Exercise, a treatment for depression
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Exampleessay_mark891.pdf
MSc Physical Activity for Health
Assignment Submission Sheet
Course Title
Psychology of Physical Activity
Exam Number
B125502
Submission Date
11.12.2017
Assignment Title
Exercise as treatment for mild or moderate depression
Action on prior feedback (optional but recommended):
The understanding should not be compromised by shortening sentences
Elaborate on major points of thought
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Inhalt Tables ...................................................................................................................................................... 3
Figures ..................................................................................................................................................... 3
Abbreviations .......................................................................................................................................... 3
1. Introduction ..................................................................................................................................... 4
2. Depression ....................................................................................................................................... 4
3. Physical activity as treatment of depression .................................................................................... 5
a. Evidence ................................................................................................................................... 5
b. Critique .................................................................................................................................... 7
4. Possible underlying mechanisms ..................................................................................................... 7
5. Current Guidelines ........................................................................................................................... 9
6. Conclusion ....................................................................................................................................... 9
Appendix ............................................................................................................................................... 11
References ............................................................................................................................................. 12
Tables Table 1. Summary of possible underlying mechanisms, mediating the influence of exercise on
depressive symptoms ............................................................................................................... 8
Table 2 Summary of published guidelines for exercise as treatment for mild or moderate depression .. 9
Figures Figure 1. Summary of the symptoms for depression according to the DSM-5 (American Psychiatric
Association, 2013; Biddle et al., 2015, p. 70). ............................................................................ 4
Figure 2. Screenshot of the animated video “Be active, be happy!” to promote exercise as physical
activity to patients suffering from mild or moderate depression.
(https://www.youtube.com/watch?v=e7dygep2hcc). ............................................................... 11
Abbreviations BDI – Becks Depression Inventory
LD – low dose
NICE – National Institute for Health Care and Excellence
PHD – public health dose
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1. Introduction Depression is a common disorder, affecting 300 million people worldwide and it has been shown to be
a leading cause of ill health and disabilities (Cooney et al., 2013; World Health Organization, 2017).
Precisely, Mathers and Loncar (2006) estimate that depression will be the most influential risk factor
for disabled life in 2030. The treatment of depression is important as this disorder also has a negative
impact on organs increasing the risk for chronic health issues such as cardiovascular diseases (Carney,
Freedland, Miller, & Jaffe, 2002). Yet, no single treatment has been found to be effective for all
patients suffering from depression, hence alternative approaches need to be considered (Blumenthal et
al., 2007; Cooney et al., 2013). As relatively new approach, exercise was included in the official
guidelines of 2009 to treat mild and moderate depressions (National Institute for Health and Clinical
Excellence, 2009). However, many still question the efficacy of this approach (Stathopoulou, Powers,
Berry, Smits, & Otto, 2006).
This essay will focus on physical activity as a treatment for depression, while first describing
the affective disorder in the following chapter. Subsequently, different studies investigating the effects
of exercise on depressive symptoms will be presented and critique of the evidence provided. Possible
underlying mechanisms will be explained, and current guidelines summarized.
2. Depression The affective disorder of depression is characterized by a loss of positive affect (Robertson,
Robertson, Jepson, & Maxwell, 2012). It lies on the extreme end of a continuum of negative mood
ranging from unhappiness to long-lasting low mood and the inability to enjoy anything, resulting at its
most extreme in a suicide attempt (Biddle, Mutrie, & Gorely, 2015). The symptoms according to the
DSM-5 (American Psychiatric Association, 2013) are summarized in figure 1.
Figure 1. Summary of the symptoms for depression according to the DSM-5 (American Psychiatric
Association, 2013; Biddle et al., 2015, p. 70).
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Depression affects 4-10% of individuals, while the estimate lies at 7% in the United Kingdom, of
which 75% are treated in primary care, usually receiving psychopharmacological pills or
psychotherapy (Cooney et al., 2013; Robertson et al., 2012). Dunn et al. (2005) estimate that only 23%
of patients seek help and only 10% receive adequate treatment. The low number of those seeking
treatment might be explained by the high stigma associated with mental health issues (Dunn et al.,
2005). Exercise, however, is not stigmatized, which might convince more patients to seek help.
3. Physical activity as treatment of depression Chronic physical activity has been shown to have a positive effect on overall mood (Bernstein &
McNally, 2016). More importantly, it is also associated with a reduction in depressive symptoms in
various subgroups (e.g. De Mello et al., 2013; Lee et al., 2012; Physical Activity Guidelines Advisory
Committee, 2008; Stanton & Reaburn, 2014). Findings from randomized controlled trials, systematic
reviews and meta-analyses suggest that physical exercise is furthermore as effective as medication and
psychotherapeutic treatment (Blumenthal et al., 2007; Cooney et al., 2013; Dunn et al., 2005; Rimer et
al., 2012; Stanton & Reaburn, 2014).
a. Evidence Fremont (1987) was one of the first researchers to investigate exercise as treatment. He compared pre-
and post-intervention scores of 61 patients with a mild or moderate depression diagnosis who received
either verbal (cognitive) therapy or aerobic exercise as treatment. He found significant decreases in
Becks Depression Inventory (BDI) scores in all conditions and the effect sizes were equal for either
diagnosis severity and intervention condition.
Stathopoulou et al. (2006) conducted a meta-analysis in which they included 11 treatment studies
comparing exercise to inactive comparison groups. They found a very large effect size (g = 1.39),
however only recommended exercise as a conjunctive treatment. More optimistic were Blumenthal et
al. (2007) with the results of their methodologically rigorous study, which included 202 adults
diagnosed with mild or moderate depression randomly assigned to one of four groups: home-based
exercise intervention, supervised exercise intervention, pharmacological treatment, and placebo-pill
group. The results implicate that up to 45% remitted (BDI < 7) in the supervised exercise group,
compared to 47% in the pharmacological one. The overall efficacy was comparable between all active
conditions. In addition, there was no interaction effect of diagnosis severity. A newer systematic
review in the Cochrane Library by Rimer et al. (2012) including 30 studies only found a medium
effect size of -0.67. However, they only included studies comparing exercise conditions to no
treatment. Cooney et al. (2013) updated this systematic review by including studies comparing
exercise conditions and medication, in which they again found no significant difference. Nonetheless,
they concluded that exercise does not appear to be more effective than psychological or
pharmacological treatment. This, however, is only based on 4 trials.
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The above cited studies often focused on physical activity in general, without differentiating between
the intensity or frequency of exercise sessions. However, understanding these factors is of interest for
practical implications. Dunn et al. (2005) therefore compared different intensities (17.5-kcal/kg/week
vs. 7.0-kcal/kg/week) and frequencies (3 vs. 5 times per week) of exercise. All exercise sessions were
applied in an individual setting to control for possible effects due to perceived social support. The
public health dose (PHD) described the higher exercise intensity, while the other condition was
labelled low dose (LD). The findings showed PHD to be more effective than LD to treat mild or
moderate depression. Meanwhile, LD did not significantly differ from the control group. Dunn et al.
(2005) concluded that exercise used for treatment should be at the intensity of the recommended
public health guidelines of 150 minutes of moderate-to-vigorous physical activity a week (World
Health Organization, 2010). Additionally, there was no significant difference in symptom reduction
between the two frequencies in this prospective study (Dunn et al., 2005). The adherence and dropout
rate were however lower in the group with less frequent sessions. In line are the findings of Stanton
and Raeburn’s review of 5 studies (2014) as they found higher adherence rates in lower dose
conditions, which might be due to less adverse effects.
In 2008, the Physical Activity Guidelines Advisory Committee also declared that low intensity
physical activity is not as effective as higher intensity. Robertson et al. (2012) investigated this further
by conducting a meta-analysis examining walking trials (8 studies). Controversially to prior findings,
they found a large effect size (ES = - 0.86), that was equivalent to those shown in meta-analyses and
systematic reviews not restricted to walking (Stathopoulou et al., 2006). These findings are of special
importance as walking can be undertaken by almost everyone, is very low cost-effective, and can be
implemented in everyday life, with minimal adverse risks known (Robertson et al., 2012).
Additionally, there are already various campaigns to encourage walking in order to break the habit of
sedentary behavior (e.g. Paths for All, Stepcount; Paths for all, 2014, 2017).
Other factors of interest are types of exercise, locations, and group or individual settings as
possible moderators. Most of the conducted studies used aerobic exercises as intervention
(Stathopoulou et al., 2006). Martinsen et al. (1989) though compared anaerobic and aerobic exercise
and found no difference in depression scores during post-measurement. This suggests that there is an
opportunity to adjust exercise programs to the patients’ needs and wishes (Stathopoulou et al., 2006).
Comparing group or individual interventions, the results were mixed (Perraton et al., 2010; Stanton &
Reaburn, 2014); it seems reasonable however to argue for group settings, as patients suffering from
depression often lack social contact (Blumenthal et al., 2007; Wittchen & Hoyer, 2011). Similar,
Blumenthal et al. (2007) found no differences in post-intervention depression scores between home-
based and supervised exercise. However, it became evident that supervised participants pushed
themselves further, while it is not of importance how professional this supervision is (Perraton et al.,
2010). Overall, the decreasing effect of exercise on depression was shown for interventions conducted
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at various locations (Perraton et al., 2010), while outdoor walking might additionally reduce stress
levels due to the experience of the natural environment (Robertson et al., 2012).
b. Critique The results are promising; however, the studies have limitations, thus decreasing the validity of the
findings. As Perraton et al. (2010) point out, most studies lack blinding procedure, intention-to-treat
analyses and show poor concealment of allocation. Furthermore, they often reached only a small
sample size, follow-ups were not included in the designs, and the generalizability to all severities of
depression was compromised (Blumenthal et al., 2007; Robertson et al., 2012; Stanton & Reaburn,
2014). The latter is due to the fact that the trials include mild to moderately affected patients based on
ethical aspects and participation on a voluntary basis (Blumenthal et al., 2007). Nonetheless,
improvement can be seen over the past years, as placebo conditions and intention-to-treat analysis
have become more commonly included in order to prove the efficacy of the treatment (Blumenthal et
al., 2007; Perraton et al., 2010).
Another limitation are biases such as the publication bias (Cooney et al., 2013; Rimer et al., 2012).
The meta-analysis of Stathopoulous et al. (2006) is a good examples as it only includes trials with
significant effects. Also surprising is that many of the authors do not represent their findings
optimistically by recommending exercise solely as an adjunctive therapy (Bernstein & McNally, 2016;
Lawlor & Hopker, 2001; Stanton & Reaburn, 2014; Stathopoulou et al., 2006). Rimer et al. (2012)
were more positive in this way and in line with Biddle et al. (2015), who promote the “glass half-full
perspective” as the effect sizes were large in many studies, favoring exercise as treatment. This should
be noted especially since the relevant studies were conducted in different populations, samples,
circumstances, and time periods, raising the external validity.
4. Possible underlying mechanisms Evidence for the beneficial effects of exercise in the treatment of depression, including its critique, has
been shown in the previous chapters. However, there is still little known about the underlying
mechanisms explaining this association (Bernstein & McNally, 2016; Blumenthal et al., 2007;
Physical Activity Guidelines Advisory Committee, 2008). Numerous different mechanisms have been
proposed, including biochemical, physiological, psychological, and psychosocial processes (Robertson
et al., 2012). Stathopoulou et al. (2006) classified the assumed processes into psysiological and
phychological mechanisms, summarized in table 1. Only a few of those will be described in the
following section.
In their study of emotion regulation, Bernstein and MacNally (2016) focused on the psychological
processes, hypothesizing that exercise strengthens coping strategies for emotional stressors and
suggesting exercise as a booster for self-efficacy. Indeed, their results showed better emotional coping
skills after emotion-inducing movie sequences following exercise. Similar results were found by
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Stathopoulou et al (2006) as exercising women scored higher in coping self-efficacy and lower in
depression scores than the sedentary control group. Furthermore, this self-related psychological
construct is assumed to be higher due to an increase in mood after physical activity (Cooney et al.,
2013). It is also associated with self-esteem and proposed to be one of the strongest predictors of well-
being showing an inverse relationship (Diener, 1984). Another factor related to coping strategies is the
experience of mastery, which can be induced by exercise (Stathopoulou et al., 2006).
Table 1.
Summary of possible underlying mechanisms, mediating the influence of exercise on depressive
symptoms.
Psychological changes Physiological changes
underlying
mechanisms
increase in self-efficacy
sense of mastery
positive thoughts
distraction from negative
thoughts
enhanced self-concept
increased stress-coping
strategies
change in action tendencies
increased norepinephrine neurotransmission
alterations in the hypothalamo-pituitry-
adrenocortical axis
increased secretion of amine metabolites
increased serotonin synthesis and metabolism
increased brain-derived neuro factors *
increase in β-endorphins *
increase of vascular endothelial growth factors
*
increased serotonin levels *
* = mechanisms proposed by Ernst et al (2006) to increase neurogenesis
The psychotherapeutic perspective considers a modification of action tendency (Stathopoulou et al.,
2006). Depression is bound to passivity, with action tendencies of inactivity and withdrawal, which
can be understood as maladaptive coping strategies. Exercise, however, requires actions from the
individual and might change behavioral tendencies. The positive benefits may be enhanced by social
contact during exercise (Cooney et al., 2013).
Turning to the physiological mechanisms, neurogenesis and changes in the endocrine system
are of importance. Antidepressants augment the synthesis of cerebral neurogenesis, an impaired
process seen as partly responsible for depressions in adults (Rethorst, Wipfli, & Landers, 2009).
Increases in neurogenesis have been shown after exercise in cerebral areas (Ernst et al., 2006;
Wittchen & Hoyer, 2011). Additionally, Ernst et al. (2006) proposed four detailed mechanisms that
increase neurogenesis (table 1) including increased serotonin level after exercising. This hypothesis is
supported by Broocks et al. (2003). Low levels in serotonin are supposed to be an alternative cause for
depression as antidepressants work by inhibiting the serotonin reuptake and the disrupted sleep cycle
in depressed patients is partly attributed to low levels of serotonin (Hamm, 2016).
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The mechanisms are extensive and not yet fully understood. One can understand that many are still
skeptical about exercise as treatment due to the unknown mechanisms and lack of methodological
rigor. Yet, it can be compared to electro convulsion therapy: a treatment not yet grasped in its
mechanisms, but still advocated (Biddle et al., 2015).
5. Current Guidelines Despite the critique of the studies presented, exercise is rightfully included in guidelines as treatment
for mild or moderate depressions by several institutions (Biddle et al., 2015), while antidepressants are
not recommended for mild depression (Robertson et al., 2012). The National Health Service (2016),
the Royal College of Psychiatrists (2012) and the Scottish Association for Mental Health (2017)
recommend exercising on their website to help with depressions and suggest it as one of the main
treatments for mild depression. Further explicit guidelines are summarized in table 2.
The National Institute for Health and Care Excellence (NICE; 2009) includes structured and
supervised exercise programs in their official treatment guidelines. Exercise interventions should
contain 3 sessions a week of 45 to 60 minutes over a period of at least 10-14 weeks. Stanton and
Raeburn (2014) summarized recommendations similar to those published by NICE: slightly less
intense, including 30 to 40 minute sessions of low to moderate intensity. In line with this, Dunn et al.
(2005) concluded that exercise used for treatment should be at the intensity of the recommended
public health guidelines. Perraton et al. (2010) inferred their guidelines solely based on the
interventions most commonly used in the studies included in their meta-analysis. These are lower than
the NICE guidelines or the public health guidelines for physical activity.
Table 2
Summary of published guidelines for exercise as treatment for mild or moderate depression.
NICE (2009) Perration et al. (2010) Stanton & Raeburn (2014)
Sessions per week
Minutes per session
Duration in weeks
3
40 - 60
10 - 14
3
30
> 8
3-4
30 - 40
> 9
However, overall these recommendations do not differ much from the general recommendation and
one could ask whether different guidelines for patients with depression are needed at all (Stanton &
Reaburn, 2014) Instead, it should be considered to prescribe exercise programs for everyone suffering
from depression (Stanton & Reaburn, 2014).
6. Conclusion From the prior chapters it can be concluded that exercise is effective, yet there is still a lack of
evidence, which should be addressed in future research, especially focusing on efficacy studies.
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However, there is hitherto no evidence of negative effects of exercise for depression (Biddle et al.,
2015), which is far more than can be said of antidepressant medication (Rethorst et al., 2009).
Furthermore, physical activity is not only beneficial for the decrease of depressive symptoms but has a
variety of other positive health outcomes (further reading in Lee et al., 2012).
It is necessary to advocate the option of exercise as treatment to those who suffer from depression and
to health care professionals, as it cannot only treat, but also prevent depressive disorders (Biddle,
Mutrie, & Gorely, 2015). Based on this essay, a video resource was developed to educate patients
about exercise as treatment approach for mild or moderate depression (figure 2 in appendix).
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Appendix
Figure 2. Screenshot of the animated video “Be active, be happy!” to promote exercise as physical
activity to patients suffering from mild or moderate depression.
(https://www.youtube.com/watch?v=e7dygep2hcc)
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References American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders:
DSM-5. American Psychiatric Association (5th ed.). Arlington, VA.: American Psychiatric
Association.
Bernstein, E. E., & McNally, R. J. (2016). Acute aerobic exercise helps overcome emotion regulation
deficits. Cognition and Emotion, 31(4), 834–843.
Biddle, S., Mutrie, N., & Gorely, T. (2015). Physical activity and clinical depression - Can physical
activity beat the blues ? In Psychology of Physical Activity: Determinants, Well-Being and
Interventions (pp. 68–95). London: Routledge: Tayloer and francis.
Blumenthal, J. A., Babyak, M. A., Doraiswamy, P. M., Watkins, L., Hoffman, B. M., Barbour, K. A.,
… Sherwood, A. (2007). Exercise and Pharmacotherapy in the Treatment of Major Depressive
Disorder. Psychosomatic Medicine, 69(7), 587–596.
Broocks, A., Meyer, T., & Opitz, M. (2003). 5-HT 1A responsivity in patients with panic disorder
before and after treatment with aerobic exercise, clomipramine or placebo. European …, 13,
153–164.
Carney, R. M., Freedland, K. E., Miller, G. E., & Jaffe, A. S. (2002). Depression as a risk factor for
cardiac mortality and morbidity: A review of potential mechanisms. Journal of Psychosomatic
Research, 53(4), 897–902.
Cooney, G., Dwan, K., Greig, C., Lawlor, D., Rimer, J., Waugh, F., … Mead, G. (2013). Exercise for
depression (Review). Cochrane Database of Systematic Reviews, (9), 1–160.
De Mello, M. T., Lemos, V. D. A., Antunes, H. K. M., Bittencourt, L., Santos-Silva, R., & Tufik, S.
(2013). Relationship between physical activity and depression and anxiety symptoms: A
population study. Journal of Affective Disorders, 149(1–3), 241–246.
Diener, E. (1984). Subjective well-being. Psychological Bulletin, 95(3), 542–575.
Dunn, A. L., Trivedi, M. H., Kampert, J. B., Clark, C. G., & Chambliss, H. O. (2005). Exercise
treatment for depression: Efficacy and dose response. American Journal of Preventive Medicine,
28(1), 1–8.
Ernst, C., Olson, A. K., Pinel, J. P. J., Lam, R. W., & Christie, B. R. (2006). Antidepressant effects of
exercise: Evidence for an adult-neurogenesis hypothesis? Journal of Psychiatry and
Neuroscience, 31(2), 84–92.
Fremont, J., & Craighead, L. W. (1987). Aerobic exercise and cognitive therapy in the treatment of
dysphoric moods. Cognitive Therapy and Research, 11(2), 241–251.
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13
Hamm, A. (2016). Depression [powerpoint slides]. Retrieved November 8, 2016, from https://moodle-
web.uni-greifswald.de/moodle/user/profile.php?id=481
Lawlor, D. A., & Hopker, S. W. (2001). The effectiveness of exercise as an intervention in the
management of depression: systematic review and meta-regression analysis of randomised
controlled trials. BMJ (Clinical Research Ed.), 322(7289), 763–772.
Lee, I. M., Shiroma, E. J., Lobelo, F., Puska, P., Blair, S. N., & Katzmarzyk, P. T. (2012). Effect of
physical inactivity on major non-communicable diseases worldwide: An analysis of burden of
disease and life expectancy. The Lancet, 380(9838), 219–229.
Martinsen, E. W., Hoffart, A., Solberg, Ø., & Solberg, F. (1989). Comparing aerobic with nonaerobic
forms of exercise in the treatment of clinical depression: A randomized trial. Comprehensive
Psychiatry, 30(4), 324–331.
Mathers, C., & Loncar, D. (2006). Projections of global mortality and burden of disease from 2002 to
2030. PLoS Medicine, 3(11), 2011–2030.
National Health Service. (2016). Clinical Depression. Retrieved December 8, 2017, from
https://www.nhs.uk/conditions/clinical-depression/treatment/
National Institute for Health and Clinical Excellence. (2009). Depression in Adults: Recognition and
Management Clinical Guideline: NICE Guideline [CG90]. National Collaborating Centre for
Mental Health, (April).
Paths for all. (2014). Paths for all. Retrieved February 8, 2017, from https://www.pathsforall.org.uk
Paths for all. (2017). Step count. Retrieved December 8, 2017, from http://stepcount.org.uk/
Perraton, L. G., Kumar, S., & MacHotka, Z. (2010). Exercise parameters in the treatment of clinical
depression: A systematic review of randomized controlled trials. Journal of Evaluation in
Clinical Practice, 16(3), 597–604.
Physical Activity Guidelines Advisory Committee. (2008). Physical Activity Guidelines Advisory
Committee Report. Washington, DC.
Rethorst, C. D., Wipfli, B. M., & Landers, D. M. (2009). The antidepressive effects of exercise: A
meta-analysis of reandomized trials. Sports Medicine, 39(6), 491–511.
Rimer, J., Dwan, K., Lawlor, D. A., Greig, C. A., McMurdo, M., Morley, W., & Mead, G. E. (2012).
Exercise for depression. Cochrane.Database.Syst.Rev., 7(1469–493X (Electronic)), CD004366.
Robertson, R., Robertson, A., Jepson, R., & Maxwell, M. (2012). Walking for depression or
depressive symptoms: A systematic review and meta-analysis. Mental Health and Physical
Activity, 5(1), 66–75.
B125502
14
Royal College of Psychiatrists. (2012). Physical activity and mental health. Retrieved December 8,
2017, from http://www.rcpsych.ac.uk/healthadvice/treatmentswellbeing/physicalactivity.aspx
Scottish Association for Mental Health. (2017). Five ways to better mental health. Retrieved from
https://www.samh.org.uk/about-mental-health/self-help-and-wellbeing/five-ways-to-better-
mental-health
Stanton, R., & Reaburn, P. (2014). Exercise and the treatment of depression: A review of the exercise
program variables. Journal of Science and Medicine in Sport, 17(2), 177–182.
Stathopoulou, G., Powers, M. B., Berry, A. C., Smits, J. a J., & Otto, M. W. (2006). Exercise
interventions for mental health: A quantitative and qualitative review. Clinical Psychology:
Science and Practice, 13, 179–193.
Wittchen, H.-U., & Hoyer, J. (2011). Klinische Psychologie & Psychotherapie (2nd ed.). Heidelberg:
Springer.
World Health Organization. (2010). Global recommendations on physical activity for health. World
Health Organization. Geneva.
World Health Organization. (2017). Depression Factsheet. Retrieved October 4, 2017, from
http://www.who.int/mediacentre/factsheets/fs369/en/
