Cardiorespiratory fitness and response to exercise treatment in depression

BACKGROUND

Exercise improves cardiorespiratory fitness (CRF) and reduces depressive symptoms in people with depression. It is unclear if changes in CRF are a predictor of the antidepressant effect of exercise in people with depression.

AIMS

To investigate whether an increase in CRF is a predictor of depression severity reduction after 12 weeks of exercise (trial registration: DRKS study ID, DRKS00008745).

METHOD

The present study includes participants who took part in vigorous (n = 33), moderate (n = 38) and light (n = 39) intensity exercise and had CRF information (as predicted maximal oxygen uptake, V̇O_2max) collected before and after the intervention. Depression severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). V̇O_2max (L/min) was assessed with the Åstrand-Rhyming submaximal cycle ergometry test. The main analysis was conducted pooling all exercise intensity groups together.

RESULTS

All exercise intensities improved V̇O_2max in people with depression. Regardless of frequency and intensity of exercise, an increase in post-treatment V̇O_2max was significantly associated with reduced depression severity at follow-up (B = -3.52, 95% CI -6.08 to -0.96); adjusting for intensity of exercise, age and body mass index made the association stronger (B = -3.89, 95% CI -6.53 to -1.26). Similarly, increased V̇O_2max was associated with higher odds (odds ratio = 3.73, 95% CI 1.22-11.43) of exercise treatment response (≥50% reduction in MADRS score) at follow-up.

CONCLUSIONS

Our data suggest that improvements in V̇O_2max predict a greater reduction in depression severity among individuals who were clinically depressed. This finding indicates that improvements in V̇O_2max may be a marker for the underpinning biological pathways for the antidepressant effect of exercise.

DECLARATION OF INTEREST

None.

Imaging genetics paradigms in depression research: Systematic review and meta-analysis

Imaging genetics studies involving participants with major depressive disorder (MDD) have expanded. Nevertheless, findings have been inconsistent. Thus, we conducted a systematic review and meta-analysis of imaging genetics studies that enrolled MDD participants across major databases through June 30th, 2017. Sixty-five studies met eligibility criteria (N = 4034 MDD participants and 3293 controls), and there was substantial between-study variability in the methodological quality of included studies. However, few replicated findings emerged from this literature with only 22 studies providing data for meta-analyses (882 participants with MDD and 616 controls). Total hippocampal volumes did not significantly vary in MDD participants or controls carrying either the BDNF Val66Met 'Met' (386 participants with MDD and 376 controls) or the 5-HTTLPR short 'S' (310 participants with MDD and 230 controls) risk alleles compared to non-carriers. Heterogeneity across studies was explored through meta-regression and subgroup analyses. Gender distribution, the use of medications, segmentation methods used to measure the hippocampus, and age emerged as potential sources of heterogeneity across studies that assessed the association of 5-HTTLPR short 'S' alleles and hippocampal volumes. Our data also suggest that the methodological quality of included studies, publication year, and the inclusion of brain volume as a covariate contributed to the heterogeneity of studies that assessed the association of the BDNF Val66Met 'Met' risk allele and hippocampal volumes. In exploratory voxel-wise meta-analyses, MDD participants carrying the 5-HTTLPR short 'S' allele had white matter microstructural abnormalities predominantly in the corpus callosum, while carriers of the BDNF Val66Met 'Met' allele had larger gray matter volumes and hyperactivation of the right middle frontal gyrus compared to non-carriers. In conclusion, few replicated findings emerged from imaging genetics studies that included participants with MDD. Nevertheless, we explored and identified specific sources of heterogeneity across studies, which could provide insights to enhance the reproducibility of this emerging field.

Associations between active travel and physical multi-morbidity in six low- and middle-income countries among community-dwelling older adults: A cross-sectional study

BACKGROUND

There is little evidence on the potential health benefits of active travel in low- and middle-income countries (LMICs). The aim of this study was to assess the association between levels of active travel and physical multi-morbidity (i.e., two or more chronic physical conditions) and individual physical conditions among community-dwelling adults aged 65 or older in six LMICs.

METHODS

Data were analyzed from the World Health Organization's Study on Global Ageing and Adult Health (China, Ghana, India, Mexico, Russia, South Africa). Active travel (minutes / week) was assessed with questions of the Global Physical Activity Questionnaire (GPAQ) and presented in tertiles. Eleven chronic conditions (angina, arthritis, asthma, chronic back pain, chronic lung disease, diabetes, edentulism, hearing problems, hypertension, stroke, visual impairment) were assessed by self-report of diagnosis, symptoms, or blood pressure measurement. Multivariable logistic regression analysis was conducted to assess the association between levels of active travel, physical conditions and physical multi-morbidity.

RESULTS

The final sample consisted of 14,585 individuals aged ≥65 years (mean age = 72.6±0.1 years; 54.9% female). In the fully adjusted model, compared to the highest tertile, those in the lowest tertile of active travel had a 1.28 (95%CI = 1.06-1.54) times higher odds for physical multi-morbidity. The association between active travel and physical multi-morbidity was significantly mediated by affect (14.4%) and cognition (9.7%). With regard to individual conditions, hearing problems, hypertension, stroke, and visual impairment were particularly strongly associated with less active travel.

CONCLUSION

The current data suggest that lower levels of active travel are associated with the presence of physical health conditions and physical multi-morbidity. This multi-national study offers potentially valuable insight for a number of hypotheses which may influence this relationship, although testing with longitudinal studies is needed.

Correlates of sedentary behavior in the general population: A cross-sectional study using nationally representative data from six low- and middle-income countries

Background

Sedentary behavior (SB) is associated with adverse health outcomes independent of levels of physical activity. However, data on its correlates are scarce from low- and middle-income countries (LMICs). Thus, we assessed the correlates of SB in six LMICs (China, Ghana, India, Mexico, Russia, South Africa) using nationally representative data.

Methods

Cross-sectional, community-based data on 42,469 individuals aged ≥18 years from the World Health Organization’s Study on Global Ageing and Adult Health were analyzed. Self-reported time spent sedentary per day was the outcome. High SB was defined as ≥8 hours of SB per day. The correlates (sociodemographic and health-related) of high SB were estimated by multivariable logistic regression analyses.

Results

The overall prevalence (95%CI) of high SB was 8.3% (7.1–9.7%). In the overall sample, the most important sociodemographic correlates of high SB were unemployment and urban residence. Physical inactivity, morbid obesity (BMI≥30.0 kg/m²), higher number of chronic conditions, poor self-reported health, higher disability levels, and worse health status in terms of mobility, pain/discomfort, affect, sleep/energy and cognition were associated with high SB. Several between-country differences were found.

Conclusion

The current data provides important guidance for future interventions across LMICs to assist sedentary people to reduce their SB levels.

Sedentary behavior and depressive symptoms among 67,077 adolescents aged 12-15 years from 30 low- and middle-income countries

BACKGROUND

Depression is common and burdensome in adolescents. Understanding modifiable environmental risk factors is essential. There is evidence that physical activity is protective of depression. However, the impact of sedentary behavior (SB) on depression is relatively under-researched especially in low- and middle-income countries (LMICs). In this cross-sectional study, we explored the association between SB and depressive symptoms in adolescents from 30 LMICs, controlling for confounders including physical activity.

METHOD

Data from the Global school-based Student Health Survey were analyzed in 67,077 adolescents [mean (SD) age 13.8 (0.9) years; 50.6% girls). Self-report measures assessed depressive symptoms during the past 12 months, and SB, which was a composite variable assessing time spent sitting and watching television, playing computer games, talking with friends during a typical day excluding the hours spent sitting at school and doing homework. Multivariable logistic regression analysis was conducted and a countrywide meta-analysis undertaken.

RESULTS

The prevalence of depressive symptoms and ≥ 3 h/day of SB were 28.7 and 30.6%, respectively. There was a linear increase in the prevalence of depressive symptoms with increasing sedentary time beyond ≥3 h/day (vs. < 1 h/day). Among boys, 1-2 h/day of SB was associated with lower odds for depression (vs. < 1 h/day). Countrywide meta-analysis demonstrated that spending ≥3 h/day versus < 3 h/day was associated with a 20% increased odds for depressive symptoms (OR = 1.20; 95% CI = 1.16-1.24) with low between-country heterogeneity (I2 = 27.6%).

CONCLUSION

Our data indicate that being sedentary for ≥3 h/day is associated with increased odds for depressive symptoms in adolescence. Future longitudinal data are required to confirm/refute the findings to inform public interventions which aim to limit the time spent being sedentary in adolescents.

Sedentary behavior and perceived stress among adults aged ≥50 years in six low- and middle-income countries

BACKGROUND

Sedentary behavior and perceived stress are both negatively associated with physical and mental health. Little is known about the association between sedentary behavior and perceived stress, and there is a particular paucity of data on people aged ≥50 years from low- and middle-income countries (LMICs).

METHODS

We analyzed cross-sectional, community-based data from 34,129 individuals aged ≥50 years [mean age 62.4 (SD = 16.0) years, 52% females] from six LMICs. Perceived stress was assessed using the Perceived Stress Scale and time spent sedentary per day was self-reported. Multivariable linear regression analyses were conducted, adjusting for important socio-economic and physical and mental health-related confounders.

RESULTS

The mean perceived stress score increased with greater sedentary time (38.4 for 0-<4 h/day to 54.2 for ≥11 h/day). In the fully adjusted model, 4-8, 8-11, and ≥11 h/day of sedentary behavior (SB) were associated with 1.97 (95%CI = 0.57-3.36), 7.11 (95%CI = 4.96-9.27), and 9.02 (95%CI = 5.45-12.59) times higher mean perceived stress scores, compared with 0-<4 h/day. Greater time spent sedentary was associated with higher perceived stress scores in all six countries, although the association in Mexico fell short of statistical significance.

CONCLUSION

This is the first multinational analysis to show that a greater amount of sedentary behavior is associated with higher levels of perceived stress among older adults in LMICs. Future research may examine the types and contexts of sedentary behavior, and explore the underlying mechanisms of the relationship.

Driving impairment and crash risk in Parkinson disease: A systematic review and meta-analysis

OBJECTIVES

To provide the best possible evidence base for guiding driving decisions in Parkinson disease (PD), we performed a meta-analysis comparing patients with PD to healthy controls (HCs) on naturalistic, on-the-road, and simulator driving outcomes.

METHODS

Seven major databases were systematically searched (to January 2018) for studies comparing patients with PD to HCs on overall driving performance, with data analyzed using random-effects meta-analysis.

RESULTS

Fifty studies comprising 5,410 participants (PD = 1,955, HC = 3,455) met eligibility criteria. Analysis found the odds of on-the-road test failure were 6.16 (95% confidence interval [CI] 3.79-10.03) times higher and the odds of simulator crashes 2.63 (95% CI 1.64-4.22) times higher for people with PD, with poorer overall driving ratings also observed (standardized mean differences from 0.50 to 0.67). However, self-reported real-life crash involvement did not differ between people with PD and HCs (odds ratio = 0.84, 95% CI 0.57-1.23, p = 0.38). Findings remained unchanged after accounting for any differences in age, sex, and driving exposure, and no moderating influence of disease severity was found.

CONCLUSIONS

Our findings provide persuasive evidence for substantive driving impairment in PD, but offer little support for mandated PD-specific relicensure based on self-reported crash data alone, and highlight the need for objective measures of crash involvement.

The relationship between the dietary inflammatory index (DII®) and incident depressive symptoms: A longitudinal cohort study

BACKGROUND

Diet is a common source of inflammation, and inflammation is associated with depression. We examined the association between the dietary inflammatory index (DII^®), a validated measure of inflammatory potential of the diet, and risk of depression in a cohort of older North American adults.

METHODS

This longitudinal study, with a follow-up of 8 years, included 3648 participants (1577 males, 2071 females; mean age: 60.6 years) with/at risk of knee osteoarthritis. DII^® scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire. Center for Epidemiological Studies Depression-20 scale was used to define depressive symptoms. The relationship between baseline DII^® score and incident depression was assessed through Cox's regression analysis, adjusted for potential confounders, and reported as hazard ratios (HRs).

RESULTS

In total, 837 individuals (310 men and 527 women) developed incident depressive symptoms over the course of 8 years. Participants in the most pro-inflammatory group (quartile 4) had approximately 24% higher risk of developing depressive symptoms compared to subjects with the most anti-inflammatory diet (HR: 1.24; 95% CI: 1.01-1.53; p = 0.04).

CONCLUSION

These results suggest that a pro-inflammatory diet may be associated with higher incidence of depressive symptoms in a cohort of older Americans. Transitioning to a more anti-inflammatory diet may reduce depression risk.

Prevalence of Catatonia and Its Moderators in Clinical Samples: Results from a Meta-analysis and Meta-regression Analysis

Catatonia is an independent syndrome that co-occurs with several mental and medical conditions. We performed a systematic literature review in PubMed/Scopus until February 2017 and meta-analyzed studies reporting catatonia prevalence. Across 74 studies (cross-sectional = 32, longitudinal = 26, retrospective = 16) providing data collected from 1935 to 2017 across all continents, mean catatonia prevalence was 9.0% (k = 80, n = 110764; 95% CI = 6.9-11.7, I2 = 98%, publication bias P < .01), decreasing to 7.8% (k = 19, n = 7612, 95% CI = 7-8.7, I2 = 38.9%) in a subgroup with low heterogeneity. Catatonia prevalence was 23.9% (k = 8, n = 1168, 95% CI = 10-46.9, I2 = 96%) in patients undergoing ECT/having elevated creatinine phosphokinase. Excluding ECT samples, the catatonia prevalence was 8.1% (k = 72, n = 109606, 95% CI = 6.1-10.5, I2 = 98%, publication bias P < .01), with sensitivity analyses demonstrating that country of study origin (P < .001), treatment setting (P = .003), main underlying condition (P < .001), and sample size (P < .001)moderated catatonia prevalence, being highest in Uganda (48.5%, k = 1) and lowest in Mexico (1.9%, 95% CI = 0.4-8.8, I2 = 67%, k = 2), highest in nonpsychiatric out- or inpatient services (15.8%, 95% CI = 8.1-28.4, I2 = 97%, k = 15)and lowest in psychiatric outpatients services (3.2%, 95% CI = 1.7-6.1, I2 = 50%, k = 3), highest in presence of medical or neurological illness with no comorbid psychiatric condition (20.6%, 95% CI = 11.5-34.2, I2 = 95%, k = 10)and lowest in mixed psychiatric samples (5.7%, 95% CI = 4.2-7.7, I2 =98%, k = 43), highest in studies with sample sizes <100 (20.7%, 95% CI = 12.8-31.6, I2 = 90%, k = 17) and lowest in studies with sample sizes >1000 (2.3%, 95% CI = 1.3-3.9, I2 = 99%, k = 16). Meta-regression showed that smaller sample size (P < .01) and less major depressive disorder (P = .02) moderated higher catatonia prevalence. Year of data collection did not significantly moderate the results. Results from this first meta-analysis of catatonia frequencies across time and disorders suggest that catatonia is an epidemiologically and clinically relevant condition that occurs throughout several mental and medical conditions, whose prevalence has not decreased over time and does not seem to depend on different rating scales/criteria. However, results were highly heterogeneous, calling for a cautious interpretation.

Association between depression and smoking: A global perspective from 48 low- and middle-income countries

BACKGROUND

Smoking is a leading modifiable cause of global morbidity and mortality. Research from high-income countries has found a high prevalence of smoking among people with depression and suggested that this may partially contribute to the increased premature mortality in this population. Limited research has investigated smoking behaviors across the depression spectrum and in low- and middle-income countries (LMICs). This study explored the relationship between depression and smoking across 48 LMICs.

METHODS

We conducted a cross-sectional, community-based study comprising 242,952 people [mean age 38.4 (SD = 16.1) years, 50.8% females] from the World Health Survey. Multivariable binary logistic regression analyses were performed to investigate the relationship between depression (including subsyndromal, brief depressive episode and depressive episodes) and smoking behaviours.

RESULTS

Overall, the prevalence of current smoking was lowest in Africa (13.5%) and highest in Asia (32.2%). A depressive episode was present in 6.7% of the sample. Compared to people without depression, subsyndromal depression, brief depressive episode, and depressive episodes were all significantly associated with smoking with similar effect sizes (ORs: 1.36-1.49). Countrywide meta-analysis found that the pooled overall OR for smoking in depression was 1.42 (95%CI = 1.32-1.52, I² = 39.7%). Furthermore, alcohol consumption and male gender were consistently associated with smoking across all regions and smoking was consistently less common in those who were wealthier and had a higher education.

CONCLUSION

These data suggest that the depression spectrum is consistently associated with high levels of smoking behaivours in LMICs. Given that most of the world's smokers reside in LMICs, future smoking cessation interventions are required to target people with depression.

Mapping risk factors for depression across the lifespan: An umbrella review of evidence from meta-analyses and Mendelian randomization studies

The development of depression may involve a complex interplay of environmental and genetic risk factors. PubMed and PsycInfo databases were searched from inception through August 3, 2017, to identify meta-analyses and Mendelian randomization (MR) studies of environmental risk factors associated with depression. For each eligible meta-analysis, we estimated the summary effect size and its 95% confidence interval (CI) by random-effects modeling, the 95% prediction interval, heterogeneity with I², and evidence of small-study effects and excess significance bias. Seventy meta-analytic reviews met the eligibility criteria and provided 134 meta-analyses for associations from 1283 primary studies. While 109 associations were nominally significant (P < 0.05), only 8 met the criteria for convincing evidence and, when limited to prospective studies, convincing evidence was found in 6 (widowhood, physical abuse during childhood, obesity, having 4-5 metabolic risk factors, sexual dysfunction, job strain). In studies in which depression was assessed through a structured diagnostic interview, only associations with widowhood, job strain, and being a Gulf War veteran were supported by convincing evidence. Additionally, 8 MR studies were included and provided no consistent evidence for the causal effects of obesity, smoking, and alcohol consumption. The proportion of variance explained by genetic risk factors was extremely small (0.1-0.4%), which limited the evidence provided by the MR studies. Our findings suggest that despite the large number of putative risk factors investigated in the literature, few associations were supported by robust evidence. The current findings may have clinical and research implications for the early identification of individuals at risk for depression.

Moving to Beat Anxiety: Epidemiology and Therapeutic Issues with Physical Activity for Anxiety

PURPOSE OF REVIEW

The purpose of this paper was to provide a comprehensive narrative review of the relationship between physical activity (PA) and anxiety and the rationale for including it as a treatment option for anxiety disorders. Several gaps in the literature are highlighted alongside recommendations for future research.

RECENT FINDINGS

PA in the general population has established efficacy in preventing and managing cardiovascular disease and improving wellbeing. Recent epidemiological data further suggests that people who are more active may be less likely to have anxiety disorders. In addition, evidence from systematic reviews of randomised control trials suggests that exercise training, a subset of PA, can reduce symptoms in anxiety and stress-related disorders, such as post-traumatic stress disorder, agoraphobia and panic disorder. Anxiety disorders are common, burdensome and costly to individuals and wider society. In addition to the profound negative impact on individuals' wellbeing and functioning, they are associated with worsened physical health, including a higher risk for cardiovascular diseases and premature mortality. Although pharmacotherapy and psychological interventions are helpful for many, these treatment approaches are not effective for everyone and are insufficient to address common physical health complications, such as the elevated risk of cardiovascular disease. Given the combined anxiolytic and physical health benefits of increased activity, PA presents a promising additional treatment option for people with anxiety disorders. However, there remain key gaps in the literature regarding the mechanisms underlying the effects of PA, optimal PA protocols, methods of improving adherence and the importance of physical fitness. These must be addressed for PA to be successfully implemented in mental health services.

The association of depression and all-cause and cause-specific mortality: an umbrella review of systematic reviews and meta-analyses

BACKGROUND

Depression is a prevalent and disabling mental disorder that frequently co-occurs with a wide range of chronic conditions. Evidence has suggested that depression could be associated with excess all-cause mortality across different settings and populations, although the causality of these associations remains unclear.

METHODS

We conducted an umbrella review of systematic reviews and meta-analyses of observational studies. PubMed, PsycINFO, and Embase electronic databases were searched through January 20, 2018. Systematic reviews and meta-analyses that investigated associations of depression and all-cause and cause-specific mortality were selected for the review. The evidence was graded as convincing, highly suggestive, suggestive, or weak based on quantitative criteria that included an assessment of heterogeneity, 95% prediction intervals, small-study effects, and excess significance bias.

RESULTS

A total of 26 references providing 2 systematic reviews and data for 17 meta-analytic estimates met inclusion criteria (19 of them on all-cause mortality); data from 246 unique studies (N = 3,825,380) were synthesized. All 17 associations had P < 0.05 per random effects summary effects, but none of them met criteria for convincing evidence. Associations of depression and all-cause mortality in patients after acute myocardial infarction, in individuals with heart failure, in cancer patients as well as in samples from mixed settings met criteria for highly suggestive evidence. However, none of the associations remained supported by highly suggestive evidence in sensitivity analyses that considered studies employing structured diagnostic interviews. In addition, associations of depression and all-cause mortality in cancer and post-acute myocardial infarction samples were supported only by suggestive evidence when studies that tried to adjust for potential confounders were considered.

CONCLUSIONS

Even though associations between depression and mortality have nominally significant results in all assessed settings and populations, the evidence becomes weaker when focusing on studies that used structured interviews and those that tried to adjust for potential confounders. A causal effect of depression on all-cause and cause-specific mortality remains unproven, and thus interventions targeting depression are not expected to result in lower mortality rates at least based on current evidence from observational studies.

Pain and severe sleep disturbance in the general population: Primary data and meta-analysis from 240,820 people across 45 low- and middle-income countries

OBJECTIVE

Pain and sleep disturbances are widespread, and are an important cause of a reduced quality of life. Despite this, there is a paucity of multinational population data assessing the association between pain and sleep problems, particularly among low- and middle-income countries (LMICs). Therefore, we investigated the relationship between pain and severe sleep disturbance across 45 LMICs.

METHOD

Community-based data on 240,820 people recruited via the World Health Survey were analyzed. Multivariable logistic regression analyses adjusted for multiple confounders were performed to quantify the association between pain and severe sleep problems in the last 30 days. A mediation analysis was conducted to explore potential mediators of the relationship between pain and severe sleep disturbance.

RESULTS

The prevalence of mild, moderate, severe, and extreme levels of pain was 26.0%, 16.2%, 9.1%, and 2.2% respectively, whilst 7.8% of adults had severe sleep problems. Compared to those with no pain, the odds ratio (OR, 95% CI) for severe sleep problems was 3.65 (3.24-4.11), 9.35 (8.19-10.67) and 16.84 (13.91-20.39) for those with moderate, severe and extreme pain levels respectively. A country wide meta-analysis adjusted for age and sex demonstrated a significant increased OR across all 45 countries. Anxiety, depression and stress sensitivity explained 12.9%, 3.6%, and 5.2%, respectively, of the relationship between pain and severe sleep disturbances.

CONCLUSION

Pain and sleep problems are highly co-morbid across LMICs. Future research is required to better understand this relationship. Moreover, future interventions are required to prevent and manage the pain and sleep disturbance comorbidity.

Physical Activity and Incident Depression: A Meta-Analysis of Prospective Cohort Studies

OBJECTIVE

The authors examined the prospective relationship between physical activity and incident depression and explored potential moderators.

METHOD

Prospective cohort studies evaluating incident depression were searched from database inception through Oct. 18, 2017, on PubMed, PsycINFO, Embase, and SPORTDiscus. Demographic and clinical data, data on physical activity and depression assessments, and odds ratios, relative risks, and hazard ratios with 95% confidence intervals were extracted. Random-effects meta-analyses were conducted, and the potential sources of heterogeneity were explored. Methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 49 unique prospective studies (N=266,939; median proportion of males across studies, 47%) were followed up for 1,837,794 person-years. Compared with people with low levels of physical activity, those with high levels had lower odds of developing depression (adjusted odds ratio=0.83, 95% CI=0.79, 0.88; I²=0.00). Furthermore, physical activity had a protective effect against the emergence of depression in youths (adjusted odds ratio=0.90, 95% CI=0.83, 0.98), in adults (adjusted odds ratio=0.78, 95% CI=0.70, 0.87), and in elderly persons (adjusted odds ratio=0.79, 95% CI=0.72, 0.86). Protective effects against depression were found across geographical regions, with adjusted odds ratios ranging from 0.65 to 0.84 in Asia, Europe, North America, and Oceania, and against increased incidence of positive screen for depressive symptoms (adjusted odds ratio=0.84, 95% CI=0.79, 0.89) or major depression diagnosis (adjusted odds ratio=0.86, 95% CI=0.75, 0.98). No moderators were identified. Results were consistent for unadjusted odds ratios and for adjusted and unadjusted relative risks/hazard ratios. Overall study quality was moderate to high (Newcastle-Ottawa Scale score, 6.3). Although significant publication bias was found, adjusting for this did not change the magnitude of the associations.

CONCLUSIONS

Available evidence supports the notion that physical activity can confer protection against the emergence of depression regardless of age and geographical region.

Abstract 4256: Handgrip strength and cognitive function in elderly cancer survivors

Aim: Cancer and cancer treatment-related cognitive impairments are frequently reported in cancer survivors, presenting as lack of attention, impaired executive function and short-term money loss. The aetiology of these impairments is largely unknown. Recently, serum level of brain-derived neurotrophic factor (BDNF) has been associated with cancer related cognitive impairments. BDNF is a neurotrophin, secreted in responses to muscle contraction. Meanwhile, muscle dysfunction, characterized by muscle strength and muscle composition, is common in cancer survivors. Yet its impact on cancer survivors' cognitive function is unknown. To address this gap we evaluated for the first time the associations of muscle strength determined by handgrip with two cognitive function outcomes in cancer survivors using data from the National Health and Nutrition Examination Survey (NHANES). Method: Data in two waves of NHANES (2011-2014) were aggregated. Handgrip strength in kilogram (kg) was measured with the Takei Digital Grip Strength Dynamometer, defined as the maximum value achieved using either hand. Data on two cognitive function tests were extracted, both were conducted among adults 60 years and older: the Animal Fluency Test (AFT) which examines categorical verbal fluency (a component of executive function), and the Digital Symbol Substitution test (DSST) which assesses processing speed, sustained attention and working memory. Survey analysis procedures were used to account for the complex sampling design of the NHANES. Gender-specific multivariable linear regression models were used to estimate associations of handgrip strength with cognitive test scores, adjusting for confounders (age, gender, race/ethnicity, education, marital status, smoking status, depression and leisure time physical activity). For explorative purpose, we further adjusted for handgrip strength squared. Results: There were 383 cancer survivors (mean age=70.9 years, mean BMI=29.3 kg/m2) with detailed data for analyses. Prevalent cancer types were breast (22.9%), prostate (16.4%), colon (6.9%) and cervix (6.2%). The prevalence of handgrip strength defined sarcopenia was 10.9% in men (&lt;30kg) and 20.4 % in women (&lt;20kg). Scores on AFT and DSST were 18.0 (s.e. 0.4) and 51.7 (s.e. 1.0), respectively. We observed significant linear associations of handgrip strength with both test scores in women. Each increase kg of handgrip strength was associated with 0.20 (95% CI: 0.08 to 0.33) higher score on AFT and 0.83 (95% CI: 0.30 to 1.35) higher score on DSST. In men, we observed inverted U-shape association between handgrip strength and DSST score, which peaked at handgrip strength of 40-42 kg. Conclusion: Handgrip determined muscle strength appears to be associated with aspects of cognitive functions in cancer survivors. Prospective studies are needed to identify the role of muscle on cancer related-cognitive impairments in men and women cancer survivors.

Citation Format: Lin Yang, Lee Smith, Liang Hu, Graham A. Colditz, Adetunji T. Toriola, Davy Vancampfort, Mark Hamer, Brendon Stubbs, Thomas Waldhör. Handgrip strength and cognitive function in elderly cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4256.

Association Between Muscular Strength and Cognition in People With Major Depression or Bipolar Disorder and Healthy Controls

IMPORTANCE

Objective physical fitness measures, such as handgrip strength, are associated with physical, mental, and cognitive outcomes in the general population. Although people with mental illness experience reduced physical fitness and cognitive impairment, the association between muscular strength and cognition has not been examined to date.

OBJECTIVE

To determine associations between maximal handgrip strength and cognitive performance in people with major depression or bipolar disorder and in healthy controls.

DESIGN, SETTING, AND PARTICIPANTS

In a multicenter, population-based study conducted between February 13, 2005, and October 1, 2010, in the United Kingdom, cross-sectional analysis was conducted of baseline data from 110 067 participants in the UK Biobank. Data analysis was performed between August 3 and August 18, 2017. Invitations were mailed to approximately 9.2 million UK homes, recruiting 502 664 adults, all aged 37 to 73 years. Clinically validated measures were used to identify individuals with major recurrent depression (moderate or severe) or bipolar disorder (type I or type II) and healthy controls (those with no indication of present or previous mood disorders).

MAIN OUTCOMES AND MEASURES

Handgrip dynamometry was used to measure muscular function. Cognitive functioning was assessed using computerized tasks of reaction time, visual memory, number memory, reasoning, and prospective memory. Generalized linear mixed models assessed the association between handgrip strength and cognitive performance, controlling for age, educational level, sex, body weight, and geographic region.

RESULTS

Of the 110 067 participants, analyses included 22 699 individuals with major depression (mean [95% range] age, 55.5 [41-68] years; 7936 [35.0%] men), 1475 with bipolar disorder (age, 54.4 [41-68] years; 748 [50.7%] men), and 85 893 healthy controls (age, 53.7 [41-69] years; 43 000 [50.0%] men). In those with major depression, significant positive associations (P < .001) between maximal handgrip strength and improved performance on all 5 cognitive tasks were found, including visual memory (coefficient, -0.146; SE, 0.014), reaction time (coefficient, -0.036; SE, 0.002), reasoning (coefficient, 0.213; SE, 0.02), number memory (coefficient, 0.160; SE, 0.023), and prospective memory (coefficient, 0.341; SE, 0.024). Similar results were found in healthy controls. Among participants with bipolar disorder, handgrip strength was positively associated with improved visual memory (coefficient, -0.129; SE, 0.052; P = .01), reaction time (coefficient, -0.047; SE, 0.007; P < .001), prospective memory (coefficient, 0.262; SE, 0.088; P = .003), and reasoning (coefficient, 0.354; SE, 0.08; P < .001).

CONCLUSIONS AND RELEVANCE

Grip strength may provide a useful indicator of cognitive impairment in people with major depression and bipolar disorder. Future research should investigate causality, assess the functional implications of handgrip strength in psychiatric populations, and examine how interventions to improve muscular fitness affect neurocognitive status and socio-occupational functioning.

Psychometric properties of the modified Yale Food Addiction Scale 2.0 in a large Brazilian sample

Objective:

The field of food addiction has attracted growing research attention. The modified Yale Food Addiction Scale 2.0 (mYFAS 2.0) is a screening tool based on DSM-5 criteria for substance use disorders. However, there is no validated instrument to assess food addiction.

Methods:

The mYFAS 2.0 has been transculturally adapted to Brazilian Portuguese. The data for this study was obtained through an anonymous web-based research platform: participants provided sociodemographic data and answered Brazilian versions of the the mYFAS 2.0 and the Barratt Impulsivity Scale (BIS-11). Analysis included an assessment of the Brazilian mYFAS 2.0’s internal consistency reliability, factor structure, and convergent validity in relation to BIS-11 scores.

Results:

Overall, 7,639 participants were included (71.3% females; age: 27.2±7.9 years). The Brazilian mYFAS 2.0 had adequate internal consistency reliability (Cronbach’s alpha = 0.89). A single factor solution yielded the best goodness-of-fit parameters for both the continuous and categorical version of the mYFAS 2.0 in confirmatory factor analysis. In addition, mYFAS 2.0 correlated with BIS-11 total scores (Spearman’s rho = 0.26, p < 0.001) and subscores.

Conclusion:

The Brazilian mYFAS 2.0 demonstrated adequate psychometric properties in our sample; however, future studies should further evaluate its discriminant validity.

Grip Strength Is Associated With Cognitive Performance in Schizophrenia and the General Population: A UK Biobank Study of 476559 Participants

Background

Handgrip strength may provide an easily-administered marker of cognitive functional status. However, further population-scale research examining relationships between grip strength and cognitive performance across multiple domains is needed. Additionally, relationships between grip strength and cognitive functioning in people with schizophrenia, who frequently experience cognitive deficits, has yet to be explored.

Methods

Baseline data from the UK Biobank (2007-2010) was analyzed; including 475397 individuals from the general population, and 1162 individuals with schizophrenia. Linear mixed models and generalized linear mixed models were used to assess the relationship between grip strength and 5 cognitive domains (visual memory, reaction time, reasoning, prospective memory, and number memory), controlling for age, gender, bodyweight, education, and geographical region.

Results

In the general population, maximal grip strength was positively and significantly related to visual memory (coefficient [coeff] = -0.1601, standard error [SE] = 0.003), reaction time (coeff = -0.0346, SE = 0.0004), reasoning (coeff = 0.2304, SE = 0.0079), number memory (coeff = 0.1616, SE = 0.0092), and prospective memory (coeff = 0.3486, SE = 0.0092: all P < .001). In the schizophrenia sample, grip strength was strongly related to visual memory (coeff = -0.155, SE = 0.042, P < .001) and reaction time (coeff = -0.049, SE = 0.009, P < .001), while prospective memory approached statistical significance (coeff = 0.233, SE = 0.132, P = .078), and no statistically significant association was found with number memory and reasoning (P > .1).

Conclusions

Grip strength is significantly associated with cognitive functioning in the general population and individuals with schizophrenia, particularly for working memory and processing speed. Future research should establish directionality, examine if grip strength also predicts functional and physical health outcomes in schizophrenia, and determine whether interventions which improve muscular strength impact on cognitive and real-world functioning.

Internet Addiction and Its Relationship With Suicidal Behaviors: A Meta-Analysis of Multinational Observational Studies

OBJECTIVE

To perform a systematic review and meta-analysis of observational studies that investigated the putative association between internet addiction and suicidality.

DATA SOURCES

Major electronic databases (PubMed, Embase, ClinicalKey, Cochrane Library, ProQuest, Science Direct, and ClinicalTrials.gov) were searched using the following keywords (internet addiction OR internet gaming disorder OR internet use disorder OR pathological internet use OR compulsive internet use OR problematic internet use) AND (suicide OR depression) to identify observational studies from inception to October 31, 2017.

STUDY SELECTION

We included 23 cross-sectional studies (n = 270,596) and 2 prospective studies (n = 1,180) that investigated the relationship between suicide and internet addiction.

DATA EXTRACTION

We extracted the rates of suicidal ideation, planning, and attempts in individuals with internet addiction and controls.

RESULTS

The individuals with internet addiction had significantly higher rates of suicidal ideation (odds ratio [OR] = 2.952), planning (OR = 3.172), and attempts (OR = 2.811) and higher severity of suicidal ideation (Hedges g = 0.723). When restricted to adjusted ORs for demographic data and depression, the odds of suicidal ideation and attempts were still significantly higher in the individuals with internet addiction (ideation: pooled adjusted OR = 1.490; attempts: pooled adjusted OR = 1.559). In subgroup analysis, there was a significantly higher prevalence rate of suicidal ideation in children (age less than 18 years) than in adults (OR = 3.771 and OR = 1.955, respectively).

CONCLUSIONS

This meta-analysis provides evidence that internet addiction is associated with increased suicidality even after adjusting for potential confounding variables including depression. However, the evidence was derived mostly from cross-sectional studies. Future prospective studies are necessary to confirm these findings.

Hand grip strength and cognitive function among elderly cancer survivors

Background

We evaluated the associations of handgrip strength and cognitive function in cancer survivors ≥ 60 years old using data from the National Health and Nutrition Examination Survey (NHANES).

Methods

Data in two waves of NHANES (2011–2014) were aggregated. Handgrip strength in kilogram (kg) was defined as the maximum value achieved using either hand. Two cognitive function tests were conducted among adults 60 years and older. The Animal Fluency Test (AFT) examines categorical verbal fluency (a component of executive function), and the Digital Symbol Substitution test (DSST) assesses processing speed, sustained attention, and working memory. Survey analysis procedures were used to account for the complex sampling design of the NHANES. Multiple linear regression models were used to estimate associations of handgrip strength with cognitive test scores, adjusting for confounders (age, gender, race/ethnicity, education, marital status, smoking status, depressive symptoms and leisure time physical activity).

Results

Among 383 cancer survivors (58.5% women, mean age = 70.9 years, mean BMI = 29.3 kg/m²), prevalent cancer types were breast (22.9%), prostate (16.4%), colon (6.9%) and cervix (6.2%). In women, each increase in kg of handgrip strength was associated with 0.20 (95% CI: 0.08 to 0.33) higher score on AFT and 0.83 (95% CI: 0.30 to 1.35) higher score on DSST. In men, we observed an inverted U-shape association where cognitive function peaked at handgrip strength of 40–42 kg.

Conclusions

Handgrip strength, a modifiable factor, appears to be associated with aspects of cognitive functions in cancer survivors. Prospective studies are needed to address their causal relationship.

Leisure time physical activity and future psychological distress: A thirteen year longitudinal population-based study

A number of cross-sectional studies have suggested that physical activity (PA) is negatively associated with psychological distress in adulthood. A paucity of regionally representative and longitudinal studies has considered this relationship. This study investigated the association between leisure time light and moderate-vigorous PA (MVPA) and psychological distress over 13 years in a regionally representative sample. A total of 4754 men (mean age: 47.2 years) and 5571 women from (mean age: 46.9 years) the Tromsø Study were followed for 13 years. Light PA and MVPA was captured at baseline and psychological distress was captured using the Hopkins Symptom Check List-10 scale. Ordinary least square and Poisson regression models were used, adjusting for multiple confounders to investigate the relationship between light PA/MVPA and psychological distress. In the fully-adjusted model, accounting sociodemographics, history of parental psychopathology, socioeconomic status, marital status, smoking, social support and risk factors, we found evidence that both light PA (β 0.11, 95% CI: 0.03, 0.19; p < 0.01) and MVPA (β 0.19, 95% CI: 0.12, 0.26; p < 0.001) confered protection against psychological distress at follow-up. Among men, a lower MVPA was associated with 14% (RR = 1.14, 95% CI: 1.01, 1.28) increased risk of clinically significant psychological distress; while among women, the risk was 15% (RR = 1.15, 95% CI: 1.06, 1.26; p < 0.001). In this regionally representative cohort, our study suggests that both higher levels of light PA and MVPA confer protection against future psychological distress. However, a key limitation of this study is that psychological distress at baseline was not controlled-for.