Developmental psychopathology
Refers to the study of childhood disorders
–> understanding the children behaviors cross the line from the normal difficulties of childhood into the abnormal
Predominantly inattentive type
Diagnosed if 6 or more symptoms of inattention, but fewer than 6 symptoms of hyperactivity-impulsivity are present
Predominantly hyperactive-impulsitivity type
Diagnosed if 6 or more symptoms of it + less than 6 symptoms of inattention are present
Combined type
Includes 6 or more symptoms of both are present
ADHD behavioral problems, sometimes are severe enough to be diagnosed as a conduct disorder.
What is this ?
Engaging in serious transgressions of societal norms for behavior
–> repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate norms are violated
What are the differences in neurological functioning + cerebral blood flow in children with ADHD ?
- PFC is smaller in volume + shows abnormal activation when children try to inhibit their responses (Immaturity hypothesis)
–> regulates attention, organization planning
- Catecholamine neurotransmitters, which are involved in inhibiting impulses function abnormally
–> include dopamine, serotonine, norepinephrine
- Less connectivity between PFC + emotional, motor + memory areas
Treatments for ADHD
- Stimulant drugs such as Ritalin, Dexedrine etc
- Psychosocial therapy
- Working memory training
What are the advantages of the usage of stimulant drugs ?
- Decreases the demanding, disruptive + noncompliant behavior
- Increases in positive mood, goal directed behavior + interactions with others
–> works by increasing the levels of dopamine + inhibiting its reuptake
Disadvantages of the usage of stimulant drugs ?
- May increase the frequency of tics in children
- Decrease in their growth rate
- Risk of abuse
Epidemiology of ADHD in Childhood
- Mainly diagnosed in elementary school
- Boys are 2x more likely to develop it
- Usually comes along with a severe learning disorder, making it hard to concentrate in school
- Poor relationships with others
PREVALENCE: 5%
What are the 3 possible types of ADHD ?
- Combined type
- Predominantly inattentive type
- Predominantly hyperactive-impulsive type
Epidemiology of ADHD in Adulthood ?
- In 50% symptoms persist into young adulthood
- Increased risk for antisocial personality disorder, substance abuse, marital problems, frequent job changes
PREVALENCE: 2.5%
A systematic, computerized WM training was used to assess if it will lessen ADHD symptoms.
What did the results yield ?
- Improved WM performance + increased brain activity in the DLPFC + parietal association cortices
–> indicates plasticity of the neural systems of the WM
- Heightened motivation
- Maintenance of concentration + attention
- Withholding of impulsive + inappropriate behaviors
Delay aversion hypothesis
Behaviors of ADHD children are due to an underlying motivational style rather than the dysfunction of regulatory systems
–> motivated to escape or avoid delay (delay aversion)
Dual pathway model
Suggests that the combined type of ADHD has 2 distinct subtypes with distinct psychological + developmental processes leading to ADHD
–> explains neuropsychological heterogeneity in ADHD
Which tasks where used to assess inhibitory control vs delay aversion in ADHD children ?
Standard stop signal task
+ Choice delay task
–> together they correctly identify 90% of ADHD cases + confirm that delay aversion and poor inhibitory control are core but still unrelated
Dysregulation of thought + action pathway
DTAP
Characterizes ADHD predominantly as a disorder of the regulation of thought + action resulting from inhibitory disfunction
–> higher order cognitive control circuits are messed up (pre-)frontal regions and their connections to the basal ganglia and striatum
NO DIRECT PATHWAY
2 types: cognitive vs behavioral dysregulation
Motivational style pathway
MSP
Characterizes ADHD as predominantly a motivational style mediated by the emergence of delay aversion
- Reward circuits are messed up, meaning ventral-striatal network incl. NAC
(meso-limbic branch of the dopamine system)
Trigger: shortend delay gradient
- Cultural norms + values
Trigger: delay related demands
Triple pathway model of ADHD
Includes the
- Dorsal fronto-striatal loop (DTAP)
- -> inhibition, cognitive control - Ventral fronto-striatal loop (MSP)
- -> delay aversion, reward processing - Temporal processing deficit (TPD)
- -> frontal cerebellar loop, general WM problems
Neuropsychological heterogeneity
Means that only a minority of ADHD patients show deficits in each domain and that some patients with ADHD will perform in the normal range
–> there are multiple (hetero) explanations for ADHD - dual pathway
Transfer effects
Refers to the effect that knowledge or abilities acquired in one area have effects on problem solving or knowledge acquisition in other areas
–> greatly shown in WM tasks
Gender differences in ADHD
Men are 2x more likely to have ADHD
–> girls are more underidentified, because they then tend to be inattentive
ex.: teacher might rather classify inattentive girl as shy or dreamy
Which task accounted for the TPD, thus suggested that there is a 3rd pathway ?
E.g. Duration discrimination
–> difficulty with estimation of how much time has passed
What does Partial remission of ADHD mean ?
Full criteria for ADHD have been met before in the past, but for the past 6 months fewer of the symptoms are shown, thus not able to fully meet the DSM 5 criteria
“getting it back but not to the full extent”
–> still functionally impaired
