Depression & Anxiety – Physical Activity: Exam Notes (EXERSCI307)

Depression

  • Defining depression

    • Episodes of unhappiness and low mood affect most people from time to time and are considered normal.
    • Low mood becomes problematic when:
    • It is recurrent and persists over time
    • It interferes with ability to function in work or relationships or other important life domains
    • More extreme dissatisfaction with life is present that may cause suicidal ideation or attempts

  • What role might physical activity play in depression?

    • PREVENTION
    • TREATMENT
    • DEPRESSION and physical activity: prevention and treatment roles

  • Physical activity and the prevention of depression

    • 25/30 studies found a significant inverse relationship between physical activity and follow-up depression.
    • Being active (walking) for 120 minutes/week120\ \text{minutes/week} reduces risk of depression by 63%63\%.
    • People who reduced their activity levels over time were 10×10\times more likely to develop depression.
    • Increasing activity levels over time reduces subsequent depression.
    • Maintaining activity levels lowers the risk of depression.
    • Source: Mammen & Faulkner 2013

  • Pearce et al., 2022 synthesis (prevention):

    • 15 studies — 191,130 participants — 2,110,588 person-years.
    • Participants who did half of the recommended PA show an 18%18\% risk reduction; those doing the recommended amount show an 25%25\% risk reduction.
    • Diminishing potential benefits and higher uncertainty for higher doses.
    • If inactive adults become active, 11.5%11.5\% of depression cases could have been prevented.

  • Australian Longitudinal Study (Currier et al., 2020)

    • 13,884 men; those doing 150 min/week150\ \text{min/week} MVPA had a lower prevalence of depression.
    • >150 min/week150\ \text{min/week} of MVPA further reduced depression rates.
    • Substituting 1 hour1\ \text{hour} of vigorous for moderate activity reduces the odds of depression symptoms by 32%32\%.
    • Physical activity could be a great low-cost, low-stigma solution for men’s mental health.

  • Typical treatment of depression

    • Pharmacological (e.g., antidepressant medication) is the most frequently used treatment.
    • Psychological (e.g., cognitive-behavioural therapy by a trained practitioner).

  • Physical activity in the treatment of depression

    • Cooney et al., 2013; Korczak, 2017; Joshi, 2016:
    • ORs show several trials reported no difference between exercise and psychological therapy.
    • 4 trials reported no difference between exercise and antidepressant therapy.
    • ADULTS: Effect size of −0.62-0.62 for exercise compared with control treatment.
    • CHILDREN: Significant ES −0.14-0.14.
    • OLDER ADULTS: Those who did more activity (ES around 0.450.45) and walkers (ES around 0.580.58) had lower odds of depression.

  • How does it work? (Depression)

    • Biochemical: β–endorphin, 5−HT, BDNF\beta\text{–endorphin},\ 5{-}HT,\ BDNF
    • Physiological: fitness adaptations, thermogenesis, cerebral blood flow, neuroplasticity, reduces inflammation
    • Psychosocial: competence perceptions and self-efficacy; social affiliation
    • Source: Kandola et al., 2019

  • Dosage: How much? (Depression)

    • Low dose (LD): 7 kcal/kg/week7\ \text{kcal/kg/week}
    • Public health dose (PHD): 17.5 kcal/kg/week17.5\ \text{kcal/kg/week}
    • Source: Dunn et al., 2005

  • Dosage: What should I do?

    • 1) Enjoyable – try different things and find an activity that is fun for you.
    • 2) Help you feel more competent or capable – such as walking, gardening or DIY.
    • 3) Give you a sense of control over your life – it isn’t helpful if you feel you have to exercise; these should be your choices.
    • 4) Help you escape the pressures of your life.
    • 5) Be shared – the companionship can often be as important as the activity.
    • Source: www.rcpsych.ac.uk

Anxiety

  • Defining anxiety

    • Anxiety exists on a continuum from transient feelings of worry in response to circumstances to more persistent and debilitating worry that interferes with functioning in work, study, and relationships.
    • Help is generally not sought or needed at lower levels; help for symptoms is sought or needed and a clinical diagnosis may be given at higher levels.
    • Increasing duration of symptoms and increasing interference of symptoms.

  • What role could physical activity play in anxiety?

    • Physical activity may be used as a self-help strategy to alleviate feelings of worry.
    • Physical activity may be investigated as a strategy for risk reduction or treatment.

  • Physical activity and prevention of anxiety

    • A role for physical activity in prevention of anxiety is less clear than for depression.
    • Difference was significant: regular physical activity is associated with a significantly reduced prevalence of anxiety disorders.
    • Anxiety is associated with low physical activity levels (OR 1.431.43).
    • Goodwin, 2003; Stubbs, 2017.

  • Prevention data (anxiety) – illustrative findings

    • Association between anxiety disorders and regular physical activity showing lower odds with regular activity across disorders (agoraphobia, social phobia, specific phobia, GAD, panic attacks) in several cohorts.
    • Generalized anxiety disorder: lower odds with regular activity in multiple studies (e.g., McDowell et al., 2018; Ströhle et al., 2007; ten Have et al., 2011; Ivanova et al., 2016).

  • Physical activity and treatment of anxiety

    • Exercise vs no treatment control: ES = -0.48 (49 RCTs).
    • Exercise vs other treatments: ES = -0.19 (27 RCTs).
    • Superior effects observed for sessions of about 21−30 min/day21{-}30\ \text{min/day}.
    • Dosage: 30 min/day30\ \text{min/day} is a common target.
    • Modality: aerobic activity; emphasis on moderate to vigorous intensity.
    • Source: Wipfli et al., 2008

  • How does it work? (Anxiety)

    • Biochemical: β–endorphin, 5−HT, Growth hormones, BDNF\beta\text{–endorphin},\ 5{-}HT,\ Growth\ hormones,\ BDNF
    • Physiological: cerebral blood flow; neuroplasticity
    • Psychosocial: anxiety sensitivity; competence perceptions and self-efficacy; distraction or “time out”
    • Source: Anderson et al., 2013

  • Additional considerations

    • Social anxiety: avoidance of group-based physical activities or physical activity in the presence of others.
    • Panic disorder: fear of strenuous activity due to discomfort in activity-induced bodily sensations.
    • Depressive disorders: low energy and lack of interest in activity engagement; tendency toward withdrawal.

  • Summary

    • Examined the complex effects of exercise to improve stress, anxiety and depression.
    • Key articles support the following findings:
    • Being active can play a role in the prevention of depression.
    • Exercise may play a critical role in the treatment of depression.
    • Being active reduces the odds of anxiety symptoms and anxiety disorders.
    • About 30 minutes per day of physical activity appears to be an effective treatment of anxiety.
    • Discussed the role of exercise in the pandemic.
    • Considered key elements such as dosage, intensity, type and age that play a role in studies and findings.