PSYC 251 ADHD and ASD

4 key characteristics of neurodevelopmental disorders

• often onsets during infancy and early childhood with a steady course

• deficits produce impairments

• comorbidity with other disorders with a childhood onset

Prevalence of ADHD

• Australia: 5% of children under 18

• affects boys more than girls

• 70% cases persist into adulthood

what are the 9 inattention symptoms of ADHD

• fails to pay close attention

• difficulty sustaining attention

• doesn’t seem to listen when spoken to

• doesn’t follow instructions or fails to finish tasks

• poor time management

• avoids tasks requiring sustained mental energy

• looses things

• easily distracted

• forgetful

what are the 9 Hyperactive symptoms of ADHD

• fidgeting

• leaves seat

• runs around/climbs where inappropriate 

• unable to do quiet activities

• always on the go

• talks obsessively 

• blurts answer before a question is finished

• trouble waiting for their turn 

• interrupts others

what is the DSM 5 diagnostic criteria for ADHD

• 6+ (children) 5+ (adults) of inattentive and/or hyperactive

• for at least 6 months

• symptoms inappropriate for developmental age

• several symptoms before age 12

• several symptoms present in two or more settings

• impairment

• not better explained by another disorder

Differential diagnoses for ADHD

Anxiety

• similarity: inattention

• difference: but it is caused by fear, worry or rumination

Conduct disorders

• similarity: impulsivity, difficult emotional regulation

• differences: antisocial behavior, hostility, defence

what are the 9 things involved in ADHD diagnoses

• Birth and medical history

• Developmental and social history

• reports

• symptoms

• referrals

• rating scales

• observation

• structured and semi structured diagnostic interviews

• cognitive and executive functioning

Developmental changes in ADHD - Preschool

• external symptoms (hyperactive)

• difficulty to differentiate if its disordered or developmentally normal

• Comorbid with: ODD, Anxiety

Developmental changes in ADHD - Childhood and Adolescence

• inattentive more prevalent than combined - persists with age more than hyperactivity 

• underachievement at school

• peer relationship problems 

• Comorbid with: Anxiety, MDD, ASD, sleep disorders

Developmental changes in ADHD - Adulthood

• Emotional Instability

• comorbid with: MDD, Anxiety, PDs

4 Perinatal ADHD factors

• Maternal stress

• prematurity

• low birth weight

• elevated testosterone exposure

3 Environmental ADHD factors

• Smoking and drinking in pregnancy

• lead exposure

• infections 

3 Temperament ADHD factors

• Behavioural inhibition

• effortful control

• negatove emotionality 

3 Biological/Physiological factors

• 70-90% heritable

• Genes x environment

• Visual and hearing impairments

CNS and ADHD

Hypoarousal of the CNS makes it difficult to sustain attention, hyperactive behaviors used to autoregulate

Dynamic Developmental Theory

• Dopaminergic transmission impaired

• Less dopamine = harder for stimuli to be rewarding

• critical window (where reinforcement by dopamine is possible) is narrower

Dopamine Transfer Deficit theory

• Base line dopamine is normal

• but amount of dopamine used for reinforcement altered to point of ineffectiveness

Pharmacological treatments for ADHD

stimulants

• Methylphenidate (Ritalin, concerta)

• Dexamphetamine (Adderall, Vyvanse, Dexedrine

• Mixed amphetamine salts

How do stimulants treat ADHD

Increase availability of synaptic dopamine and norepinephrine

Side effects of stimulants

• Appetite/weight loss

• GI upset

• trouble sleeping

• headaches

• worsening of MDD and ANX

• RARE: delayed growth in first 2 years of treatment

Psychosocial treatments for ADHD

• Behavioural therapy

• parent training

• CBT

onset of ASD

• Starts in childhood but also seen in early adolescence

• typically diagnosed in first few years of life

Prevalence of ASD

• 1-2% of population

• 42% increase from 2018 to 2022

• more prevalent in under 25 than over

• peak prevalence in 10-14 yrs

• effects males for then females

• 73% have a profound disability

Communication and interaction symptoms of ASD

• Deficits in social and emotional reciprocity

• deficits in nonverbal communication

• deficits in developing relationships

Restricted/repetitive behavior symptoms of ASD

• Repetitive movements or speech

• insistence on sameness and routine (distress at changes)

• Fixated interests

• Hyper/Hypo reactivity to sensory input

what are the additional factors regarding ASD symptoms

• all symptoms must be present in early developmental period (but may not fully manifest early)

• symptoms interferer with functioning

• symptoms not better explained by another disorder

Catatonic behaviors of ASD

• rigidity

• strange movements

• remaining in uncomfy positions 

• erratic movement

• echolia

Diagnoses of ASD

• Assessment: clinical observation/interviews, questionnaires

• multidisciplinary team

• Psychological assessment: history, previous assessments,  semi structured play

• Assessment of risk

Early development ASD symptoms

• no smile by 6 months

• mimicking by 9 months

• babble or coo by 12 months

• no pretend play by 18 months

• delayed speech by 24 months

inheritance of ASD

37-90% (based on twin studies)

4 Perinatal ASD factors

• Advanced parental age

• low birth weight

• foetal exposure to valproate

• premature

Chemical ASD factors

• Brain Hyperconnectivity

• Lack of synaptic pruning

Treatments for ASD

• Speech and language therapy

• OT

• Discrete trial training: step by step instructions

criticism of ABA

• Reinforces children to act typical without addressing needs