Temperament and Child Psychiatric Disorders

Temperament: Risk and Protective Factors

Historical Antecedents

• Galen's Four Temperament Types:
  • Sanguine: Extraverted and stable
  • Choleric: Extraverted and unstable
  • Melancholic: Introverted and stable
  • Phlegmatic: Introverted and unstable
• Chess and Thomas:
  • Proposed nine basic dimensions of temperament.
  • Proposed three temperament types: easy, slow to warm up, and difficult.

Definition of Temperament

• Mary Rothbart: "Constitutionally based individual differences in reactivity and self-regulation."
• Key components of a temperamental trait:
  • Heritability: Genetic influence on the trait.
  • Stability: Trait is relatively stable across time.
  • Early appearance: Evident early in life, even in infancy.

Major Dimensions

• Core dimensions are structured around incentive response systems (approach and withdrawal) often merged/crossed with emotional valence.
• Common Dimensions:
  • Withdrawal and Propensity to Experience Negative Emotions: Threshold to experience negative emotions (sadness, fear, anger).
  • Approach and Positive Emotions: Degree to which a person actively engages the world and experiences positive emotions (joy, excitement).
  • Emotional Regulation and Constraint: Emotional and attentional regulation, especially when facing obstacles.
• Other Dimensions:
  • Social Affiliation
  • Activity Level
  • Behavioral Inhibition and Disinhibition

Temperament Types

• Emphasis on distinguishing groups with similar levels across traits.
• The Difficult Child: (Chess and Thomas) Low rhythmicity, low response threshold and adaptability, and high-response intensity.
• New Approaches to Temperament Types:
  • Moderate: Average levels across dimensions.
  • Steady: Low novelty seeking and high persistence.
  • Disengaged: High novelty seeking and harm avoidance, low reward dependence.

Features of Temperament

• Observed in infancy and across cultures.
• Sex Differences:
  • Women: Higher reward dependence and harm avoidance.
  • Men: Higher novelty seeking and persistence.
  • Girls: Higher effortful control, lower surgency, and equal negative affectivity.
• Continuity:
  • Temperamental traits are moderately stable across time.
  • Physiologic "footprints" of traits may persist even without observable behavior.

Neurobiology and Etiology

• Genetic Influences:
  • Twin and adoption studies suggest genetic factors explain 20-60% of variability in temperament.
  • Additive genetic influence is common; non-additive influence is less common.
• Environmental Factors:
  • Shared environmental events: Have a similar effect on all members of a family.
  • Nonshared environmental factors: Environmental events that are not shared by members of the same family.
  • More support for unshared environmental effects.
• Genetic–Environmental Interplay:
  • Bidirectional influences; environmental events can control gene expression.
  • Gene–environment correlations and interactions.
• Neurotransmitters and Brain Circuitry:
  • Negative affectivity/harm avoidance: Amygdala and its pathways, HPA axis dysregulation.
  • Novelty seeking/extraversion: Dopamine pathways.
  • Social affiliation/reward dependence: Noradrenergic pathways, serotoninergic projections, oxytocin.
  • Persistence/effortful control: Anterior cortex, dopaminergic transmission.

Temperament and Psychopathology

• Psychiatric symptoms exist on a continuum.
• Impairment is a key consideration.
• Models of Temperament/Psychopathology Associations:
  • Spectrum/continuum: Psychiatric disorders exist on a continuum with temperament traits.
  • Risk/vulnerability: Temperament increases the risk of psychopathology.
  • Common factor: Temperament and psychopathology share etiologic factors.
  • Pathoplastic: Temperament and psychopathology are distinct but have bidirectional influences.
  • Scar: Pathophysiology of psychiatric disorders alters temperament.

ADHD and Disruptive Behavior Disorders

• Low effortful control and persistence, higher novelty seeking and extraversion.
• Other disruptive disorders: Aggression, oppositionality.

Mood and Anxiety Disorders

• Strongest association: Negative affectivity, neuroticism, or harm avoidance.

Autistic Spectrum Disorder

• Low sociability/reward dependence, high negative affectivity, and low extraversion.

Other Disorders

• Substance Use Disorders: Novelty/sensation seeking.
• Eating Disorders: Low effortful control/persistence (bulimia), high neuroticism/harm avoidance.

Other Concepts in Temperament-Psychopathology Relations

• Parenting Behavior: Transactional view with bidirectional influences.
• Cognitive Factors: Moderating roles.
• Trauma and Adverse Events: Can propel temperamentally at-risk children toward psychiatric symptoms.
• Peer Groups and Activities: Can magnify maladaptive behaviors or channel tendencies productively.
• Temperament and Resiliency: Protective factors in the face of adversity; can promote mental health and wellness.
• Goodness of Fit: A cornerstone of child development theory.