Brain Story Certification: Module 8

In this section, the area of inquiry is focused on brain circuits that mediate between inhibition and anxiety disorders.  Another area of focus is the relationship of behavioural inhibition with anxiety for some children and the features present in ADHD.  The brain circuits that influence inattention and impulsivity will be explored. There is also be an examination of the impacts ADHD has on increasing vulnerability o young adult psychopathology (Alberta Family Wellness Institute, n.d.).

Excerpt from “Bench to Bedside Temperament & Anxiety,” Nathan Fox, PhD.

• Common behaviours of behaviourally inhibited children, under new circumstances, include:
  • Becoming quiet and watchful
  • Cessation of current activity
  • A retreat from unfamiliarity
  • A refusal to engage in interactions
• Common characteristics include:
  • Low self-esteem
  • Poor peer relationships
  • Victims of bullying
  • Cortisol levels elevated in the morning.
  • An enhancement of autonomic activity
  • Enhanced startle responses
• Some continue with these patterns throughout life, while others, from the outside, do not appear to differ from the average population.
  • We can see this play out in a strange situation with prolonged attachment to the parent, and not connecting with the stranger while the secure attachment figure is in the same room.
  • In a situation where the child can play with peers (free play), the child seeks to not engage in play, and remain with the secure attachment figure. Socially reticent behaviour can be observed in the child.  This happens throughout the child’s development.
  • The children as adolescents, who had a stable temperament of socially reticent behaviour, have a higher lifetime percentage of DSM diagnosis – particularly anxiety.

Excerpt from “Bench to Bedside Termerament & Anxiety,” Nathan Fox, PhD.

•  The amygdala is the neural system that underlies conditioned and unconditioned states of fear.
• LeDoux and Davis are researchers who pioneered work on this topic.
• The amygdala model can be applied to the behavioural inhibition observed.
• Children with more significant inhibition may have higher activation of the amygdala.  This was done through brain state comparisons.
• Two cognitive processes moderate behavioural inhibition:
  • Attention biases to threat
  • Cognitive control
• Bias scores show vigilance as a positive score and avoidance as a negative score.
• Visual Probe tasks, as an implicit learning task, help researchers see where individuals put their focus.
• Amygdala is involved in immediate threat detection.  The ventral lateral prefrontal cortex down-regulates the amygdala.
• Individuals with high behavioural inhibition show an attention bias to harmful stimuli, while those without the behavioural inhibition show an attention bias towards positive stimuli.  This is correlated with anxiety symptoms and happens throughout the child’s development.  The research has been replicated amongst 2 cohorts.
• The greater the amygdala activation, the higher the anxiety symptoms.  The greater the ventral lateral prefrontal cortex activation, the less prominent the anxiety symptoms are.

Excerpt from “Bench to Bedside Temperament & Anxiety,” Nathan Fox, PhD.

• Children with the temperament of inhibition also display the same pattern of attention.  The increased likelihood of DSM diagnoses is not limited to one single DSM diagnosis.  Across the board is anxiety disorders in general.
• MacLeod Design – Testing causal nature of attention bias – successful in modifying attention bias through design linking anxiety with attention bias.  This was replicated with 9-year-olds.
• The MacLeod design was flipped to see how anxiety could be reduced as an intervention.  The training was reversed to explore a response.  The design put the dot behind the neutral face – so individual learns to implicitly learn to pay attention to the non-threatening stimulus.
• It is unsure how many training trials are needed.  Does this need to be administered in a specific environment or in the individual’s home – to be determined? 2x a week for 4 weeks has been tested, showing significant reductions in a neutral environment.

Excerpt from “Genetic, Biological, & Environmental Risk Related to Inattentive & Impulsive Behaviour,” Stephen Hinshaw, PhD.

• Attention has several forms:
  • Automatic/spacial
  • Selective
  • Sustained
  • Capacity/load
• Each attention process has its own neural identity.  Attention outcomes are strongly linked with academic issues and substance abuse.
• Hyperactivity/Impulsivity
  • Easier to identify and detect – often disrupt classrooms/homes.
  • Related to “response inhibition.”
    • Ability to disengage from a previously rewarded response tendency
    • There are neural correlates and pathways in response inhibition.
    • Impacts social interaction
  • Temperament – the early styles of interaction with the environment are often viewed as being biologically determined.
  • Hyperactivity/impulsivity linked to “negative affect.”
  • Inattention/disorganization linked to “effortful control” that doesn’t operate until 1 year of age.
• Temperament is not biologically determined – it is a product of the child’s responses and interactions with their environment.
• Effortful control comes after 1 year of age – has an impact on, or relationship with,  executive function.
• The Barkley model looks at reduced response inhibition has a precursor towards disrupted task performance because the executive function does not have an opportunity to become engaged.
• Response inhibition and executive function both exist on a bell curve in the population.  Being on the extremes of either bell curve are often diagnoses with ADD/ADHD for characteristics such as:
  • Inattentive presentation.
  • HI, presentation.
  • Combined presentation.
  • “High” on an absolute scale or as compared to age and sex norms.
• There are a lot of reasons for the extremes of over-under diagnosis.
• Impairment can lead to:
  • Academic and vocational underdevelopment
  • Social/peer rejection
  • Family struggles with reciprocal chains of bi-directional influences.
  • Accidental injury over the lifespan
  • Less independence
  • Impairment happens regardless of comorbidity.
• The title of the diagnosis is a syndrome, not a disorder.
• There are a lot of sex differences (3:1) in a representative population.
  • Boys to girls 3:1
  • The first 10 years of life are the risk period for boys, 10-20 is the risk period for girls.

Excerpt from “Genetic, Biological, & Environmental Risk Related to Innattenive & Impulsive Behaviour,” Stephen Hinshaw, PhD.

• Multiple models are used – huge vulnerability among and within individuals with ADHD.
• There is intrasubject variability in many current models.
• Cognitive models look at sustained attention, response inhibition and working memory (executive function).  They are not specific enough – looking only at subgroups.
• Motivation models – rewarding undersensitivity.
• The models miss some other mechanisms that come into play or interact.
• In the reward circuitry in the never medicated had 40% receptors for dopamine.  Dopamine transmission may thus be a contributing factor.
• There is an overall lowered cerebral volume—8-10 % smaller.
• Delayed patterns of cortical thickening/thinning in ADHD over comparative samples over time.
• There is a 3.5-year delay in ADHD groups – immaturity comes to life with intricate patterns in adolescence.  The process is the same as in the remainder of the population, just different timing.  Cortical thickening/thinning is different than the overall population.
• The evidence relates to frontal-striatal paths in WM and response inhibition.
• Etiology
  • Heritability and genes – 75-80% for characteristics that lead to a diagnosis.  There is a genetic proclivity.
  • Social class, which influences gene-environment influences, can also impact there heritability rate of characteristics that would lead to a diagnosis.
• Other risk factors include:
  • Low birthweight
  • Teratogenic effects (environment toxins)
  • Early parenting – although no consistent causal evidence.
  • Attachment does not reliably predict but may influence more extreme cases of ADD/ADHD.
  • Early maternal insensitivity may have an influence.
  • Deprivation with others in the first 4 years
• Developmental paths (Campbell)
  • Preschool manifestations
  • Careful evaluations of 3-4 /yo with prospective predictions in mid-late childhood
  • Discourses of the child growing out of it and early medication intervention were debunked.
  • Predictive factors for ADHD were:
    • Early severity of symptoms
    • Negative early parent-child interactions when controlling for symptom severity.  The parental response is essential in child outcomes.
• Predicting parenting influences on positive peer status
  • ideas of parenting
  • Factors of parenting – authoritarian, authoritative, permissive
  • Mothers of ADHD boys – rated lower on authoritative parenting measures.  Variance in the ADHD group was equivalent to a comparison group.
  • Authoritarian and permissive beliefs did not predict the peer status of children, but authoritative parenting did.
  • The relationship applied to the ADHD group – with a central theme of firm yet affirming parenting styles.
  • Moral forces that shape the initial paths may not be the same as those that maintain/worsen/protect the child later in development.
• Sex differences
  • The group with lower prevalence must have more and stronger risk factors.
  • Girls show many of the same problems as boys in childhood.  between the 10-year timespan, the females lose enough symptoms to no longer fit the diagnosis of ADHD.
  • Self-harm behaviours are still high.  This is especially the case in those who are  experiencing disinhibition.
  • Depressive symptoms also area mediating factor.
•  High levels of inattention come with a high risk of substance use
  • School failure a potential influencing factor
  • Comorbid oppositionality and aggression
  • Self-medication hypothesis
• Medication is more effective than intensive intervention work with a client on attentional measures.  However, in a followup, considerations for anti-social behaviour and internalizing behaviours and social/executive functions need to be considered.  Combined treatment with medication leads to dramatic improvement.  Skill building is very important!