ADHD - Lecture notes 3 PDF

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Head of Unit: this is week 3 lecture of ADHD in children...

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Developmental and Psychological Disorders in Children Week 2 ADHD – Attention Deficit Hyperactive Disorder By the end of this lecture, you will:

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To describe the key behaviours associated with Attention Deficit Hyperactivity Disorder To describe and evaluate the evidence presented on the multiple causes for ADHD – To critically evaluate the effectiveness and appropriateness of pharmacological and cognitive and behavioural type interventions for children with ADHD

What is ADHD?  

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A chronic, pervasive childhood disorder -> chronic = persisted, pervasive = it is everywhere, interferes with daily functions Characterised by developmentally inappropriate activity level, low frustration tolerance, impulsivity, poor organisation of behaviour, distractibility & inability to sustain attention/concentration -> related to the 3 core traits of ADHD The most common childhood referral to psychiatric and psychological services in UK -> disorder we need to be aware of ADHD is characterized by a pattern of behavior, present in multiple settings (e.g., school and home), that can result in performance issues in social, educational, or work settings -> in order to get the diagnosis, it is important to understand that ADHD is in multiple settings

Key Traits:      

Inattention AND/OR impulsivity/hyperactivity Leading to multiple types of ADHD – inattentive type – problems with inattention but not with hyperactivity and impulsivity Diagnosed through DSM-5 Six or more symptoms for children up to age 16, or five or more for adolescents 17 and older – within either inattention or impulsivity/hyperactivity Symptoms have to have been present for at least 6 months, They are inappropriate for developmental level

Presentation Different Types: 

Three main sub types: 1. Predominantly Inattentive Subtype  Clinical levels of inattention only  Often not identified until later in childhood 2. Predominantly Hyperactive/Impulsive Subtype  Clinical levels of hyperactivity/impulsivity only  More common among very young children prior to starting school 3. Combined Type  Clinical levels of both inattention and hyperactivity/impulsivity  Most common subtype

DSM-5 Criteria Inattention:

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Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities. Often has trouble holding attention on tasks or play activities. Often does not seem to listen when spoken to directly. Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace Often has trouble organizing tasks and activities. Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework). Often loses things necessary for tasks and activities Is often easily distracted Is often forgetful in daily activities. For a child, you need 6 or more symptoms to be diagnosed

DSM-5 Criteria – Hyperactive/Impulsivity:          

Often fidgets with or taps hands or feet, or squirms in seat. Often leaves seat in situations when remaining seated is expected. Often runs about or climbs in situations where it is not appropriate Often unable to play or take part in leisure activities quietly. Is often "on the go" acting as if "driven by a motor". Often talks excessively. Often blurts out an answer before a question has been completed. Often has trouble waiting his/her turn. Often interrupts or intrudes on others (e.g., butts into conversations or games) 6 or more of these symptoms needed

Assessment of ADHD:     

No simple test for ADHD Multidisciplinary assessment of ADHD i.e. school observations, interviews with parents, observations and parent and teacher ratings Diagnostic criteria that was in the DSM-5 was still general so other observations to see if the behavior is actually occurring Needs to be multiple informants and in multiple settings i.e. school and home Diagnosing ADHD starts with visit to GP – (seen as a medical condition) -> would be referred on for further support

Co-Morbidity:   

if you have one developmental disability, you are more likely to have another one such as autism, dyslexia etc. High rates of co-morbidity with other developmental and psychiatric disorders Kadesjo and Gillberg (2001) found that the majority of individuals with ADHD (87%) in their sample had at least one co-occurring disorder.  60% for Oppositional Defiant Disorder  20% for Conduct Disorder  30% for Learning disorders (Dyslexia and DCD)  14-78% for ASD (Jang et al. 2013)

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Research however, often not controlled carefully enough for comorbid conditions – therefore interpret results with caution With so much comorbidity it is difficult to unravel the causes and consequences of core problems of ADHD. Need to understand what the causes are so when co-morbidity is present, some symptoms overlap so causes are harder to find but also need to decide which interventions are important for the children – do we focus on one disability over the other? Or do we use a combined approach?

Prevalence and Persistence:   

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The most common childhood referral to psychiatric and psychological services in the UK Estimates as high as 8-10% of school population (Cooper, 2005 = 2-6%) – 3-5% in primary schools – that could possibly be 1 in each classroom 3:1 boys to girls in community samples whereas clinical samples are higher 9:1 – always a male bias -> this could be a referral bias rather than actually having the disorder as it is easier to spot the externalising behaviours in males than females as the females have less distracting behaviours Persisting into adulthood in 30-70% of cases -> behaviours around hyperactive and impulsivity would decrease while the inattention behaviours would be maintained Cultural issues? – Moffitt & Melchior (2007) argue the North American rate (6.2%) only slightly exceeded the European rate (4.6%). The highest rates emerged from Africa (8.5%) and South America (11.8%). – difference across cultures about the numbers of children being diagnosed with ADHD Japanese and Finnish children scored lowest, Jamaican and Thai children scored highest, and American children scored about average Important to look at the expectations of behaviours, cultural exceptions – which would be why there is more diagnosed children in certain countries

Associated Problems:   

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If we know the outcomes of problems, then it is easier to put the interventions in place Education problems – academic underachievement, exclusion Friendships/Peer problems – children with ADHD don’t have any deficit in social reasoning but rather in execution of appropriate social behaviour.  The IA type maybe ignored; the HI type activity rejected as behaviour can be seen as extreme Family dysfunction – cause or consequence of ADHD? Mental health –  Depression and personality disorders within adulthood  Drug abuse – result of medication in childhood?  Rejection from peers might lead to issues in self-esteem

Causes – Genetic Influences: 

Family, twin & adoption studies have suggested genetic and neurological influences e.g. Thapar & Stergiakouli, (2008) – does seem to suggest there is a strong influence of genetics -> this might lead to neurological changes of function that could lead to why someone develops ADHD

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Family studies – are biological relatives similarly affected more often than members of the general population? (25% and 30% of first-degree relatives of children with ADHD also meet criteria for ADHD) -> close genetic links Several studies show higher concordance rate (likelihood) in monozygotic twins (around 80%) vs. 0-33% for DZ twins – when you share the same genetic makeup, you are more likely to have ADHD but as it’s not 100%, it doesn’t explain everything Rate of concordance reported in children with ADHD raised by biological parents greater than those raised by adoptive parents.

Causes – Environmental:  

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Environmental interaction that doesn’t account for genetic factors Low birth weight (could be linked to maternal smoking, alcohol use, drug use & maternal stress - overall indicator of sub-optimal in utero environment) -> much higher % of children with ADHD having low birth weight – link between birth weight and ADHD Rates of ADHD in Low Birth Weight ( increases risk of ADHD See Banerjee, Middleton & Faraone (2007); Froehlich et al. (2011) for review

Causes – Brain Structure: 

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ADHD has neurological change -> likely that this cause has changed something around the frontal lobe -> frontal lobe = tasks around executive function, carrying out tasks, behavioural display etc. Individuals with ADHD have smaller total brain volume than the controls (particularly in prefrontal cortex) - Hill et al. (2003). May not be total brain volume but reductions in certain areas such as right prefrontal grey matter – Durston et al. (2004) Or enlarged areas of frontal lobe – right inferior frontal lobe – Garrett et al. 2008 May also be reduced activation in certain areas of frontal lobe i.e. prefrontal cortex – Brammer et al. (2005) Evidence is inconsistent in the exact role it plays but we know that there is some kind of neurological cause

Conclusions?       

Seem to be genetic risk factors that may interact with environmental influences These may cause neurological deficits in terms of structure or function of frontal lobe specifically Result in poor EFs and behaviour symptoms of ADHD Do seem to be structural and functional differences in ADHD vs controls in frontal lobes Are brain deficits – associated with cause or symptom? Exact differences vary across studies – suggesting a heterogeneous disorder – we know this as there is 3 sub-types but there is lots of aspects of this disorder Perhaps multiple pathways to the disorder? Could be a number of interactions between genes and environment

Executive Dysfunction Theory (e.g. Barkley, 1997):

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Cognitive theory which accounts with how ADHD links to executive dysfunctions Executive functions are cognitive processes such as planning, working memory, sustained attention which ae important for selection of appropriate behaviour Evidence suggest that children with ADHD have dysfunction on executive functions either altered activation or decreases volume in these parts of brain Neurotransmitters may also play a role as they are important to functioning of frontal lobes Neuropsychological tests can measure executive function and are often used to test executive functions Theory that is suggesting that ADHD is linked to specific weaknesses EF dysfunction failed to explain all symptoms i.e. Explains impulsivity and inattention but not hyperactivity (Willcutt et al. 2005) EF dysfunction not found in all children with ADHD – not universal theory that accounts for why all these behaviours occur Neuropsychological tests are complex involving various executive functions

Delay Aversion Theory (e.g. Sonuga-Barke et al): 

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Children with ADHD often choose the immediate smaller reward rather than waiting for a larger reward – compared to typically developing children -> give them sweets, tell them not to touch it an when you come back and you’ll give them more -> children with ADHD would choose it straight away Deficit is a motivational one rather than a cognitive one Individual try and escape or avoid delay – a motivational orientation Inattentiveness and hyperactivity reflect attempts to reduce subjective experience of delay in situations where is cannot be avoided

Dual Pathway Model:  

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Take both executive dysfunctions and delay aversions into consideration Evidence to suggest that ADHD is a neuropsychologically heterogeneous condition -> might be that these two different pathways are involved and so this would have implications in which interventions would be best (Faraone et al 2015) Pathways are distinct from each other but are related in some way of understanding ADHD Might be a dual pathway model- inhibitory deficits alongside delayed aversion – could explain more of symptoms  One pathway = deficits in Executive functions  Second pathway = delay aversion Multiple pathways to ADHD has implications for interventions (Lamek, et al 2017) There is clear evidence that EF and DA are distinct constructs (Lamek et al 2017) – but they are related to one another

Pharmacological Treatment:    

The prescription of psychostimulant medication is the most common treatment for ADHD They are called psychostimulant medications as they increase the arousal of the Central Nervous System Increase the activity of dopamine and noradrenaline (neurotransmitters) that are important in controlling attention and behavior Methylphenidate (Ritaline, Concerta, Metadate) are most common used in about 80% of cases

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Start working after around 45 mins – does usually lasts 4 hours – often taken 2 or 3 times a day

Effects of Medication:   

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Estimated that stimulant medication is effective for around 75% of children - although positive response does not necessarily mean ADHD diagnosis is correct Effective with a stronger dose and more effective for children rather than adolescents Meta-analysis data has shown how effective stimulant drugs are on behavioural, and emotional functioning of children with ADHD (Farone & Buitelaar 2010, Van der Oord et al. 2008) – limits impulsivity, aggression and increasing good classroom behaviors Think of ethical implications for asking children to taking medication that changes their behaviour Dupaul and Stoner (2014) summaries evidence that suggests stimulants have positive effect on sustaining attention, inhibiting impulsive responding, improve classroom behaviour, decrease aggression These effects stronger with higher doses – and seen across multiple settings More effective for children than adolescents

Limitations of Using Stimulants:      

Medication does not teach the child to compensate for their behaviour – need behavioural skill building strategies as well – might suppress the behaviour Medications do not bring about long-term permanent changes just immediate short terms gains – rebound if medication is stopped where behavior can get worse Heterogeneous disorder and drugs have different effects on individuals Long term outcomes unknown – possibly dangerous Does not acknowledge importance of environmental conditions Deskills individuals – removes responsibility and management of behavior without medication

Contingency Management:   

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Use of positive reinforcement is effective behaviour management strategy for all students DuPaul et al. (2012) – manipulating antecedent and consequent events in classroom – large effect on behaviour change Token reinforcement  Behavioural strategy which uses secondary reinforcers (tokens) to provide rewards  Immediacy, Specificity and Potency of the reward/token needs to be taken into account Response cost  Solely positive strategies rarely effective on their own need  Penalties for inappropriate behaviour  Use of token reinforcement with response cost increase in academic accuracy (Coles et al. 2005) Contingency contracting  Involves a negotiation of a contractual agreement between a student and a teacher.  The contact stipulates – desired classroom behaviour and consequences for complying or not Time out

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Time out from positive reinforcement Can be effective in reducing aggression and non-compliance (Fabiano et al. 2004) Should really be last resort after other procedures applied Only a short-term technique

A Combined Approach?    

The multi-modal treatment study of children with ADHD (MTA, 1999) – a randomized control trial compared medication vs behavioral interventions vs combination approach -> Combined treatments and medication, were better than behavioural treatment alone So, Leung and Hung (2008) showed that combination of drug and behavioural therapy were more effective that drug treatments alone in reducing symptoms. Need to think about ethical and moral implications of using drug interventions...