Regulation of Emotions: Sadness and Depression

Overview

• Aim: To introduce issues in the regulation of emotion through depression and sadness.
• Background on mental health and depression
• Biology of normal mood: emotions vs feelings
• Animal models of depression
• Depression as a biologically adaptive process in normality

How Common is Depression?

• National health survey: 2017-2018 financial year Australia (from ABS)
  • 20% or 4.8 million Australians had a mental or behavioural condition, an increase from 18% in 2014-15.
  • 13% or 3.2 million Australians had an anxiety-related condition, an increase from 11% in 2014-15.
  • 10% had depression or feelings of depression, an increase from 9% in 2014-15.

Global Burden of Disease

• DALY (Disability Adjusted Life Year): Measure of overall disease burden, expressed as the cumulative number of years lost due to ill-health, disability, or early death.
• YLD (Years Lived with Disability)
• YLL (Years of Life Lost)
• Healthy life vs. Disease or Disability vs. Early death

Leading Causes of DALYs (All Ages)

1990

1. Neonatal disorders: $10.6\%$
2. Lower respiratory infections: $8.7\%$
3. Diarrhoeal diseases: $7.3\%$
4. Ischaemic heart disease: $4.7\%$
5. Stroke: $4.2\%$

2019

1. Neonatal disorders: $7.3\%$
2. Ischaemic heart disease: $7.2\%$
3. Stroke: $5.7\%$
4. Lower respiratory infections: $3.8\%$
5. Diarrhoeal diseases: $3.2\%$
   …
6. Depressive disorders: $1.8\%$
7. Anxiety disorders: $1.1\%$

Leading Causes of DALYs (Ages 10-24)

1990

1. Road injuries: $7.8\%$
2. Self-harm: $4.9\%$
3. Headache disorders: $3.8\%$
4. Tuberculosis: $3.6\%$
5. Diarrhoeal diseases: $3.2\%$
   …
6. Depressive disorders: $2.8\%$
7. Anxiety disorders: $2.6\%$

2019

1. Road injuries: $6.6\%$
2. Headache disorders: $5.0\%$
3. Self-harm: $3.7\%$
4. Depressive disorders: $3.7\%$
5. Interpersonal violence: $3.5\%$
6. Anxiety disorders: $3.3\%$

Rank of Mental Disorders Among Causes

• All mental disorders:
  • DALYs: Ranked 2nd in 1990, 2010, and 2019.
  • Deaths: Ranked 21st in 1990, 2010, and 2019.

Composition of DALYs by Constituent Level 3 Causes (2019)

• Major depressive disorder
• Dysthymia
• Anxiety disorders
• Schizophrenia
• Bipolar disorder
• Autism spectrum disorders
• Conduct disorder
• Idiopathic developmental intellectual disability
• Other mental disorders

How Does Depression Present?

• Sad or low mood
• Loss of interest or pleasure (anhedonia)
• Significant loss or gain of appetite (or weight)
• Insomnia or excessive sleep (hypersomnia)
• Physical and mental slowing or agitation
• Fatigue or loss of energy
• Feelings of worthlessness or excessive guilt
• Impaired thinking or concentration; indecisiveness
• Suicidal thoughts, thoughts of death
  • Lasting at least 2 weeks

Other Expressions of Depression

• Social withdrawal
• Reckless behaviour – e.g. driving, gambling
• Alcohol or substance abuse
• Irritability, anger
• Violent suicide attempts
• Excessive work hours / other distracting behaviour

Why Do People Become Depressed?

Triggering Factors

• Stressful life events (usually some experience of loss; or feeling emotionally trapped in a situation; or a sense of humiliation or shame)
  • Separation from a loved one
  • Threat of separation
  • Infidelity
  • Relationship problems commencing or increasing
  • Illness, injury, accident
  • Bereavement (worse if child or spouse)
  • Loss of job, unemployment
  • Discrimination – LGBTIQ, Indigenous
  • Acute financial difficulties
  • Increased responsibility
  • Injury to pride/reputation

Predisposing Factors

• Genetic make-up can make us more vulnerable to becoming depressed on exposure to stressful life events.
• Genes alone don’t cause depression.
• In elderly, depression more likely with brain small blood vessel disease.

Depression - Risk Factors model

• Genetic Risk
• Childhood adversity
• Chronic anxiety and subclinical depression
• Life events and chronic difficulties
• Low self-esteem
• Social Support (protective factor)

What are emotions? (“The Feeling of What Happens” Antonio Damasio, 1999)

• Emotions are not just feelings; they exist on a continuum:
  • Emotions: collections of chemical and neural responses.
    • Role is to assist organism in maintaining life
    • Biologically determined
    • Automatic, not conscious
    • Use the body as their theatre (internal milieu, visceral, vestibular and musculoskeletal systems)
    • Affect brain circuits -> neural patterns which become ‘feelings’
  • Emotions are external (body), feelings are internal

Levels of Life Regulation

1. High Reason
   • Complex, flexible, and customized plans of response are formulated in conscious images and may be executed as behavior.
2. Feelings
   • Sensory patterns signaling pain, pleasure, and emotions become images.
   • CONSCIOUSNESS
3. Emotions
   • Complex, stereotyped patterns of response, which include secondary emotions, primary emotions, and background emotions
4. Basic Life Regulation
   • Relatively simple, stereotyped patterns of response, which include metabolic regulation, reflexes, the biological machinery behind what will become pain and pleasure, drives and motivations

Types of Emotions

Primary (Universal) Emotions

• Happiness
• Sadness
• Fear
• Anger
• Surprise
• Disgust

Secondary (Social) Emotions

• Embarrassment/Shame
• Guilt
• Jealousy
• Envy
• Contempt (biological metaphor for disgust)

Background Emotions

• Well-being vs. malaise
• Calm vs. tension

Shared Biology of Emotions (Damasio)

• Emotions are complicated collections of chemical and neural responses.
• All emotions have some kind of regulatory role to play.
• They lead to the creation of circumstances advantageous to the organism, i.e., they assist the organism in maintaining life.
• Emotions are biologically determined processes, depending on innately set brain devices, laid down across a long evolutionary history.
• Learning and culture can alter the expression of emotions and give them new meanings.
• The neural devices which produce emotions occupy a restricted sample of mostly subcortical regions, beginning at the level of the brain stem and moving up to the higher brain.
• All the neural devices can be engaged automatically, without conscious deliberation.
• The emotions are fundamentally stereotyped, automatic and regulatory in purpose – any variations are shaped by individual variation and culture.
• All emotions use the body as their theatre:
  1. humoral/bloodstream (internal milieu)
  2. neural: visceral, vestibular and musculoskeletal systems
• Emotions affect the mode of operation of numerous brain circuits; these changes lead to the experience of “feelings”.
• Emotions alter activity in other brain regions via monoamines/peptides and trigger behaviours e.g. playing, bonding, crying.

Principal Emotion Induction Sites

• Amygdala
• Ventromedial prefrontal
• Brain-stem nuclei
• Hypothalamus and basal forebrain

Feelings

• Feelings are brain representations of emotions (derived from changes in body and brain).
• We have a feeling when we know that the emotion is happening in our us i.e. feeling is the result of a relationship between the organism and the emotion.

Background Feelings

• These are from background emotions and the latter might be observable to others e.g. body posture, speed of movements, tone of voice etc
• Examples include fatigue, energy, excitement, wellness, sickness, tension, relaxation, harmony, discord
• The relationship between background feelings and moods is close. Moods are made up of modulated and sustained feelings of primary emotions – sadness in the case of depression.

What Adaptive Role Does Sadness Play?

• We are social beings – perhaps sadness is a means of temporary withdrawal to cope with loss of relations.
• Other more conceptual losses (health, status, etc.) may be elaborations of this with our more complex brains.
• Depression is presumably a pathological distortion of normal sadness.
• Communicating a need for help, yielding in a hierarchy conflict, fostering disengagement from commitments in unreachable goals.
• Low mood may increase an organism's ability to cope with the adaptive challenges characteristic of effort to pursue a major goal will likely result in danger, loss, bodily damage, or wasted effort.
• In such situations, sadness/depression may give a fitness advantage by inhibiting certain actions, especially futile or dangerous challenges to dominant figures, efforts that would damage the body etc.

Summary

• Emotions
• Feelings
• Depression a pathological distortion of sadness (next lecture Treatment Choices in Depression)