Chapter 9: The relationship between physical activity and anxiety and depression Can physical activity beat the blues an

1. Chapter 9:The relationship between physical activity and anxiety and depressionCan physical activity beat the blues and help with your nerves?

2. Buckworth and Dishman (2002) pointed out that as long ago as 1899 William James said that “our muscular vigor will … always be needed to furnish the background of sanity, and cheerfulness to life, to give moral elasticity to our dispositions, to round off the wiry edge of our fretfulness, and make us good-humoured” Maybe now we are ready to listen to this message!

3. Chapter 9: Aims • define anxiety and depression for clinical and non-clinical populations • introduce and define the topic of mental illness • discuss the evidence base and mention the problems of cross-sectional data • review and summarise the evidence linking exercise with non-clinical states of anxiety • summarise the evidence about exercise and clinical anxiety disorders • review and summarise the findings about exercise and non-clinical depression • provide a review of the literature on physical activity and exercise on and clinical depression • provide a critique of whether or not the evidence shows a causal relationship between exercise and depression

4. Mental health is a public health issue • Mental illness is not a trivial issue affecting small proportions of the population. • In some countries it is as common as high blood pressure and is therefore a major public health concern. • WHO has predicted that depression will create the greatest burden of disease by 2020

5. Increases in anti-depressant drug prescriptions in England 1991-2003

6. Relationship between physical activity and depression assessed with the CES-D

7. Summary of DSM -IV criteria for major depressive episode

8. Prevalence • Depression is one of the most common psychiatric problems. • An estimated 20% of consultees in primary care have some degree of depressive symptomology.

9. Treatment • drugs are the most common treatment in the UK • not all patients want drugs • counselling is effective but time consuming • cognitive-behavioural therapy also effective but in scarce supply • ECT is used in UK • recovery is normally expected

10. 1965 activity level and 1974 depression (reporting 5 or more symptoms from 18 symptom list) Camacho et al (1991) American J Epidemiology, 134, 220-231 Activity level calculated from frequency intensity reports of leisure activities producing a 14 point scale that predicted mortality and morbidity for this sample. Low = 0-4 points; moderate =5-8; high = 9-14.

11. BDI scores pre and post 16 weeks of treatment (from Blumenthal et al, 1999) and 6 month follow up (Babyak et al, 2000)

12. Dunn, A., Trivedi, M. H., Kampert, J., Clark, C. G., & Chambliss, H. O. (2005). Exercise treatment for depression. Efficacy and dose-response. American Journal of Preventive Medicine, 28(1), 1-8. The public health dose of exercise was more effective in reducing depression scores to a clinically acceptable level than the lower dose or the control condition. Frequency of exercise (3 or 5 days/week) was not important.

13. Conclusions - clinical anxiety disorders • Very little is known about how exercise effects clinical anxiety disorders in comparison to what is known about depression. • This may partly be due to the number of diagnoses at the clinical level which could include symptoms of anxiety (eg phobias, mixed anxiety depression diagnosis) • there is a potential association between exercise and reduction in anxiety symptoms.

14. Key point: • There is a range of levels of anxiety and depression that might be classed as normal at one level and clinical at another. Clear definitions exist for the clinical end of this spectrum.

15. Key point: • Mental health is a public health concern and physical activity may assist in prevention and treatment.

16. Key point: • Exercise has a small to moderate effect on reducing non-clinical levels of anxiety.

17. Key point: • There is too little evidence to make firm conclusions about the role of exercise in the prevention or treatment of anxiety disorders.

18. Key point: • It may be that many people who have mild to moderate depression, or even sub-clinical levels of depression, could benefit from increased activity.

19. Key point: • Higher levels of physical activity are consistently related to lower levels of depression in population surveys. The question remains about which comes first. This may be more easy to answer about depression than it was about anxiety.

20. Key point: • The weight of evidence from prospective population surveys suggests that physical activity has a protective effect in terms of clinical levels of depression.

21. Chapter 9: Conclusions 1 • meta-analytic findings suggest that exercise is associated with a significant small-to-moderate reduction in non-clinical anxiety • experimental studies support an anxiety-reducing effect for non-clinical anxiety • large-scale epidemiological surveys offer mixed support for anxiety-reducing effects for exercise but there are few surveys that have anxiety data • physiological reactivity to psychosocial stressors appears to be reduced for those high in aerobic fitness • very little is known about how physical activity and exercise relate to clinical anxiety conditions at a population level • experimental studies are not yet convincing enough to suggest a causal link between activity and reduction of clinical anxiety • there is no evidence that exercise might induce panic or anxiety in participants with anxiety disorders.

22. Chapter 9: Conclusions 2 • meta-analytic findings suggest that exercise is associated with a significant moderate reduction in non-clinical depression. • large-scale epidemiological surveys support the claim that a physically active lifestyle is associated with lower levels of non-clinical depression. • the weight of evidence shows that prospective studies suggest a protective effect from activity on the development of clinical levels of depression • meta-analytic findings show a large effect size from studies that have used exercise as a treatment for clinically defined depression • the weight of the evidence suggests that there is a causal connection between physical activity/exercise and depression