Week 8 - ADHD

What are the two domains and three presentations of ADHD?

• Inattention

• Hyperactivity/impulsivity

• Combined

What ADHD presentation will most people have?

A combined presentation, with symptoms of both hyperactivity and inattention

Is a particular group more likely to have a singular ADHD presentation of inattention?

Yes, adults and particularly girls

What is the prevalence of ADHD in children?

4-6%

What is the prevalence of ADHD in adults?

2-3%

Persistence of ADHD in adolescence and adulthood

ADHD often persists in adolescence (50-80%) and adulthood (30-50%) but with different symptomology (e.g. a hyperactive presentation in childhood to an inattentive presentation in adolescence/adulthood)

Demographic differences in ADHD

2.5/1 male to female ratio in CYP, however this is due to referral bias - the presentations we think are more ADHD are the hyperactive presentations which is what parents/teachers notice and complain about, thus if a girl is showing an inattention presentation, they may be less likely to be picked up and diagnosed

Diagnosis of ADHD in CYP

• No objective markers of ADHD

• Psychiatric interview of parent (if talking about a child) or patient (if talking about an adult) 

• Rating scales (e.g. Conner’s Rating Scale is one of most widely used)

• Neurological tests (QB tests)

• Diagnostic criteria (valid across cultures and settings)

Diagnostic criteria of ADHD (DSM5)

• Age-misaligned hyperactivity-impulsivity and/or inattention for at least 6 months and in at least two different settings

• Significant impact on everyday life and functioning

• At least some of the symptoms appeared in early-mid childhood - this is problematic because some people have not experienced symptoms as a child, and this could prevent them from receiving a diagnosis

Differential diagnosis

ADHD is usually the first thing a parent/teacher will think of in relation to what could be going on with a child, however it could also be:

• Oppositional defiant disorder

• Intellectual disability

• Anxiety disorders

• Depressive disorder

• Epilepsy

• Asthma - sometimes children treated for asthma can develop symptoms similar to those of ADHD

And more. This is one of the reasons it takes clinicians a long time to diagnose children

Liability threshold model

Neither genetic or environmental factors are sufficient to cause ADHD, instead, genetic and environmental risk factors interact/accumulate and, when a certain threshold is overcome, ADHD symptoms manifest (this is particularly pertinent in early life, e.g. things that happen during pregnancy or right after birth that may affect brain development)

Genetic risk factors for ADHD

Polygenic risk (no single gene), infections, maternal stress

Environmental risk factors for ADHD

• Toxins, alcohol, cigarette smoking during pregnancy

• Nutrient deficiencies

• Obstetric complications

• Low birth weight

• Premature birth

• Maternal hypertension

• Maternal obesity

• Stress

• Infection

• Poverty

• Trauma

Low socioeconomic backgrounds and ADHD

Cannot simulate the protective factors to protect against the development of ADHD in low socioeconomic backgrounds as children from these backgrounds do not have the same resources

Executive function theory of ADHD

Theorises that people have ADHD because their brains don’t work very well/have not developed as it should - they have deficits in vigilance, response inhibition, working memory and planning

Support for executive function theory of ADHD

People with ADHD show structural and functional alteration of pre-frontal, fronto-parietal, and fronto-striatal circuits, connection between brain areas and prefrontal and frontal areas

Strengths and weaknesses of the executive function theory of ADHD

• Good theory as explains the inattention part of ADHD - a lot of the inattention symptoms are due to altered brain functions

• But doesn’t explain hyperactivity, and not all children and adolescents with ADHD experiences problems with executive functions

State regulation theory of ADHD

People with ADHD struggle to regulate their level of attention (arousal) in specific conditions. Cortical and autonomic hypoarousal leads to inattention. Hyperactivity is a strategy to up-regulate arousal and attention, such as by stimming. Emotional dysregulation in this context means difficulties in regulating autonomic arousal

Techniques to upregulate arousal

Adults can do this by drinking caffeine, however children cannot do this so may use behavioural strategies such as “stimming”

Strengths and weaknesses of state regulation theory of ADHD

• Strengths - explains hyperactivity, inattention and impulsivity, physiological evidence shows patterns of lower sympathetic activation (hypoarousal) in people with ADHD

• Weaknesses - is there an optimal state of arousal? If so, what is this, and it is possible to measure this? Model might place too much emphasis on “state: and not enough on cognition, executive factors etc.

Delay aversion theory of ADHD

Theorises the main problem with ADHD is altered processing of rewards and difficulties, viewing symptoms as a drive to escape or avoid the negative emotional states caused by waiting. “Escape” behaviours such as fidgeting, excessive talking etc. are conceptualised as functional attempts to speed up time or to avoid the internal experience of waiting

Evidence for delay aversion theory

• For executive functioning, there are altered functioning/structure of brain systems involved in reward processing

• People with ADHD have lower dopamine making processing positive and negative rewards more difficult

• Negative reinforcement rarely works for children with ADHD, probably because there is a misalignment in how they process rewards, however positive reinforcement works well

Strengths and weaknesses of delay aversion theory

• Strengths - brain studies have shown that people with ADHD have hyperactivation in brain regions related to processing aversive events (e.g. amygdala, prefrontal cortex) when anticipating a delay which supports the idea that waiting is a negatively valued experience for them

• Weaknesses - might not be the case for those with a purely inattentive presentation

Why is ADHD problematic?

• Academic performance and employment - people with ADHD drop out of degrees at a higher level than neurotypicals do

• Addictions - people with ADHD more likely to engage in unhealthy and risk-taking behaviours, perhaps to upregulate arousal

• Health problems - obesity, vision disorders, allergies, asthma, diabetes

• Quality of life - poorer, especially in relation to social/emotional functioning

• Emotional and conduct problems - social exclusion in school, bullying/criminal behaviours

Why is ADHD called a neurodevelopmental disorder?

Because the condition affects the body as well as the brain

Are there strengths of ADHD?

Yes, people with ADHD are enthusiastic, can excel and perform at a much higher level than neurotypicals at something specific they are passionate about. They have adaptive characteristics like courage, energy, resilience, creativity, hyper-focus and many others (Sedgwick et al., 2019)

How is ADHD managed for under 5’s? (NICE)

1. ADHD-focused group parent training - working with parent to understand how ADHD is affecting parents life (as ADHD mostly becomes problematic in preschoolers because parents struggle to manage them)

2. If ADHD symptoms still impairing, consider medication

How is ADHD managed for over 5’s? (NICE)

1. Group-based ADHD support - parents and children with ADHD to learn about it, teach behavioural management and show parents how to manage them

2. If ADHD symptoms still impairing, consider mediation

3. For adolescents/young people, CBT if symptoms are still impairing with medication

Do we provide effective parent training in the UK?

No, because the NHS does not have the resources/money, we rarely provide effective parent training. Apps/websites might be more helpful and cost-friendly, and are being co-produced at the moment

How to manage ADHD with co-occurring ODD/CD? (NICE)

Give parent training focused on symptoms associated with ODD/CD

How to manage ADHD in adults? (NICE)

1. Medication

2. Supportive psychological intervention if patient asks and/or if medication is ineffective/not tolerated (this is something the NHS is currently not providing, so people usually do this privately)

Non-pharmacological interventions for ADHD

• CBT - reduces level of perceived stress

• Mindfulness - increase the level of agency, allow them to accept the experiences they are having

• Multi-nutrient supplementation

• Sports - help with ADHD because they target the neuro-biological hypoarousal in the brain, helps to get more oxygen in the brain etc., however it won’t cure ADHD

• No significant effects of cognitive training or neurofeedback

• Unclear findings for massage therapy, brain stimulation, dietary interventions or supplements, physical activity, but these are safe, well tolerated and may be beneficial for some CYP with ADHD

What conditions commonly co-occur with ADHD?

• Conduct disorder/oppositional defiant disorder (10x vs. NTs)

• Depression (5x)

• Anxiety disorder (3x)

• Overlap with other neurodevelopmental disorders (autism, communication, learning or motor disorders), intellectual disability, Tic disorders

• Substance us disorders (adolescence), sleep disorders

• Medical comorbidities - obesity, asthma and diabetes, type II (Arrondo et al., 2022)

• Emotional dysregulation

• Sluggish cognitive tempo