28.4-45.8) [13.1-56.8]
 Role-physical 40.8 (33.4-55.6) [26.0-55.6]
Physical activity, median (IQR) [range]
 Steps/day 7321.0 (5563.0-9460.0) [1443.5-21618.0]
 Active minutes/day 304.5 (245.4-374.7) [73.8-591.2]
 High-cadence minutes/day 9.3 (4.7-16.3) [0.0-132.0]
SF-36 Mental Composite Summary score, median (IQR) [range] 51.6 (42.6-57.2) [17.7-71.0]
 Poor Mental Health Functioning (≤40) 167 (19.7)
Beck Depression Inventory score, median (IQR) [range] 6 (3-11) [0-37]
Depressive symptoms
 Minimal (0-9) 580 (68.2)
 Mild (10-18) 207 (24.4)
 Moderate (19-29) 56 (6.6)
 Severe (30-63) 7 (0.9)
Recent treatment for depression or anxietyd 333 (39.2)
  Medication 302 (91.2)
  Counseling 154 (46.5)
  Hospitalization 8 (2.4)
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Abbreviations: BMI, body mass index, cm, centimeters, SF-36, Medical Outcomes Study 36-item Short Form.

a

Values are expressed as No. (%) unless otherwise indicated. The number of participants across categories may not sum to the total number of participants because of missing data.

b

Calculated as weight in kilograms divided by height in meters squared.

c

The following chronic medical conditions were considered: hypertension, history of stroke, ischemic heart disease, congestive heart failure, hyperlipidemia, diabetes, sleep apnea, pulmonary hypertension, asthma, abnormal renal function, venous edema with ulcerations and urinary incontinence.

d

Counseling or hospitalization in past year or current use of antidepressant or anxiolytic medication for “psychiatric or emotional problems.”

Associations between mental health indicators

A higher percentage of those reporting recent treatment for depression or anxiety reported impaired mental health functioning (31.1% vs. 11.6%; p<.0001), mild-severe depressive symptoms (46.0% vs. 22.6%; p<.0001) and moderate-severe depressive symptoms (14.5% vs. 3.4%; p<.0001), than those who did not report having received recent treatment.

Physical activity and mental health indicators

None of the PA parameters were related to impaired mental health functioning (p>.05 for all analyses; data not shown). In unadjusted analyses, a lower PA level, as measured by steps, active minutes, or high-cadence minutes, was significantly associated with an increased likelihood of having mild-severe depressive symptoms (Table 2), but not moderate-severe symptoms, which were less common and thus required a large effect size in order for an association to be detected (p>.05 for all analyses; data not shown). After controlling for bodily pain and physical role limitations (which were significantly associated with less PA and greater likelihood of depressive symptoms; data not shown), PA parameters were no longer significantly associated with depressive symptoms. Income and antidepressant or anxiolytic medication use also had lesser confounding effects, while sex and age, which also entered the multivariable models (Table 2) did not appear to influence the relationship between PA and depressive symptoms.

Table 2.

Odds Ratios of Mental Health Indicators for Each Unit Decrease in Physical Activity Parameters.

Unadjusted odds
ratio (95% CI)		 C Statistic Adjusted odds
ratio (95% CI)		 C Statistic
Depressive Symptoms a
 Mean active minutes (100/day) 1.18 (1.01, 1.38) .55 1.06 (0.89-1.27)c .77
 Mean steps (1000/day) 1.08 (1.02, 1.13) .56 1.03 (0.97-1.09)c .77
 Mean high cadence minutes (10/day) 1.22 (1.05, 1.41) .58 1.04 (0.89-1.22)c .77
Treatmentb for depression or anxiety
 Mean active minutes (100/day) 1.13 (0.98, 1.31) .53 1.08 (0.91-1.29)d .71
 Mean steps (1000/day) 1.06 (1.01, 1.11) .55 1.06 (1.00-1.12)d .72
 Mean high cadence minutes (10/day) 1.31 (1.14, 1.51) .59 .72
  Physical role limitations SF-36 score=40 - 1.30 (1.10-1.55)d,e
  Physical role limitations SF-36 score=50 - 1.56 (1.25-1.96)d,e
  Physical role limitations SF-36 score=60 - 1.87 (1.34-2.62)d,e
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Abbreviations: CI, confidence interval, SF-36, Medical Outcomes Study 36-item Short Form.

a

Beck Depression Inventory score ≥10.

b

Counseling or hospitalization in past year or current use of antidepressant or anxiolytic medication for “psychiatric or emotional problems.”

c

Adjusted for sex, age, income, antidepressant or anxiolytic medication use, and bodily pain and physical role limitations problems SF-36 scores.

d

Adjusted for sex, race, education, employment status, recreational drug use, waist circumference, and bodily pain and physical role limitations SF-36 scores.

e

There was a significant interaction between high cadence minutes and the physical role limitations SF-36 score, such that the magnitude of the association between high cadence minutes and treatment for depression and anxiety was greater among those with fewer limitations.

Fewer daily steps and high-cadence minutes, but not active minutes, were significantly associated with an increased odds of recent treatment for depression or anxiety in unadjusted analyses. However, after controlling for significant confounders and mediators (i.e., employment status, education, bodily pain and physical role limitations) only high-cadence minutes remained statistically significant (Table 2). There was a significant interaction between high-cadence minutes and physical role limitations such that the association between high-cadence minutes and recent treatment for depression or anxiety was stronger for those with fewer limitations. For example, for those whose physical role limitations score was 60 (indicating few limitations), every 10 high-cadence minutes per day decrease in PA was associated with 87% higher odds of recent treatment for depression or anxiety, whereas the same decrease in PA was associated with 30% higher odds of recent treatment for those whose physical role limitations score was 40 (indicating impairment).

Using ROC analysis the following cut points in PA parameters were determined to best differentiate those who did vs. did not report mild-severe depressive symptoms: <287 active minutes, <5740 steps, and <5 high cadence minutes per day; PA cut points for differentiating between those who did vs. did not receive recent treatment for depression or anxiety were: <191 active minutes, <4750 steps, and <8 high cadence minutes per day. Participants who did not meet each threshold of PA (10-45% of participants depending on the measure) had significantly increased odds of depressive symptoms and recent treatment for depression or anxiety (Table 3). After adjusting for potential confounders and mediators, categorical PA measures were no longer significantly associated with depressive symptoms. However, all three categorical PA measures were significantly independently related to recent treatment for depression and anxiety, (e.g., compared to being active at least 191 minutes/day, not being at least this active was associated with a 125% higher odds of recent treatment for depression and anxiety) (Table 3). Classification accuracy of models predicting treatment for depression and anxiety was highest when high-cadence minutes was entered as a continuous measure (Table 2), followed by high-cadence minutes entered as a dichotomous variable (Table 3).

Table 3.

Associations Between Not Meeting Physical Activity Thresholds and Mental Health Indicators Presented with Logistic Regression Derived Odds Ratios (ORs) and 95% Confidence Intervals.

Proportion
not meeting
PA threshold		 Unadjusted odds
ratio (95% CI)		 C statistic Adjusted odds
ratio (95% CI)		 C statistic
Depressive Symptoms a
 Mean active minutes (<287/day) 43.3% 1.52 (1.14-2.04) .55 1.27 (0.90-1.78)c .77
 Mean steps (<5740/day) 27.4% 1.65 (1.20-2.27) .55 1.19 (0.82-1.73)d .77
 Mean high cadence minutes (<4.7/day) 24.7% 1.87 (1.21-2.26) .56 1.15 (0.78-1.70)d .77
Treatmentb for depression or anxiety
 Mean active minutes ( <191/day) 9.8% 2.32 (1.47-3.67) .54 2.25 (1.31-3.86)e .72
 Mean steps (<4750/day) 16.8% 1.79 (1.25-2.57) .54 1.81 (1.17-2.82)e .72
 Mean high cadence minutes (<8.1/day) 44.7% 1.94 (1.47-2.57) .58 1.92 (1.38-2.67)e .73
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Abbreviations: CI, confidence interval, PA, physical activity, SF-36, Medical Outcomes Study 36-item Short Form.

a

Beck Depression Inventory score ≥10.

b

Counseling or hospitalization in past year or current use of antidepressant or anxiolytic medication for “psychiatric or emotional problems.”

c

Adjusted for sex, income, antidepressant medication or anxiolytic use, and bodily pain and physical role limitations SF-36 scores.

d

Adjusted for sex, age, income, antidepressant medication or anxiolytic use, and bodily pain and physical role limitations SF-36 scores, and an interaction between age and the physical role limitations SF-36 score.

e

Adjusted for sex, race, education, employment status, recreational drug use, waist circumference, and bodily pain and physical role limitations SF-36 scores.

DISCUSSION

Key findings

The results of this LABS-2 study confirm and extend previous research by demonstrating an inverse association between PA and indicators of poor mental health, in a large cohort of adults with class 2 and class 3 (i.e., severe) obesity prior to undergoing bariatric surgery. Specifically, individuals who were active for more minutes each day, who accumulated more daily steps, and who achieved more high-cadence minutes, had a lower odds of depressive symptoms and a lower odds of recent treatment for depression or anxiety. Our study also confirms that a sizeable portion of patients undergoing bariatric surgery are affected by mental health issues. Approximately two in five participants (39.2%) reported recent treatment for depression or anxiety, the majority (91.2%) of whom reported current antidepressant medication or anxiolytic use for psychiatric or emotional problems. Compared to those not reporting treatment for depressive or anxiety, a greater percentage of those reporting treatment reported impaired mental health functioning and depressive symptoms, indicating that they may benefit from alternative or supplemental treatment modalities, such as PA.

Dose-response relationship

All three PA parameters were significantly related to depressive symptoms and two of three PA parameters (steps and high-cadence minutes) were significantly related to treatment for depression and anxiety when evaluated as continuous measures, indicating a dose-response relationship with PA. These findings are in line with results from the National Comorbidity Survey (n=8098), in which frequency of PA (without regard for duration) showed a dose-response relationship with current major depression and anxiety disorders (51); a randomized control trial of adults with elevated depressive symptoms (n=23), in which high-frequency aerobic exercise (i.e. 3-5 sessions/week) was more efficacious in reducing depressive symptoms compared to low-frequency aerobic exercise (of the same duration) (52); as well as a study of adults with major depressive disorder (n=53) who had larger increases in their positive affect after longer duration and/or higher intensity PA compared to short duration and/or lower intensity PA (53). However, given the cross sectional nature of this study, it is unclear whether greater volumes of PA resulted in better mental health (i.e., fewer depressive symptoms, less need for treatment for depression and anxiety) or whether poor mental health resulted in less PA.

PA intensity

Some, but not all, studies suggest that more intense PA leads to greater antidepressant effects compared to less intense PA (54). Thus, an important feature of this study was the inclusion of several parameters of PA, which differed by PA intensity. The classification accuracy (as shown by the C statistic) in predicting depressive symptoms and treatment for depression and anxiety was highest with high-cadence minutes, a proxy measure for moderate-vigorous intensity PA, compared to active minutes or steps, which do not account for PA intensity. Therefore, this study provides support that the association between PA and depression and anxiety may be stronger with higher-intensity PA.

Confounders/mediators

After controlling for bodily pain and role limitations due to physical problems, associations between PA parameters and depressive symptoms were no longer significant. It is possible that they confounded the relationship (i.e., pain and physical health factors may have limited PA, while also independently increasing depressive symptoms (55). However, it is also possible that pain and physical role limitations mediated the relationship between PA and depressive symptoms, given that PA participation can decrease pain and improve physical health, thereby lessoning role limitations due to physical problems (56).

Mechanisms

There are several physiological mechanisms that may account for a positive association between PA and mental health in adults with severe obesity. Exercise stimulates serotonin release (53) and reduces the stress hormone cortisol (57), both of which can positively influence mood states. Exercise may also stimulate growth of new nerve cells and release of proteins known to improve health and survival of nerve cells, such as brain-derived neurotrophic factor messenger ribonucleic acid in the hippocampus, an important brain area for behavioral regulation (58;59). It has also been hypothesized that exercise attenuates the hypothalamic-pituitary-adrenal axis response to physical and mental stress (60). Additional physiological or biochemical explanations for how PA may improve aspects of mental health include endogenous opiates, endocannabinoids, anti-inflammatory cytokines, and cerebral blood flow (61). Psychological factors associated with PA participation may also reduce symptoms of depression or anxiety in adults with severe obesity. For example, exercise participation is associated with greater confidence in the capacity of one’s body, perceptions of competence, self-efficacy and improved body image (61;62). Thus, exercise may influence depression through enhanced self-esteem. Exercise may also provide patients, who may be lacking a sense of control, with a sense of self-determination (61), thereby reducing anxiety. Exercise may also serve as a distraction from worries and negative thoughts (63). These mechanisms are not mutually exclusive; the effects of PA might stimulate a complex system, trigger a cascade of physiological and neurobiological events (23).

Threshold effect

Although the 2008 PA guidelines for Americans recommend that adults participate in at least 150 minutes/week of moderate-vigorous intensity PA to gain general health benefits, they recognize that “the specific amounts and types of activity that benefit each [health] condition vary” (64). Thus, we sought to determine thresholds of PA parameters that best differentiated those with versus without indication of poor mental health using ROC analysis. None of the PA parameters we evaluated were associated with impaired mental health functioning, as measured by the SF-36, perhaps because the amount and/or type of PA that may be required to impact mental health functioning was not represented in this observational study. Thus, this analysis was limited to depressive symptoms and treatment for depression and anxiety. The thresholds of PA identified in this study were quite low. For example, daily step thresholds were 5740 steps and 4750 steps for depressive symptoms and recent treatment for depression or anxiety, respectively, which are indicative of “low” and “sedentary” PA levels, respectively (65). Similarly, the thresholds of high-cadence minutes for depressive symptoms and treatment for depression and anxiety (4.7 minutes/day and 8.1 minutes/day, respectively, which translate into approximately 30 minutes and 1 hour of moderate-vigorous intensity PA/week, respectively), were far lower than the minimum level of moderate-vigorous intensity PA recommended for adults (64). However, the low thresholds identified in this study may be an artifact of the low representation of higher levels of PA in this observational study. It is also important to recognize that the thresholds of PA that we identified are not necessarily sufficient for treating major depressive disorder or an anxiety disorder. A randomized clinical trial would be required to test the efficacy of various doses of PA for reducing symptoms of depression and anxiety in adults with severe obesity.

Strengths and limitations

Major strengths of this study were its use of a high-quality PA monitor that is reliable and valid in obese populations, and inclusion of three PA parameters that measured different aspects of ambulatory PA. However, it should be noted that this study was unable to investigate whether non-ambulatory “mindful” exercise, such as yoga, were related to mental health. A major limitation of this study is its cross sectional design, which limits us from deducing causality. Although the observed associations between PA and mental health indicators could reflect the beneficial effects of greater amounts of PA, they could also reflect that patients with more severe depressive symptoms or who require more treatment for depression and anxiety are less likely to be physically active. For example depression or anxiety may cause people to be more socially isolated and less motivated to engage in PA. In addition, while validated surveys allowed for assessment of mental health functioning and depressive symptoms, this study lacked clinical diagnosis of depression or anxiety. Recent treatment for depression or anxiety was used as a proxy for having depression or anxiety, although severity of symptoms does not necessarily dictate whether treatment is sought by patients, offered by health professionals or accepted by patients, and may be representative of better access to mental health care or increased effort to prepare for bariatric surgery. Finally, it is possible that counseling for depression or anxiety (reported by 46.5% of those who received treatment) included advice to increase PA. However, such advice would presumably decrease the strength of the associations found in this study.

Conclusion

This study revealed an inverse association between rather modest levels of PA and depressive symptoms and recent treatment for depression or anxiety, in a large cohort of adults with class 2 and 3 obesity undergoing bariatric surgery at one of 10 hospitals throughout the U.S. Although causality cannot be established, our findings are encouraging and should leverage further investigation of the role of PA in prevention and treatment of depression and anxiety in adults with class 2 and 3 obesity, as PA may prove to be a comparatively safe and cost-effective treatment option. Future research investigating the clinical effects of PA in this population should investigate the optimal type, intensity, frequency and duration of PA. In particular, it would be worthwhile to determine whether increasing the PA level of bariatric surgery candidates from sedentary to low active (e.g., meeting the thresholds of PA identified in this study) has an impact on symptoms of depression or anxiety, or whether, as has been found in some other populations, a higher dose of PA is required. Future research should also evaluate both short and long-term changes in symptoms, as well as changes in weight loss and quality of life following bariatric surgery.

Acknowledgements

LABS personnel contributing to the study include: Columbia University Medical Center, New York, NY: Paul D. Berk, MD, Marc Bessler, MD, Amna Daud, Harrison Lobdell IV, Jemela Mwelu, Beth Schrope, MD, PhD, Akuezunkpa Ude, MD Cornell University Medical Center, New York, NY: Michelle Capasso, BA, Ricardo Costa, BS, Greg Dakin, MD, Faith Ebel RD, MPH, Michel Gagner, MD, Jane Hsieh BS, Alfons Pomp, MD, Gladys Strain, PhD Mt. Sinai Medical Center, New York, NY: W. Barry Inabnet, MD East Carolina Medical Center, Greenville, NC: Rita Bowden, RN, William Chapman, MD, FACS, Lynis Dohm, PhD, John Pender MD, Walter Pories, MD, FACS Neuropsychiatric Research Institute, Fargo, ND: Jennifer Barker, MBA, Michael Howell, MD, Luis Garcia, MD, FACS, MBA, Kathy Lancaster, BA, Erika Lovaas, BS, James E. Mitchell, MD, Tim Monson, MD Oregon Health & Science University: Chelsea Cassady, BS, Clifford Deveney, MD, Katherine Elder, PhD, Andrew Fredette, BA, Stefanie Greene, Jonathan Purnell, MD, Robert O’Rourke, MD, Lynette Rogers, Chad Sorenson, Bruce M. Wolfe, MD Legacy Good Samaritan Hospital, Portland, OR: Emma Patterson, MD, Mark Smith, MD, William Raum, MD, Lisa VanDerWerff, PAC, Jason Kwiatkowski, PAC, Jamie Laut, MEd Sacramento Bariatric Medical Associates, Sacramento, CA: Iselin Austrheim-Smith, CCRP, Laura Machado, MD University of Pittsburgh Medical Center, Pittsburgh, PA: Chris Costa, BA Anita P. Courcoulas, MD, MPH, FACS, Jessie Eagleton , BS, George Eid, MD, William Gourash, MSN, CRNP, Lewis H. Kuller, MD, DrPH, Carol A. McCloskey, MD, Ramesh Ramanathan, MD, Rebecca Search, MPH, Eleanor Shirley, MA University of Washington, Seattle, WA: David E. Cummings, MD, E. Patchen Dellinger, MD, Hallie Ericson, BA, David R. Flum, MD, MPH, Katrina Golub, MPH, CCRC, Brant Oelschlager, MD, Skye Steptoe, MS, CCRC, Tomio Tran, Andrew Wright, MD Virginia Mason Medical Center, Seattle, WA: Lily Chang, MD, Stephen Geary, RN, Jeffrey Hunter, MD, Anne MacDougall, BA Ravi Moonka, MD, Olivia A. Seibenick, CCRC, Richard Thirlby, MD Data Coordinating Center, Graduate School of Public Health at the University of Pittsburgh, Pittsburgh, PA: Abi Adenijii, PhD, Steven H. Belle, PhD, MScHyg, Nicholas Christian, PhD, Lily (Jia-Yuh) Chen, MS, Michelle Fouse, BS, Jesse Hsu, PhD, Laurie Iacono, MFA, Wendy C. King, PhD, Kevin Kip, PhD, Kira Leishear, PhD, Debbie Martin, BA, Rocco Mercurio, MBA, Faith Selzer, PhD, Abdus Wahed, PhD National Institute of Diabetes and Digestive and Kidney Diseases: Mary Evans, Ph.D, Mary Horlick, MD, Carolyn W. Miles, PhD, Myrlene A. Staten, MD, Susan Z. Yanovski, MD National Cancer Institute: David E. Kleiner, MD, PhD.

Funding

The LABS-2 study was funded by a cooperative agreement by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Grant numbers: Data Coordinating Center -U01 DK066557; Columbia-Presbyterian - U01-DK66667 (in collaboration with Cornell University Medical Center CTSC, Grant UL1-RR024996); University of Washington - U01-DK66568 (in collaboration with CTRC, Grant M01RR-00037); Neuropsychiatric Research Institute - U01-DK66471; East Carolina University – U01-DK66526; University of Pittsburgh Medical Center – U01-DK66585 (in collaboration with CTRC, Grant UL1-RR024153); Oregon Health & Science University – U01-DK66555.

Role of the Sponsor

NIDDK scientists contributed to the design and conduct of the study, which included collection, and management of data. The Project Scientist from NIDDK served as a member of the Steering Committee, along with the Principal Investigator from each clinical site and the Data Coordinating Center (DCC). The DCC housed all data during the study and performed data analyses according to a pre-specified plan developed by the DCC biostatistician and approved by the steering committee and independent Data Safety Monitoring Board. This report was written without input from the sponsor. The decision to publish was made by the LABS steering committee, with no restrictions imposed by the sponsor.

Footnotes

Competing Interest Statement

All authors have completed the Unified Competing Interest form at http://www.icmje.org/coi_disclosure.pdf and have no competing interests to report.

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Contributor Information

Wendy C. King, University of Pittsburgh, Graduate School of Public Health, Department of Epidemiology, Pittsburgh.

Melissa A. Kalarchian, Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh.

Kristine J. Steffen, Neuropsychiatric Research Institute, Fargo.

Bruce M. Wolfe, Oregon Health and Science University, Department of Surgery, Portland.

Katherine A. Elder, Pacific University, School of Professional Psychology, Portland.

James E. Mitchell, Neuropsychiatric Research Institute, Fargo.

References

  • [1].Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJ. Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. Lancet. 2006;367(9524):1747–1757. doi: 10.1016/S0140-6736(06)68770-9. [DOI] [PubMed] [Google Scholar]
  • [2].Barry D, Pietrzak RH, Petry NM. Gender differences in associations between body mass index and DSM-IV mood and anxiety disorders: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Ann Epidemiol. 2008;18(6):458–466. doi: 10.1016/j.annepidem.2007.12.009. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [3].Becker ES, Margraf J, Turke V, Soeder U, Neumer S. Obesity and mental illness in a representative sample of young women. Int J Obes Relat Metab Disord. 2001;25(Suppl 1):S5–S9. doi: 10.1038/sj.ijo.0801688. [DOI] [PubMed] [Google Scholar]
  • [4].Mather AA, Cox BJ, Enns MW, Sareen J. Associations of obesity with psychiatric disorders and suicidal behaviors in a nationally representative sample. J Psychosom Res. 2009;66(4):277–285. doi: 10.1016/j.jpsychores.2008.09.008. [DOI] [PubMed] [Google Scholar]
  • [5].Onyike CU, Crum RM, Lee HB, Lyketsos CG, Eaton WW. Is obesity associated with major depression? Results from the Third National Health and Nutrition Examination Survey. Am J Epidemiol. 2003;158(12):1139–1147. doi: 10.1093/aje/kwg275. [DOI] [PubMed] [Google Scholar]
  • [6].Petry NM, Barry D, Pietrzak RH, Wagner JA. Overweight and obesity are associated with psychiatric disorders: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Psychosom Med. 2008;70(3):288–297. doi: 10.1097/PSY.0b013e3181651651. [DOI] [PubMed] [Google Scholar]
  • [7].Scott KM, McGee MA, Wells JE, Oakley Browne MA. Obesity and mental disorders in the adult general population. J Psychosom Res. 2008;64(1):97–105. doi: 10.1016/j.jpsychores.2007.09.006. [DOI] [PubMed] [Google Scholar]
  • [8].Simon GE, Von Korff M, Saunders K, Miglioretti DL, Crane PK, van Belle G, et al. Association between obesity and psychiatric disorders in the US adult population. Arch Gen Psychiatry. 2006;63(7):824–830. doi: 10.1001/archpsyc.63.7.824. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [9].de Wit L, Luppino F, van Straten A, Penninx B, Zitman F, Cuijpers P. Depression and obesity: a meta-analysis of community-based studies. Psychiatry Res. 2010;178(2):230–235. doi: 10.1016/j.psychres.2009.04.015. [DOI] [PubMed] [Google Scholar]
  • [10].Dixon JB, Dixon ME, O’Brien PE. Depression in association with severe obesity: changes with weight loss. Arch Intern Med. 2003;163(17):2058–2065. doi: 10.1001/archinte.163.17.2058. [DOI] [PubMed] [Google Scholar]
  • [11].Pingitore R, Spring B, Garfield D. Gender differences in body satisfaction. Obes Res. 1997;5(5):402–409. doi: 10.1002/j.1550-8528.1997.tb00662.x. [DOI] [PubMed] [Google Scholar]
  • [12].Chen EY, Brown M. Obesity stigma in sexual relationships. Obes Res. 2005;13(8):1393–1397. doi: 10.1038/oby.2005.168. [DOI] [PubMed] [Google Scholar]
  • [13].Puhl RM, Heuer CA. Obesity stigma: important considerations for public health. Am J Public Health. 2010;100(6):1019–1028. doi: 10.2105/AJPH.2009.159491. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [14].Roehling MV. Weight-based discrimination in employment: psychological and legal aspects. Personnel Psychol. 1999;52:969–1017. [Google Scholar]
  • [15].Kalarchian MA, Marcus MD, Levine MD, et al. Psychiatric disorders among bariatric surgery candidates: relationship to obesity and functional health status. Am J Psychiatry. 2007;164(2):328–334. doi: 10.1176/ajp.2007.164.2.328. [DOI] [PubMed] [Google Scholar]
  • [16].Muhlhans B, Horbach T, de Zwaan M. Psychiatric disorders in bariatric surgery candidates: a review of the literature and results of a German prebariatric surgery sample. Gen Hosp Psychiatry. 2009;31(5):414–421. doi: 10.1016/j.genhosppsych.2009.05.004. [DOI] [PubMed] [Google Scholar]
  • [17].Karlsson J, Sjostrom L, Sullivan M. Swedish obese subjects (SOS)--an intervention study of obesity. Two-year follow-up of health-related quality of life (HRQL) and eating behavior after gastric surgery for severe obesity. Int J Obes Relat Metab Disord. 1998;22(2):113–126. doi: 10.1038/sj.ijo.0800553. [DOI] [PubMed] [Google Scholar]
  • [18].de Zwaan M, Enderle J, Wagner S, Muhlhans B, Ditzen B, Gefeller O, et al. Anxiety and depression in bariatric surgery patients: a prospective, follow-up study using structured clinical interviews. J Affect Disord. 2011;133(1-2):61–68. doi: 10.1016/j.jad.2011.03.025. [DOI] [PubMed] [Google Scholar]
  • [19].Rojas C, Brante M, Miranda E, Perez-Luco R. Anxiety, depression and self-concept among morbid obese patients before and after bariatric surgery] Rev Med Chil. 2011;139(5):571–578. [PubMed] [Google Scholar]
  • [20].Lier HO, Biringer E, Stubhaug B, Tangen T. Prevalence of psychiatric disorders before and 1 year after bariatric surgery: The role of shame in maintenance of psychiatric disorders in patients undergoing bariatric surgery. Nord J Psychiatry. 2012 May 16; doi: 10.3109/08039488.2012.684703. [Epub ahead of print] [DOI] [PubMed] [Google Scholar]
  • [21].Legenbauer T, de Zwaan M, Benecke A, Muhlhans B, Petrak F, Herpertz S. Depression and anxiety: their predictive function for weight loss in obese individuals. Obes Facts. 2009;2(4):227–234. doi: 10.1159/000226278. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [22].Kinzl JF, Schrattenecker M, Traweger C, Mattesich M, Fiala M, Biebl W. Psychosocial predictors of weight loss after bariatric surgery. Obes Surg. 2006;16(12):1609–1614. doi: 10.1381/096089206779319301. [DOI] [PubMed] [Google Scholar]
  • [23].Strohle A. Physical activity, exercise, depression and anxiety disorders. J Neural Transm. 2009;116(6):777–784. doi: 10.1007/s00702-008-0092-x. [DOI] [PubMed] [Google Scholar]
  • [24].Conn VS. Depressive Symptom Outcomes of Physical Activity Interventions: Meta-analysis Findings. Ann Behav Med. 2010;39(2):128–38. doi: 10.1007/s12160-010-9172-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [25].Herring MP, Puetz TW, O’Connor PJ, Dishman RK. Effect of exercise training on depressive symptoms among patients with a chronic illness: a systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2012;172(2):101–11. doi: 10.1001/archinternmed.2011.696. [DOI] [PubMed] [Google Scholar]
  • [26].Carek PJ, Laibstain SE, Carek SM. Exercise for the treatment of depression and anxiety. Int J Psychiatry Med. 2011;41(1):15–28. doi: 10.2190/PM.41.1.c. [DOI] [PubMed] [Google Scholar]
  • [27].Krogh J, Nordentoft M, Sterne JA, Lawlor DA. The effect of exercise in clinically depressed adults: systematic review and meta-analysis of randomized controlled trials. J Clin Psychiatry. 2011;72(4):529–38. doi: 10.4088/JCP.08r04913blu. [DOI] [PubMed] [Google Scholar]
  • [28].Rethorst CD, Wipfli BM, Landers DM. The Antidepressive Effects of Exericse. Sports Med. 2009;39(6):491–511. doi: 10.2165/00007256-200939060-00004. [DOI] [PubMed] [Google Scholar]
  • [29].Rimer J, Dwan K, Lawlor DA, Greig CA, McMurdo M, Morley W, Mead GE. Exercise for depression. Cochrane Database Syst Rev. 2012;7:CD004366. doi: 10.1002/14651858.CD004366.pub5. [DOI] [PubMed] [Google Scholar]
  • [30].Dinas PC, Koutedakis Y, Flouris AD. Effects of exercise and physical activity on depression. Ir J Med Sci. 2011;180(2):319–325. doi: 10.1007/s11845-010-0633-9. [DOI] [PubMed] [Google Scholar]
  • [31].Gusi N, Reyes MC, Gonzalez-Guerrero JL, Herrera E, Garcia JM. Cost-utility of a walking programme for moderately depressed, obese, or overweight elderly women in primary care: A randomized controlled trial. BMC Public Health. 2008;8:231–240. doi: 10.1186/1471-2458-8-231. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [32].Sarsan A, Ardic F, Ozgen M, Topuz O, Sermez Y. The effects of aerobic and resistance exercise in obese women. Clin Rehabil. 2006;20(9):773–782. doi: 10.1177/0269215506070795. [DOI] [PubMed] [Google Scholar]
  • [33].Nieman DC, Custer WF, Butterworth DE, Utter AC, Henson DA. Psychological response to exercise training and/or energy restriction in obese women. J Psychosom Res. 2000;48(1):23–29. doi: 10.1016/s0022-3999(99)00066-5. [DOI] [PubMed] [Google Scholar]
  • [34].Bond DS, Evans RK, DeMaria E, Wolfe L, Meador J, Kellum J, Maher J, Warren BJ. Physical activity and quality of life improvements before obesity surgery. Am J Health Behav. 2006;30(4):422–34. doi: 10.5555/ajhb.2006.30.4.422. [DOI] [PubMed] [Google Scholar]
  • [35].Bond DS, Phelan S, Wolfe LG, Evans RK, Meador JG, Kellum JM, Maher JW, Wing RR. Becoming physically active after bariatric surgery is associated with improved weight loss and health-related quality of life. Obesity (Silver Spring) 2009;1 doi: 10.1038/oby.2008.501. [DOI] [PubMed] [Google Scholar]
  • [36].Rosenberger PH, Henderson KE, White MA, Masheb RM, Grilo CM. Physical activity in gastric bypass patients: associations with weight loss and psychosocial functioning at 12-month follow-up. Obes Surg. 2011;21(10):1564–9. doi: 10.1007/s11695-010-0283-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [37].Larsen JK, Geenen R, van Ramshorst B, Brand N, Hox JJ, Stroebe W, van Doornen LJ. Binge eating and exercise behavior after surgery for severe obesity: a structural equation model. Int J Eat Disord. 2006;39(5):369–75. doi: 10.1002/eat.20249. [DOI] [PubMed] [Google Scholar]
  • [38].Belle S, Berk PD, Courcoulas A, Flum D, Miles C, Mitchell J, et al. Safety and efficacy of bariatric surgery: Longitudinal Assessment of Bariatric Surgery. Surg Obes Relat Dis. 2007;3(2):116–126. doi: 10.1016/j.soard.2007.01.006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [39].Boone DA, Coleman KL. Use of a Step Activity Monitor in determining outcomes. JPO. 2006;18(1S):86–92. [Google Scholar]
  • [40].King WC, Li J, Leishear K, Mitchell JE, Belle SH. Determining activity monitor wear time: an influential decision rule. J Phys Act Health. 2011;8(4):566–580. doi: 10.1123/jpah.8.4.566. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [41].Ware JE, Jr., Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care. 1992;30(6):473–483. [PubMed] [Google Scholar]
  • [42].Ware JE, Jr., Kosinski M, Keller SK. SF-36® physical and mental health summary scales: a user’s manual. The Health Institute; Boston, MA: 1994. [Google Scholar]
  • [43].Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry. 1961;4:561–571. doi: 10.1001/archpsyc.1961.01710120031004. [DOI] [PubMed] [Google Scholar]
  • [44].Beck AT, Steer RA, Garbin MG. Psychometric properties of the Beck Depression Inventory. Twenty-five years of evaluation. Clin Psychol Rev. 1998;8:77–100. [Google Scholar]
  • [45].Walfish S, Vance D, Fabricatore AN. Psychological evaluation of bariatric surgery applicants: procedures and reasons for delay or denial of surgery. Obes Surg. 2007;17(12):1578–1583. doi: 10.1007/s11695-007-9274-0. [DOI] [PubMed] [Google Scholar]
  • [46].Fabricatore AN, Wadden TA, Sarwer DB, Faith MS. Health-related quality of life and symptoms of depression in extremely obese persons seeking bariatric surgery. Obes Surg. 2005;15(3):304–309. doi: 10.1381/0960892053576578. [DOI] [PubMed] [Google Scholar]
  • [47].Harvey SB, Hotopf M, Overland S, Mykletun A. Physical activity and common mental disorders. Br J Psychiatry. 2010;197(5):357–364. doi: 10.1192/bjp.bp.109.075176. [DOI] [PubMed] [Google Scholar]
  • [48].Barbor TF, Higgins-Biddle JC, Saunders JB, Monteiro MG. AUDIT The Alcohol Use Disorders Identification Test: Guidelines for Use in Primary Care. 2nd Edition WHO/MSD/MSB World Health Organization; Geneva: 2001. [Google Scholar]
  • [49].King WC, Chen JY, Mitchell JE, Kalarchian MA, Steffen KJ, Engel SG, et al. Prevalence of alcohol use disorders before and after bariatric surgery. JAMA. 2012;307(23):2516–2525. doi: 10.1001/jama.2012.6147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [50].McHorney CA, Ware JE, Jr., Raczek AE. The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Med Care. 1993;31(3):247–263. doi: 10.1097/00005650-199303000-00006. [DOI] [PubMed] [Google Scholar]
  • [51].Goodwin RD. Association between physical activity and mental disorders among adults in the United States. Prev Med. 2003;36(6):698–703. doi: 10.1016/s0091-7435(03)00042-2. [DOI] [PubMed] [Google Scholar]
  • [52].Legrand F, Heuze JP. Antidepressant effects associated with different exercise conditions in participants with depression: a pilot study. J Sport Exerc Psychol. 2007;29(3):348–364. doi: 10.1123/jsep.29.3.348. [DOI] [PubMed] [Google Scholar]
  • [53].Mata J, Thompson RJ, Jaeggi SM, Buschkuehl M, Jonides J, Gotlib IH. Walk on the bright side: physical activity and affect in major depressive disorder. J Abnorm Psychol. 2012;121(2):297–308. doi: 10.1037/a0023533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [54].Dunn AL, Trivedi MH, O’Neal HA. Physical activity dose-response effects on outcomes of depression and anxiety. Med Sci Sports Exerc. 2001;33(6 Suppl):S587–S597. doi: 10.1097/00005768-200106001-00027. [DOI] [PubMed] [Google Scholar]
  • [55].Harvey SB, Ismail K. Psychiatric aspects of chronic physical disease. Medicine. 2008;3(9):471–474. [Google Scholar]
  • [56].Pisters MF, Veenhof C, van Meeteren NL, et al. Long-term effectiveness of exercise therapy in patients with osteoarthritis of the hip or knee: a systematic review. Arthritis Rheum. 2007;57(7):1245–1253. doi: 10.1002/art.23009. [DOI] [PubMed] [Google Scholar]
  • [57].Duclos M, Gouarne C, Bonnemaison D. Acute and chronic effects of exercise on tissue sensitivity to glucocorticoids. J Appl Physiol. 2003 Mar;94(3):869–75. doi: 10.1152/japplphysiol.00108.2002. [DOI] [PubMed] [Google Scholar]
  • [58].Dishman RK, O’Connor PJ. Lessons in exercise neurobiology: the case for endorphins. Ment Health Phys Act. 2009;2(1):4–9. [Google Scholar]
  • [59].Russo-Neustadt AA, Beard RC, Huang YM, Cotman CW. Physical activity and antidepressant treatment potentiate the expression of specific brain-derived neurotrophic factor transcripts in the rat hippocampus. Neuroscience. 2000;101(2):305–312. doi: 10.1016/s0306-4522(00)00349-3. [DOI] [PubMed] [Google Scholar]
  • [60].Wittert GA, Livesey JH, Espiner EA, et al. Adaptation of the hypothalamopituitary adrenal axis to chronic exercise stress in humans. Med Sci Sport Exerc. 1996;28(8):1015–9. doi: 10.1097/00005768-199608000-00011. [DOI] [PubMed] [Google Scholar]
  • [61].Daley A. Exercise and depression: a review of reviews. J Clin Psychol Med Settings. 2008;15(2):140–7. doi: 10.1007/s10880-008-9105-z. [DOI] [PubMed] [Google Scholar]
  • [62].Motl RW, Konopack JF, McAuley E, Elavsky S, Jerome GJ, Marquez DX. Depressive symptoms among older adults: long-term reduction after a physical activity intervention. J Behav Med. 2005;28(4):385–394. doi: 10.1007/s10865-005-9005-5. [DOI] [PubMed] [Google Scholar]
  • [63].Gleser J, Mendelberg H. Exercise and sport in mental health: a review of the literature. Isr J Psychiatry Relat Sci. 1990;27(2):99–112. [PubMed] [Google Scholar]
  • [64].U.S.Department of Health and Human Services . 2008 Physical Activity Guidelines for Americans. U.S. Department of Health and Human Services; Washington, DC: 2008. Physical Activity Has Many Health Benefits; pp. 7–14. [Google Scholar]
  • [65].Tudor-Locke C, Bassett DR., Jr How many steps/day are enough? Preliminary pedometer indices for public health. Sports Med. 2004;34(1):1–8. doi: 10.2165/00007256-200434010-00001. [DOI] [PubMed] [Google Scholar]

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