Cillian P. McDowell

Association of Efficacy of Resistance Exercise Training With Depressive Symptoms: Meta-analysis and Meta-regression Analysis of Randomized Clinical Trials

Importance The physical benefits of resistance exercise training (RET) are well documented, but less is known regarding the association of RET with mental health outcomes. To date, no quantitative synthesis of the antidepressant effects of RET has been conducted. Objectives To estimate the association of efficacy of RET with depressive symptoms and determine the extent to which logical, theoretical, and/or prior empirical variables are associated with depressive symptoms and whether the association of efficacy of RET with depressive symptoms accounts for variability in the overall effect size. Data Sources Articles published before August 2017, located using Google Scholar, MEDLINE, PsycINFO, PubMed, and Web of Science. Study Selection Randomized clinical trials included randomization to RET (n = 947) or a nonactive control condition (n = 930). Data Extraction and Synthesis Hedges d effect sizes were computed and random-effects models were used for all analyses. Meta-regression was conducted to quantify the potential moderating influence of participant and trial characteristics. Main Outcomes and Measures Randomized clinical trials used validated measures of depressive symptoms assessed at baseline and midintervention and/or postintervention. Four primary moderators were selected a priori to provide focused research hypotheses about variation in effect size: total volume of prescribed RET, whether participants were healthy or physically or mentally ill, whether or not allocation and/or assessment were blinded, and whether or not the RET intervention resulted in a significant improvement in strength. Results Fifty-four effects were derived from 33 randomized clinical trials involving 1877 participants. Resistance exercise training was associated with a significant reduction in depressive symptoms with a moderate-sized mean effect [INCREMENT] of 0.66 (95% CI, 0.48-0.83; z = 7.35; P < .001). Significant heterogeneity was indicated (total Q = 216.92, df = 53; P < .001; I2 = 76.0% [95% CI, 72.7%-79.0%]), and sampling error accounted for 32.9% of observed variance. The number needed to treat was 4. Total volume of prescribed RET, participant health status, and strength improvements were not significantly associated with the antidepressant effect of RET. However, smaller reductions in depressive symptoms were derived from randomized clinical trials with blinded allocation and/or assessment. Conclusions and Relevance Resistance exercise training significantly reduced depressive symptoms among adults regardless of health status, total prescribed volume of RET, or significant improvements in strength. Better-quality randomized clinical trials blinding both allocation and assessment and comparing RET with other empirically supported treatments for depressive symptoms are needed.

Sex-related differences in the association between grip strength and depression: Results from the Irish Longitudinal Study on Ageing

Abstract Muscular strength is a modifiable protective factor for mental health across aging populations. Evidence of sex‐related differences in its associations with mental health is limited. Therefore, the purpose of this study was to examine sex‐related differences in cross‐sectional and prospective associations between grip strength and depressive symptoms and status. Participants were community dwelling adults (N = 4505; 56.5% female), aged ≥50 years. As a measure of muscular strength, grip strength (kg) of the dominant hand was assessed using a hand‐held dynamometer at baseline. Participants were divided into sex‐specific tertiles. The Center for Epidemiological Studies Depression Scale assessed depressive symptoms at baseline and two years later; a score of ≥16 defined caseness of depression. Depressive symptoms were significantly higher among females at baseline (p < 0.001). Prospective models were adjusted for age, sex, waist circumference, social class, smoking, and health status. Among males, the middle and high strength tertiles were non‐significantly associated with 32.9% (p = 0.21) and 9.9% (p = 0.74) reduced odds of developing depression, respectively. Among females, the middle and high strength tertiles were non‐significantly associated with 28.5% (p = 0.13) and significantly associated with 43.4% (p = 0.01) reduced odds of developing depression, respectively. In the total sample, the middle and high strength tertiles were significantly associated with 31.5% (p = 0.04) and 34.1% (p = 0.02) reduced odds of developing depression, respectively. The interaction between sex and strength was not statistically significant (p = 0.25). The present findings indicated that grip strength was inversely associated with incident depression in older adults, with stronger associations observed among females than males. HighlightsGrip strength was inversely associated with prevalent and incident depressionStronger prospective associations were observed among females than malesSmokers, respondents diagnosed with an illness, and those aged 70‐79 and 80+ years were most likely to report lowest strength

The Effects of Exercise Training on Anxiety in Fibromyalgia Patients: A Meta-analysis

Physical inactivity and comorbid anxiety symptoms are prevalent among fibromyalgia (FM) patients. Exercise training may be an effective alternative therapy to reduce these symptoms. Purpose This study aimed to evaluate the effects of exercise training on anxiety symptoms in patients with FM and to examine whether variables of theoretical or practical importance moderate the estimated mean effect. Methods Twenty-five effects were derived from 10 articles published before June 2016 located using Google Scholar, MEDLINE, PsycINFO, PubMed, and Web of Science. Trials involved 595 patients with FM (mean age = 47.6 yr, 97.5% female) and included both randomization to exercise training (n = 297) or a nonexercise control condition (n = 298) and an anxiety outcome measured at baseline and during and/or after exercise training. Hedges’ d effect sizes were computed, data for moderator variables were extracted, and random effects models were used to estimate sampling error and population variance for all analyses. Meta-regression quantified the extent to which patient and trial characteristics moderated the mean effect. Results Exercise training significantly reduced anxiety symptoms by a mean effect &Dgr; of 0.28 (95% confidence interval [CI] = 0.16–0.40). No significant heterogeneity was observed (Q24 = 30.79, P = 0.16, I2 = 25.29%). Program duration (&bgr; = 1.44, z = 2.50, P ⩽ 0.01) was significantly related to the overall effect, with significantly larger anxiety improvements resulting from programs lasting greater than 26 wk (&Dgr; = 0.35, 95% CI = 0.05–0.66) compared with those lasting less than 26 wk (&Dgr; = 0.26, 95% CI = 0.13–0.39). Conclusion Exercise training improves anxiety symptoms among FM patients. The findings also suggest that larger anxiety symptom reductions will be achieved by focusing on longer exercise programs while promoting long-term adherence. Future well-designed investigations are required to examine the potential moderating effect of pain-related improvements in FM patients.

Associations of physical activity and depression: Results from the Irish Longitudinal Study on Ageing

ABSTRACT Physical activity (PA) can protect against depression, but few studies have assessed whether meeting PA guidelines is sufficient, or if benefits can be derived from greater volumes of PA. The present study examines cross‐sectional and prospective associations between different volumes of moderate‐to‐vigorous PA (MVPA) and walking, and depressive symptoms and status. Participants (n=4556; 56.7% female) aged≥50years completed the International PA Questionnaire (IPAQ) at baseline and the Center for Epidemiological Studies Depression Scale at baseline and two years later. Prevalence and incidence of depression were 9.0% (n=410) and 5.0% (n=207), respectively. After full adjustment, odds of prevalent depression were: 40% (OR=0.60, 95%CI: 0.48–0.76) lower among those meeting PA guidelines; 23% (OR=0.77, 0.49–1.21) and 43% (OR=0.57, 0.45–0.73) lower among those in moderate and high categories, respectively; and, 22% (OR=0.78, 0.61–1.01) and 44.0% (OR=0.56, 0.42–0.74) lower among those in moderate and high walking tertiles, respectively. Odds of incident depression were: 23% (OR=0.77, 0.58–1.04) lower among those meeting PA guidelines; 37% (OR=0.63, 0.32–1.22) and 20.0% (OR=0.80, 0.59–1.09) lower among those in moderate and high categories, respectively; and, 21% (OR=0.79, 0.56–1.12) and 25% (OR=0.75, 0.52–1.07) lower among those in moderate and high walking tertiles, respectively. Moderate and high volumes of MVPA were significantly associated with lower odds of concurrent depression, and significantly and non‐significantly associated with reduced odds of incident depression, respectively. Meeting recommended levels of MVPA and walking were associated with significantly lower odds of concurrent depression, and non‐significantly reduced odds of the development of depression over two years. HIGHLIGHTSA greater proportion of respondents who reported depression were aged 80+ years, female, and current smokers.A dose‐response was observed for moderate‐to‐vigorous physical activity (PA) and walking in cross‐sectional analyses.Meeting PA guidelines was significantly and non‐significantly associated with lower odds of prevalent and incident depression.