Exercise and Depression in the General Population Flashcards

1
Q

cross-section studies

A
  • > cross-sectional (observational) study compares different population groups at a single point in time
  • > yoshiuchi et al., 2006 showed that daily step count and daily duration of moderate intensity PA were significantly and inversely correlated with depression
  • > physical activity goes up, depression symptoms go down
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2
Q

longitudinal studies

A
  • > longitudinal study researchers conduct several observations of the same subjects over a period of time
  • > paffenbarger et al. (1994)
  • > participants were split into 1 of 3 weekly energy expenditure (EE) categories, <1000, 1000-2499, 25000+ kcal/week
  • > those with the highest weekly EE were 28% less likely to develop depression than the lowest weekly EE group
  • > those with moderate weekly EE were 17% less likely to develop depression than the lowest weekly EE group
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3
Q

effects of exercise training on older patients with major depression (blumenthal et al.)

A

background: exercise training may reduce depressive symptoms in older patients with major depressive disorder (MDD)
objective: to asses the effectiveness of an aerobic exercise program compared to standard medication (antidepressants)
methods: 156 men & women with MDD randomly assigned to exercise, antidepressant medication or combined exercise and medication

treatment period: 16 weeks

primary outcome: better scores of Hamliton Depression Scale and Beck Depression Inventory

secondary outcome: aerobic capacity, life satisfaction, self-esteem, anxiety and dysfunctional cognitions

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4
Q

conclusion of exercise training and major depressive disorder

A
  • > an exercise training program may be considered an alternative to antidepressants for treatment of depression in older persons
  • > after 16 weeks of treatment, exercise was equally effective in reducing depression among patients with MDD
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5
Q

statistically significant change

A

=> usually focus on statistical significance to discuss effectiveness of an intervention, meaning the change is likely not by chance. however, this does not necessarily mean that it is clinically important

=> Centre for Epidemiological Studies - Depression (CES-D)

= or > means at risk for depression

=> statistical significance would be comparing the mean of two groups and seeing if there is a difference

=> this does not mean their score improved clinically

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6
Q

prenatal depression

A
  • > affects up to 20% of all pregnancies
  • > 19% will continue to have depressive symptoms postpartum
  • > can negatively impact growing fetus: preterm birth, intrauterine growth restriction, early cessation of breastfeeding
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7
Q

prenatal depression treatment options

A

=> pharmacological treatment options are often avoided

=> most women go untreated

=> recent literature has shown that exercise may prevent prenatal depression

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8
Q

clinically reliable change criteria

A

reliability: if measures were repeated in the same population you would see the same results

clinically important: practical importance of the treatment effect being observed

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9
Q

purpose and method of physical activity and prenatal depression study

A

purpose: to determine if prenatal exercise during pregnancy can treat depression among women who enter pregnancy at risk for depression and if exercise can have a clinically reliable change on depression risk during pregnancy
method: randomized controlled trial: exercise group and standard care control group

group fitness class 3 / per week

aerobic training and resistance exercises

baseline: 9-12 weeks

completion 36-38 weeks

at baseline and at the end, completed the CES-D

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10
Q

calculating the clinically reliable change criteria

A
  • the reliability of the measurement (Cronbach’s alpha) (0.752)
  • standard deviation for the current population
  • standard error of difference between scores at 2 time points (3.6)
  • gives clinically reliable change criteria (7.09 -> 7 - how many of the treatment patients reduced the depression symptom on the CES-D by atleast 7 points)
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11
Q

results of exercise and prenatal depression study

A
  • 61 women included (36 exercise, 25 control)
  • assessed potential confounding variables: age, pre-pregnancy BMI, smoking status, education level, occupation, previous miscarriage incidence, parity, weight gain
  • no difference observed from intervention and control groups
  • >7 point decrease in CES-D scores and below 16, control reduced score by 3 points
  • 22 women (61%) had a score decrease by 7 points in the EG compared to 8 women (32%) had a score decrease by 7 points in the CG (chi square p<0.05)
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12
Q

findings on prenatal exercise and depression

A
  • prenatal exercise may have both a statistical and clinically reliable treatment effect on depression risk
  • prenatal exercise may be prescribed to treat women who enter pregnancy with depression risk
  • exercise can increase the likelihood of achieving the clinically reliable threshold
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13
Q

strengths and limitations of prenatal exercise and depression

A

strengths

  1. first study to calculate and apply clinically reliable change criteria for this population; calculation can be used for other outcomes
  2. only included women with a CES-D score greater or equal to 16

limitations

  1. convenience sample used
  2. group dynamics not assessed
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14
Q

future steps for prenatal exercise and depression studies

A
  • design a prenatal exercise intervention based study with an priori sample size calculation specifically for women at risk for prenatal depression
  • follow up in the postpartum period
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15
Q

by providing clinical evidence for prenatal exercise and depression

A
  • inclusion of prenatal care
  • treatment option
  • support women and the next generation in leading a healthy lifestyle
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16
Q

review of exercise for depression (cooney et al.)

A
  • found mean difference of -0.62 favoring exercise
  • concluded that the antidepressant effect of exercise may be small
17
Q

stepwise reduction effect over time

A
  • pooled standardize mean difference (SMD) from:
  • 1.10 in 2001
  • 0.82 in 2009
  • 0.67 in 2012
  • 0.62 in 2013
  • hence an effect of 0.6 suggests that the experiemental group has a net gain of 23% over the control group
  • the score of the average person in the experimental group exceeds the scores of 73% of the control group
18
Q

demystifying the shrinkage phenomenon

A
  • applying the following rule to the data: only examine studies where exercise is compared to a passive (non-exercise) control
  • pool SMD is raised from -0.62 to -0.90
19
Q

how does exercise affect coping efficacy in those with depression?

A
  • depression is associated with low efficacious beliefs like, low confidence in ability to achieve outcomes, regulate negative cognition, cope
  • exercise leads to improved coping efficacy in those with depression
20
Q

how does chronically high levels of cortisol relate to episodic memory deficits and reduced hippocampal volume?

A
  • depression is often associated with episodic memory impairment, reduced hippocampal volume, high or dyregulated cortisol secretion
  • episodic memory processing occurs in the hippocampus and surrounding areas

- chronically high levels of cortisol independently implicated in both episodic memory deficits and reduced hippocampal volume

21
Q

how does exercise affect episodic memory?

A
  • in those with depression memory function improves with successful treatment
  • since exercise is a efficacious treatment, exercise has been shown to improve episodic memory in healthy young adults
22
Q

how does exercise affect cortisol secretion?

A
  • in those with depression cortisol secretion is normalized with successful treatment
  • since exercise is an efficacious treatment, exercise does decrease cortisol secretion in healthy adults
23
Q

how does exercise affect episodic memory and hippocampal volume?

A
  • the effect of exercise on episodic memory and hippocampal volume may be mediated through cortisol
24
Q

examination for exercise as a treatment for depression

A

procedure: participants who met criteria were randomized into a 12 week aerobic exercise or stretching intervention

participants attend sessions 3x per week for 30-40 mins

aerobic exercise group = moderate intensity, at 40-70% of Heart Rate Reserve

stretching group = mild-intensity stretching

measures:

depression - Beck Depression Inventory (BDI-II) and The Montgomery-Asberg Depression Rating Scale (MADRAS)

coping efficacy - depression coping self-efficacy scale

episodic memory - verbal recall task - uncued and cued recall

cortisol - salivary cortisol concentration at waking, 30 min post waking & before bed

cardiovascular fitness - modified Astrand-Ryhming cycle ergometer test

flexibility - YMCA Sit-and-Reach test

attendance

25
results of BDI-ll after exercise treatments
**Beck Depression Inventory:** decreased in both groups at 6 and 12 weeks decreased more in the aerobic exercise group
26
results of MADRAS after exercise treatment
**The Montgomery-Åsberg Depression Rating Scale:** decreased in both groups at 12 weeks decreased more in the aerobic exercise group
27
results of coping efficacy after exercise treatment
**Depression Coping Self-Efficacy Scale:** increased in both groups at 6 and 12 weeks coping efficacy improved more in the stretching group
28
results of un-cued recall after exercise treatment
**Un-cued recall**: improved in both groups at 6 and 12 weeks improved more in the aerobic exercise group
29
results of cued recall after exercise treatment
**cued recall**: improved in both groups at 6 weeks and leveled at 12 weeks cued recall improved more in the aerobic exercise group
30
results of CAR after exercise treatment
**cortisol awakening response**: decreased in both groups at 6 weeks decreased in aerobic exercise group increased in stretching group at 12 weeks no significant time effect significant time\*group effect (p=0.042)
31
clinical significance of exercise treatment for depression
- recent research on the BDI has shown clinical significance - clinically important reduction in symptoms: - \> cut-off score of 14.29 must be crossed in order to move from being depressed to being non-depressed - \> change in score greater than the reliable change index (RCI) of 8.46 must be observed - both exercise and stretching groups passed the cut-off - only exercise group had a change score greater than the RCI (10.6 vs 6.4)
32
conclusion of exercise treatment for depression
- participants in the aerobic exercise group showed significant reductions in depression and significant improvements in coping efficacy and episodic memory - however, these benefits also occured albeit to a lesser extent in the stretching group - study was insufficiently powered to detect statistically signifcant small to medium effects that favored the exercise condition - adherence was a problem in stretching group - exercise group satisfied both criteria for a clinically important change in depression - **both aerobic exercise and stretching seem to be good treatments for depressions with positive changes to coping efficacy and episodic memory** **however, stress (cortisol) was only positively influenced by aerobic exercise**
33
kynurenine (KYN)
- kynurenine produced mainly in the liver in response to stress that travels to the brain, where it's linked to neuroinflammation, cell death and depression - **exercise causes your muscles to increase levels** of a protein called **PGC-1alpha1**, which in turn leads to a **higher level of an enzyme** (KAT) that **converts kynurenine into kynurenic acid** (KYNA) **which can't cross into the blood-brain barrier**, **so unlike kynurenine it can't get into the brain and damage it**
34
is exercise effective as pharmacological products in reducing depression?
- exercise is just as effective as pharmacological products in reducing depression - implications: free and offeres other health benefits (fitness)