Week 11 - Exercise and mental health

Question 1

Mental illness

Answer 1

Disorders of mood, thinking and behaviour with impaired daily functioning (e.g. depressive disorders, anxiety disorders, sleep disorders, substance use disorders, eating disorders)

Over 300 diagnosable mental disorders

Question 2

Severe mental illness (SMI):

Answer 2

Psychotic disorders including schizophrenia, bipolar disorder, or a mental disorder causing significant functional impairment

Question 3

Global prevalence of mental disorders (Ferrari et al 2022):

Answer 3

• Prevalence of mental disorder 12,260 per 100,000 (12.3%)
• Depression, eating and anxiety disorders are far more common in females than males
• ADHD is more common in males

Question 4

Risk factors for mental disorders:

Answer 4

• Physical inactivity
• Genetic vulnerability – for depressive disorders, heritability is around 40%, for schizophrenia, bipolar, ADHD, heritability is ~70%
• HPA-axis dysfunction
• Hormonal changes
• Chronic inflammation
• Substance use
• Poor nutrition
• Head injury
• Personality
• Chronic illness or pain
• Loneliness
• Low socioeconomic status
• Stressful life events
• Early life trauma

Question 6

Burden of mental ill health:

Answer 6

• Global ranking for mental disorders: 2nd (YLD); 22nd (YLL); 6th (DALY)- Institute for health metrics and valuation 2021
• Mental disorders rank 2nd on YLD, musculoskeletal disorders rank 1st
• Disability adjusted life years: a measure of overall disease burden, expressed as the cumulative number of years lost due to ill-health, disability or early death = Years lived with disability (YLD) + years of life lost (YLL)
• Personal burden: psychological distress, stigma and discrimination, poor physical health, suicide
• Societal burden: healthcare costs, reduced productivity, absenteeism, welfare payments

Question 7

Severe mental illness and physical ill-health (Reilly et al 2015)

Answer 7

High prevalence of health conditions associated with mental illness e.g., hypertension, diabetes, chronic kidney disease, asthma, osteoarthritis, hypothyroidism, stroke, CHD
- Related to lifestyle factors e.g., diet and inactive
- Medications can lead to weight gain
- Physical health gets neglected whilst managing mental

Question 8

Comorbid depression and physical health: Moussavi et al 2007

Answer 8

Looked at the health status within a population based sample. Found that comorbid depression incrementally worsens health

Depression worsens other health conditions
People with 2 physical health conditions have a better health status than those with 1 physical health condition and depression

Depression associated with – disrupted appetite, sleep, higher stress levels (cortisol), lower immune function.

Question 9

NICE guidance for Psychosis and schizophrenia: prevent and management:

Answer 9

• Patients should be offered a healthy eating and physical activity programme especially those on antipsychotics.

Question 10

NICE guidance for depression: treatment and management:

Answer 10

• Discuss current lifestyle (diet, physical activity, sleep) during assessments.
• Advise that regular physical activity (such as walking, jogging, swimming, dance, gardening) could help wellbeing, particularly if outdoors

Question 11

NICE guidance for generalised anxiety disorder and panic disorder: management:

Answer 11

• The benefits of exercise as part of good general health should be discussed

Question 12

Exercise for preventing depression: Hallgren et al 2019

Answer 12

13 year follow up study on 21,902 health adults- after the follow up 364 were diagnosed with depression.
assessed PA (adjusted for sex, age, occupation, BMI, smoking, comorbidities & baseline depression symptoms)
* Depression Risk is reduced by around 29% in those who exceed
PA guidelines (more than 300mins/week)
- more PA = reduced risk

Question 13

Meta-analysis of cohort studies on depression: Pearce et al 2022

Answer 13

• 15 large prospective cohort studies ≥3y (n = 191,130) assessing leisure exercise and depression diagnoses
• Estimated population risk: 11.5% of depression cases prevented if all adults met PA recommendations (8.8 met-h/w)
• Those who completed low levels of PA (4.4met h/w), still had a significantly reduced risk of depression.

Question 14

• Meta-analysis of 8 cohort studies for anxiety disorders (Schuch et al 2019)

Answer 14

• Higher exercise reduced odds of developing any disorder (~25% reduction- odds ratio = 0.75* compared to those who are physically inactive)
• 2 studies of agoraphobia (adjusted OR = 0.43*)
• 2 studies of PTSD (adjusted OR = 0.58*)

Question 15

• Meta-analysis of 4 cohort studies for psychosis or schizophrenia (Brochmeier et al 2020):

Answer 15

• A reduced risk was not found for psychotic disorders

Question 16

Genetic pleiotropy: (De Geus 2021):

Answer 16

• Heritability indicated for exercise behaviour (~40%) and for mental ill-health outcomes (depression ~40%, anxiety ~40%, schizophrenia ~70%).
• Potential for genetic confounding through overlapping genetic variants that independently influence both exercise behaviour and mental health (pleiotropy).
• Increases the challenge of determining the causal effects of exercise behaviour.

Question 17

Genetic vulnerability for depression (Choi et al 2020):

Answer 17

• 2-year cohort (n = 7968) of exercise and depression cases (adjusting for prior depression, BMI, employment, education)
• Depression cases among high exercise (≥3h/w) and low exercise (0-1h/w) categories across polygenic risk levels
• Conclusion = Regular exercise offsets genetic risk for depression. Even for high-risk group (OR 0.82)

Question 18

Symptomology:

Answer 18

Depressive disorders: Low mood, Loss of interest, Sleep problems, Appetite changes, fatigue, poor concentration, low self-worth, psychomotor retardation, rumination, social withdrawal

Anxiety disorders: Excess worry, muscle tension, restlessness, sleep problems, inattention, fatigue, irritability, fear, panic attacks, avoidance

Question 19

Clinical evidence of exercise for depression: Morres et al 2019:

Answer 19

• Meta-analysis of 11 randomised controlled trials of adults with depression diagnosis recruited from mental health services
• Aerobic exercise programmes versus non-exercise controls (e.g. usual care, counselling, medication, occupational therapy)
• Found that depression was reduced following the exercise programs in comparison with controls (effect size = 0.8)
• Pts with moderate-severe and mild-moderate depression benefit
• Outdoor exercise was slightly more beneficial than indoor exercise

Question 20

Exercise modality: Noetel et al 2024:

Answer 20

• Meta-analysis of 218 randomised trials (n = 14,1700) of exercise for depression (diagnosis or symptom screening)
• Clinically significant effects of exercise on depression diagnosis and symptoms
• Adherence best for yoga and strength training

Question 21

Treatment recommendations for less severe disorders: National Institute for Health & Care Excellence 2022:

Answer 21

• Education, active monitoring, guided self-help, mindfulness, group or indiviudal psychotherapy, antidepressant medication
• Exercise programmes: Delivered in groups (~8) by trained practitioner >1 weekly for 10w - Includes moderate intensity aerobic exercise

Question 22

Mechanisms of exercise on depression (Kandola et al 2022): Neurophysiological:

Answer 22

Neuroplasticity (e.g. BDNF level, hippocampal size), Neurogenesis, HPA axis (exercise reregulates HPA axis), neurochemistry, oxidative stress, chronic inflammation
- Exercise has neuroplastic properties – helps increase the hippocampus size (those with depression have been shown to have a hippocampus reduced in size)
- Depression has been linked to inflammatory responses – exercise reduces inflammation
- Neurochemical – exercise increases synthesis of neurotransmitters: serotonin, dopamine etc – exercise may mimic the effects of antidepressant drugs which work via increasing the uptake of serotonin

Question 23

Mechanisms of exercise on depression (Kandola et al 2022) - Psychosocial:

Answer 23

• Exercise can increase positive self-perceptions which are vital for good health (e.g., self-esteem, self-efficacy)
• Exercise acts as a distraction from negative thought cycles (e.g., rumination, anxious thoughts)
• Exercise as part of a group increases social support – low social support isa large risk factor for depression