Attention Deficit Hyperactivity Disorder (ADHD) Pt 1 Flashcards
Attention Deficit Hyperactivity Disorder
“The essential feature of ADHD is a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning and development” [1]
Other CRUCIAL points:
* It is typically a CHRONIC, often lifelong condition, but the
impact/presentation can change over time – requiring lifelong monitoring and treament [2]
* It is a NEURODEVELOPMENTAL disorder [2]
* Usually seen in childhood, BUT not necessarily diagnosed at that time [2]
* > 50% of those diagnosed in childhood and adolescence continue to have
significant symptoms in adult life [2]
* It is thought to be a lifelong disorder! Why is it “seen” in childhood, but not diagnosed?
* ADHD is highly heritable – consider family members when assessing!
Prevalence
- 5-9% for children and adolescents [2]
- 5-10% [3]
- 3-5% for adults [2]
- 2.5-5% [3]
- Prevalence gap between AMAB:AFAB is shrinking – previously reported
much > AMAB vs AFAB - 2 : 1 in children [3]
- 1.6 : 1 in adults[3]
- AFAB more likely to have inattentive-type of ADHD
Burden of Illness
- In a 33-year follow-up study, children with ADHD were found to have a
greater risk of poor long-term outcomes as adults in almost every aspect
of life compared to their non-ADHD counterparts [2]. - Impaired executive functioning has the ability to impact almost every aspect
of a person’s life.
We see difficulties in occupation, academics, relationships, self-esteem – poorer health-releated
outcomes – increased risk of vehicular accidents, accidental injuries
Comorbidity
- MTA study > 70% of school aged children with ADHD have at least 1
other psychiatric condition [2] - Children with ADHD are 2-3 times more likely to have an intellectual
disability [2]
What do we treat first? What condition is causing what symptom? Is there overlap between
conditions? What barriers is this creating for the child?
As with most psychiatric conditions, there’s high comorbidity with ADHD, quite high actually
. So that tells you that the majority of people with ADHD or at least school-age children, based off of this study, had two or more psychiatric conditions. Children with ADHD are two to three times more likely to have an intellectual disability as well. So that’s something to keep in mind when we’re thinking about children in school.
DSM-5: Definitions of ADHD
- Two major categories [1]
- Inattention
- Hyperactivity/Impulsivity
- Combined manifestations [1]
- Combined Presentation
- “Predominantly Presentation” (Inattentive, Hyperactive/Impulsive)
Inattention
“Wandering off task, lacking persistence, difficulty sustaining focus, and disorganization not due to
defiance of lack of comprehension”
Hyperactivity
“Excess motor activity when it is not appropriate, excessive fidgeting, tapping, or talkativeness”
Impulsiveness
“Hasty actions that occur in the moment without forethought and that have high potential to harm
the individual. Desire for immediate rewards or inability to delay gratification”
DSM-5: Diagnostic Criteria of ADHD
Meets 6 or more of symptom criteria (17+ only requires 5)
Present for the last 6 months
Symptoms interfere with functioning or development
Several symptoms present prior to age 12
Symptoms present in two or more settings (i.e. home and school)
Symptoms not explained by another mental disorder, and do not occur exclusively during the
course of another psychotic disorder
6+ (if < 17 yro), 6 mo., fxn, prior to 12, 2+ settings
6 / 9 symptoms under 17 yro
5 / 9 symptoms in 17 and >
Combined needs
5 (or 6) from each criteria
17 year old and older, they actually only need five symptoms to be diagnosed
prevalence of comorbidities
We see a continuation of the learning disability. But look what happens as we get to adulthood, we start seeing co-morbid anxiety, depression, substance use we’ll talk about in a moment, and even borderline personality disorder
we do see co-morbid substance use quite commonly and ADHD. But what’s really interesting is that if you think about stimulants, you can actually abused them. There are substances that they are substance that can be abused. So there’s a lot of hesitation sometimes prescribing them because we’re afraid that somebody is going to misuse them. And we know that those with ADHD have higher rates of substance use or substance use disorder. those being treated, having their ADHD treated don’t have an increased risk of substance use. In fact, stimulants have a protective effect on substance use disorder
when you treat people with ADHD, they are less likely to have substance use disorder. And what that tells me is that it’s the symptomology. It is the the situation that the person struggling with ADHD is put in because of their condition that may predispose them to substance use
Natural History of ADHD
Hyperactivity
predominant
Inattention
predominant
Inattention and
Impulsivity
predominant
Inattention and
Impulsivity
predominant
Impulsiveness is, is similar in the sense that it’s kind of like erratic, but it’s, it’s more behaviors, right? So hasty actions that occur in the moment without forethought and that have the high potential to harm the individual. A lot of it has to do with even things like gambling, risky sex behaviors, and other big one with this group of people. And a lot of it has to do with the desire for immediate reward as opposed to delaying reward later on.
hyperactivity predominant. Then as we get older it tends to shift into inattentive. We start to see more impulsivity as we get to adolescents and adulthood. This is not all people. Some people will remain hyperactive their whole life. This is just, if anything, I see this more as if you were to take a snapshot of someone be ignited diagnosed in adulthood, you might see this. If you took a snapshot of someone diagnosed in childhood, you might see this
DSM-5: Severity of ADHD
Mild ADHD
Few, if any symptoms in excess of those required to make a diagnosis are present, and
symptoms result in no more than minor impairment in social/occupational function
Moderate ADHD
ADHD that is not mild or severe, but in-between
Severe ADHD
Many symptoms in excess of those required for diagnosis, or several that are severe, or
the symptoms result in significant impairment in social/occupational function
Risk Factors
Genetic
* Heritable, elevated risk with first-degree relatives who have ADHD
* No causal genes identified
Environmental
* VERY low birth weight - however, most do not develop ADHD
* Childhood trauma, neurological infections, EtOH/substances during pregnancy
* Toxins (ex: lead)
DSM-5: Differential Diagnosis(ADHD)
Oppositional defiant disorder
Intermittent explosive disorder
Learning disorder
Intellectual dev. disorder
Autism spectrum disorder
Reactive attachment disorder
Anxiety disorder*
Depressive disorder*
Bipolar disorder*
Borderline personality disorder
Disruptive mood dysreg. disorder
Substance use disorder*
Personality disorder
Psychotic disorder
Medication induced*
Neurocognitive disorders
Pathophysiology of ADHD
hypothesis summary
DA = Dopamine
Reuptake via DAT-1
NE = Norepinephrine
Reuptake via NET
Hypothesis Summary:
1) Folks with ADHD have a lower tonic (baseline) pool à leads to less presynaptic receptor binding (less neg. feedback) à less inhibition of DA/NE release
- When a stimulus causes an action potential in this neural pathway, we see a release of DA/NE à this release is not controlled (due to reduced
baseline inhibition) à overstimulation of postsynaptic receptors à impaired attention, hyperactivity, etc.
2) Stimulants reduce reuptake of DA/NE à facilitates a non-pathological tonic pool
3) An increased tonic pool results in a smaller discrepancy between baseline NT release and release post-action potential (phasic pool)
- More DA/NE in tonic pool results in increased presynaptic binding à when a stimulus/AP causes DA/NE release there is a non-pathological
negative feedback in place to control these bursts of neurotransmitters à postsynaptic receptors are not overstimulated
Stimulants. What they do is they actually reduce the re-uptake of dopamine and norepinephrine. So they’re working here. They’re blocking the transporter so that we have a higher tonic pool. So we’re increasing throughout the day that baseline level of norepinephrine and dopamine so that there’s more negative feedback
Pathophysiology of ADHD
Altered brain anatomy
* Impaired connectivity between prefrontal cortex and precuneus
* Reduced volume of PFC, anterior cingulate cortex, caudate, and cerebellum
Neurotransmission dysregulation
* Altered expression of DA/NE receptors (pre/post-synapse)
* Altered baseline or functional release of DA/NE from pre-synapse
see the graph for diff classifications
ok
