Transcript 9 The relationship between physical activity and anxiety

Chapter 9:
The relationship between physical activity
and anxiety and depression
Can physical activity beat the blues and help
with your nerves?
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!
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 crosssectional data
• review and summarise the evidence linking exercise with nonclinical 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
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
Increases in anti-depressant drug
prescriptions in England 1991-2003
30
25
20
Millions of
presciptions
15
10
5
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
0
Relationship between physical activity and
depression assessed with the CES-D
14
12
10
8
CES-D
6
4
2
0
Men <40
Much exercise
Men 40+
Women <40
Moderate exercise
Women 40+
Little/no exercise
Summary of DSM -IV criteria for major depressive episode
Category
A
A(1)
A(2)
A(3)
A(4)
A(5)
A(6)
A(7)
A(8)
A(9)
B
C
Criteria
At least five of the following symptoms have been
present during the same 2-week period, nearly every day,
and represent a change from previous functioning. At
least one of the symptoms must be either (1) depressed
mood or (2) loss of interest or pleasure
Depressed mood ( or alternatively can be irritable mood
in children and adolescents
Markedly diminished interest or pleasure in all, or almost
all, activities
Significant weight loss or weight gain when not dieting
Insomnia or hypersomnia
Psychomotor agitation or retardation
Fatigue or loss of energy
Feelings of worthlessness or excessive or inappropriate
guilt
Diminished ability to think or concentrate
Recurrent thoughts of death, recurrent suicidal ideation
without a specific plan, or a suicidal attempt or a specific
plan for committing suicide
Symptoms are not better accounted for by a Mood
Disorder Due to a General Medical Condition, a
Substance-Induced Mood Disorder, or Bereavement
(normal reaction to death of a loved one)
Symptoms are not better accounted for by a Psychotic
Disorder (e.g. Schizo-affective Disorder)
Prevalence
• Depression is one of the
most common
psychiatric problems.
• An estimated 20% of
consultees in primary
care have some degree
of depressive
symptomology.
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
odds ratio
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
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
low activity
men
w omen
moderate
high activity
activity
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.
BDI scores pre and post 16 weeks of treatment
(from Blumenthal et al, 1999) and 6 month
follow up (Babyak et al, 2000)
25
20
15
pre
post
6 mth follow up
BDI scores
10
5
0
medication
combination
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.
16
14
12
Hamilton 10
Rating Scale 8
for depression 6
4
2
0
baseline
12 weeks
placebo
control
low dose
public health
dose
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.
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.
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.
Key point:
• Mental health is a public health concern
and physical activity may assist in
prevention and treatment.
Key point:
• Exercise has a small to moderate effect
on reducing non-clinical levels of
anxiety.
Key point:
• There is too little evidence to make firm
conclusions about the role of exercise
in the prevention or treatment of
anxiety disorders.
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.
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.
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.
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 nonclinical anxiety
• large-scale epidemiological surveys offer mixed support for anxietyreducing 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.
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 nonclinical 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